,transcriber's ,notes3 ,bold1 italics1 superscript and subscript text have been trancribed as text1 text1 text1 and text1 respectively4 ,small capitals have been replaced with capitals4 ,letters between square brackets such as ,t and ,v indicate ,t- and ,v-shaped symbols rather than letters4 ,more transcriber's ,notes may be found at the end of this text4 ,soldering1 ,brazing and ,welding ,,edited ,,by ,,bernard ,e4 ,,jones ,editor of 8,work0 ,with #gh ,illustrations ,illustration ,,funk ,,wagnalls ,,company ,,new ,,york and ,,london #aiag ,,editor',s ,,preface ,this handbook1 which explains in detail a variety of processes common to general metalworking1 has been written by a number of thoroughly practical men1 by whom it was contributed in another form to 8,work10 the illustrated weekly journal of handicrafts and mechanics4 ,its appeal is to everybody who makes any attempt at working in metals1 inasmuch as at least one of the processes--soldering1 brazing or welding--will be met at a very early stage in the beginner's experience4 ,this handbook will be found a complete workshop guide to the usual methods of soldering and brazing1 and will form an excellent introduction to the modern electrical and oxy-acetylene welding processes1 to do complete justice to which1 however1 a separate handbook would1 of course1 be necessary4 ,if readers encounter difficulty in any of the matters treated in this book1 they have only to write to 8,work10 in whose columns 7but not by post7 help will be willingly afforded4 ,b4 ,e4 ,j4 ,,contents ,,chapter ,,page #a4 ,,various ,,processes ,,of ,,joining ,,metals #a #b4 ,,soft ,,solders #d #c4 ,,fluxes ,,used ,,in ,,soft-,,soldering #ab #d4 ,,soft-,,soldering ,,with ,,the ,,copper ,,bit #ag #e4 ,,soft-,,soldering ,,with ,,blowpipe ,,or ,,bunsen ,,burner #cg #f4 ,,soldering ,,aluminium #eg #g4 ,,wiping ,,joints ,,on ,,lead ,,pipes #fd #h4 ,,hard-,,soldering ,,with ,,silver ,,solder #ge #i4 ,,soldering ,,gold ,,and ,,silver ,,jewellery #hc #aj4 ,,brazing #hi #aa4 ,,welding ,,iron ,,and ,,steel ,,under ,,the ,,hammer #ajh #ab4 ,,making ,,blowpipes #aab #ac4 ,,managing ,,blow-,,lamps #aah #ad4 ,,making ,,blow-,,lamps #abb #ae4 ,,electric ,,and ,,thermit ,,welding ,,briefly ,,considered #abi #af4 ,,oxy-,,acetylene ,,welding #acd #ag4 ,,lead-,,burning #aej ,,index #aee ,,soldering1 ,,brazing ,,and ,,welding ,,chapter ,i ,the ,various ,processes of ,joining ,metals ,apart from the use of rivets1 screws1 etc41 metal is commonly joined by soldering1 brazing1 or welding1 three groups of processes that have one thing in common--the use of heat to fuse either the metals themselves or an alloy which is interposed to consolidate the joint4 ,the word 8solder0 is derived through the ,french from a ,latin word meaning 8solid40 ,soldering may be 8soft0 or 8hard40 ,soft-soldering uses lead-tin alloys which are easily melted in a bunsen gas flame or with a hot iron or bit2 while hard-soldering employs a silver-copper alloy1 to melt which a mouth blowpipe at least is necessary4 ,brazing is hard-soldering with spelter 7brass71 and a forge or a heavy blowlamp or a powerful blowpipe must be employed to provide the heat4 ,welding is a fusion process which in the past was almost entirely confined to wrought-iron and steel1 these metals possessing the property of weldability to an extent unknown in the case of any other metals4 ,the blacksmith's process of welding is to heat the iron or steel until the surface of the metal becomes pasty1 and then to bring the two pieces into intimate contact by hammering on the anvil4 ,of late years the welding of iron1 steel1 copper and some other metals has been rendered possible by the use of certain electrical and chemical methods and--most important of all--by the use of the oxy-acetylene blowpipe1 the process being known as 8fusion welding0 or 8autogenous soldering10 the word autogenous implying that the process is complete in itself and independent of the use of any extraneous substance such as solder4 ,the thermit process1 of which so much has been heard1 and which is briefly dealt with later1 is the fusion welding of iron and steel by means of the intense heat produced by the combustion of a special chemical compound4 ,perhaps the oldest of the autogenous soldering processes is 8lead-burning10 in which the flame of an airo-hydrogen blowpipe is brought to bear upon the lead1 the joint being fed with a strip of the same metal4 ,soft-soldering is an operation that the beginner will not find nearly so difficult as hard-soldering or brazing1 and although the strength of joints made by it is not nearly equal to that produced by the methods named1 it fills a useful place within its scope4 ,it is purely a surface union--that is1 the solder adheres to the faces in contact in much the same manner as an adhesive sticks to metal2 but with the assistance of fluxes1 the contact is made so intimate that some force is necessary to break the joint4 ,soft-soldering is also of use where brazing would simply mean the ruin or destruction of the metals1 as in the cases of lead1 poor-quality brass1 pewter1 tin1 zinc1 and in tinplate and galvanised iron4 ,in silver-soldering and brazing1 the silver or spelter that fuses to form the joint alloys itself so intimately with the copper or brass that it actually becomes part of the piece itself1 and for all practical purposes cannot be distinguished from it4 ,but soft-soldering is not always inferior to hard-soldering4 ,indeed1 the surface nature of the soldering often constitutes its value4 ,the strongest joints of all are produced by fusion welding1 as will be duly understood from later chapters4 ,,chapter ,,ii ,soft ,solders ,a solder should melt at a slightly lower temperature than the metals which it unites1 and should possess the quality of alloying with the two surfaces1 thus effecting a sound and true metallic joint4 ,ordinary soft solders are lead-tin alloys1 and the larger the proportion of lead the commoner is the solder said to be4 ,at an extreme is plumber's solder1 consisting of #b parts of lead to #a part of tin1 and1 at the other1 the best blowpipe soft solder1 which contains #b parts of tin to only #a part of lead4 ,in the ordinary way1 a 8coarse0 or 8common0 solder is #b parts of lead to #a part of tin2 a 8fine0 or 8medium0 solder1 #a part of lead to #a part of tin2 and a 8very fine0 or 8best0 solder1 #a part of lead to #b parts of tin4 ,eutectic ,alloys4--,lead-tin solders are eutectic alloys--that is1 they are examples of the phenomenon of a combination of two metals melting at a temperature lower than one of them would if melted separately4 ,thus1 lead melts at about #cbh ,c41 and tin at about #bcb ,c41 yet reference to the following table1 given by ,mr4 ,a4 ,h4 ,hiorns1 will show that the 8commonest0 solder mentioned fuses at #cjc ,c41 and the 8best0 at #age ,c4 ,melting points of lead-tin alloys ,tin ,lead ,melting point 7,c47 #aj #ij #cjc #bj #hj #bgh #cj #gj #bee #dj #fj #bcj #ej #ej #bje #fj #dj #ahg #fc #cg #age #gj #cj #ahe #hj #bj #aih #ij #aj #bae ,hardness of ,solders4--,according to the before-mentioned authority1 ,saposhniko1 in #aijh1 determined the hardness of various lead-tin alloys by ,brineli's method1 by which a steel cone is forced into the metal4 ,the results he obtained are as follow3 ,lead #ajj #ij #hj #gj #fj #ej #dj ,tin #j #aj #bj #cj #dj #ej #fj ,hardness #ci #aja #abaf #ade #aeh #aej #adf ,lead #cd #cc #cb #cj #bj #aj #j ,tin #ff #fg #fh #gj #hj #ij #ajj ,hardness #afg #aed #adf #aeh #aeb #acc #da ,these results1 says ,mr4 ,hiorns1 show that the hardest alloy is the one with #ff 7about #b parts7 of tin and #cd 7about #a part7 of lead1 which also is the one having the lowest melting point of all the lead-tin alloys4 ,the results also show that tin is slightly harder than lead4 ,compositions of ,soft ,solders4--,as already shown1 solders vary in fusibility according to their composition1 and the choice should be determined by the nature of the work and the properties of the metal to be soldered4 ,should a solder be used of too high a melting-point1 the metal will itself be fused before the solder begins to flow4 ,a point to be particularly observed is that the introduction of a foreign substance into the solder--for example1 the addition of a little zinc to a pot of 8very fine0 solder--will utterly spoil it and render it unworkable4 ,to remove zinc from solder1 melt the solder in a pot1 take it off the fire and stir in powdered sulphur or brimstone until the whole is of the consistency of wet sand4 ,replace the pot on the fire and melt1 but do not stir the contents4 ,the sulphur and zinc will rise to the surface and form into a cake4 ,now take the pot off the fire and carefully remove the cake without breaking by employing two pieces of hoop iron with bent ends4 ,it is false economy to use a rough solder for fine work on the score of cheapness1 since more solder is required for a given job on account of the rough particles of solder clinging to the work2 moreover1 the rough appearance of the soldering may completely spoil the job4 ,the table on the opposite page gives the fluxes and the compositions of soft solders suited to a number of different metals4 ,making ,solder ,strips1 ,wire1 ,tears1 etc4--,only clean1 pure tin and pure lead should be employed4 ,the lead is first melted and then the tin added4 ,when all is melted1 place a piece of resin on the molten metal to act as a flux1 and after well stirring1 the solder is made into strips by pouring from a ladle4 ,solder should not be poured into sand4 ,it may be poured into strips on an oiled sheet of black iron1 preferably corrugated to accommodate the strips4 ,in the absence of a corrugated iron sheet1 some workers use a ladle resembling a large spoon with a hole about #a_/af in4 in diameter near the end4 ,to form the strips1 get a ladle full of solder1 place it on a flat iron sheet2 then1 tilting the ladle to allow the solder to flow over the hole1 quickly draw the ladle across the sheet4 ,a thin strip of solder should thus be formed1 and the thickness of the strip may be varied by increasing or decreasing the diameter of the hole in the ladle4 ,a button of solder usually forms at one or both ends of the strip1 and this excess should be melted off the strips by just dipping the ends into the molten solder in the pot4 ,,soft ,,solders ,,for ,,various ,,metals ---------------------------------------- ---------------------------- ,soft ,solder ------------------------ ,metal to be ,flux ,other soldered ,tin ,lead constit- uents ---------------------------------------- -------------------------- ,aluminium stearin see table on p4 #ei ,brass #azinc chloride1 resin #ff #cd ,gunmetal or ammonium #fc #cg ,copper chloride #fj #dj ,lead tallow or resin #cc #fg ,block tin zinc chloride #ii #a ,tinplate zinc chloride or resin #fd #cf ,galvanised steel hydrochloric acid #eh #db ,zinc hydrochloric acid #ee #de ,pewter gallipoli oil #be #be bismuth1 #ej ,iron and steel ammonium chloride #ej #ej ,britannia metal tallow or resin #be #be bismuth1 #ej ,gold zinc chloride #fg #cc ,silver zinc chloride #fg #cc ,bismuth zinc chloride #cc #cc bismuth1 #cd ---------------------------------------- -------------------------- ,footnote #a3 ,zinc chloride is the ordinary 8killed spirits40 ,solder wire is very handy for small work1 and can be made in the following way3 ,roll a sheet of stiff writing or drawing paper into a conical form1 rather broad in comparison with its length2 make a ring of stiff wire to hold it in1 attaching a suitable handle to the ring4 ,the point of the cone should first of all be cut off to leave an orifice of the size required4 ,it should then be filled with molten solder1 and held above a pail of cold water1 and the stream of solder flowing from the cone will solidify as it runs and form the wire4 ,if held a little higher1 so that the stream of solder breaks into drops before striking the water1 it will form handy elongated 8tears0 of metal2 when it is held still higher1 each drop forms a thin concave cup or shell1 and each of these forms will be found to have its own peculiar uses in blowpipe work4 ,the method adopted for granulating tinman's solder1 which is very rarely called for1 is as follows3 ,place a piece of wood1 well greased1 over a tub containing water1 and by gently pouring the molten alloy from a distance in a small stream on to the greased board1 the metal is broken up into a large number of very fine shots1 which run off the board into the water and are immediately cooled4 ,the fine shots are then taken from the water and gently dried4 ,making ,solder from ,pewter4--,this alloy is composed of variable proportions of tin and lead1 the average composition being about #d parts of lead to #a part of tin4 ,if old pewter is to be utilised for making solder1 tin will have to be added to the molten pewter4 ,thus1 to convert #e lb4 of average pewter to 8coarse0 or 8common0 solder1 add #a lb4 of tin2 to 8fine0 or 8medium10 add #c lb4 of tin2 and to 8very fine0 or 8best10 add #g lb4 of tin4 ,the respective proportions of lead and tin will then be #b and #a2 #a and #a2 and #a and #b4 ,after the proper quantity of tin has been added1 mix some powdered sal-ammoniac with the molten metals1 and well stir the alloy2 it is then ready for pouring into the moulds4 ,making ,coarse ,solder from ,composition ,piping4--,good composition piping is made of nearly all tin1 or an alloy of tin and lead1 in which the former metal is in excess1 and formerly was much used by plumbers in the making of coarse solder1 as the material consisted of odd pieces of small value4 ,as1 however1 a great deal of composition tubing is made out of old metals of which lead1 tin1 antimony1 arsenic1 and zinc form the alloy1 it is not advisable to introduce it into solder4 ,should it be done1 the melting point of the solder would be raised1 and in applying it to the lead to be joined together1 would probably partly melt it4 ,neither do the metals named alloy in a thorough manner1 but partake more of the nature of a mixture in which the constituents partly separate when making the joints1 and some1 especially zinc1 show as small bright lumps on the surface4 ,joints wiped with what is usually called 8poisoned metal0 are difficult to make1 almost invariably leak when on water service pipes1 and are dirty grey1 instead of bright and clean4 ,the zinc could be removed from the mixture by the method already given4 ,combined ,solder and ,flux4--,this consisted of equal parts of lead and tin made into fine tubing and afterwards filled with flux having resin as a base4 8,tinol0 is a paste made of finely powdered solder and a special flux1 and there is also 8,tinol wire0 having a core of flux4 ,a 8magic0 solder1 sold by hawkers1 consists of the above tubular flux-filled solder of such low melting point that it can be fused in the flame of a lighted match4 ,soft ,solders that ,melt in ,boiling ,water4--,the following soft solders melt at a temperature lower than that of boiling water3 #a part tin1 #a part lead1 and #b parts bismuth1 melting point about #bjj ,f42 #h parts lead1 #d parts tin1 #ae parts bismuth1 and #c parts cadmium1 melting point #adj to #aej ,f42 #f parts lead1 #g parts bismuth1 and #a part cadmium1 melting point about #ahj ,f4 ,to ensure the alloys melting at the temperatures stated1 the metals of which they are formed should be free from impurities1 and care should be taken to prevent oxidation while making the alloys4 ,when melting the metals1 that having the highest melting point should be melted first1 with a layer of resin over it1 the other metals being added in the order of their melting points4 ,the alloy should then be well stirred with a wooden stick1 and poured quickly into moulds4 ,re-melting and ,overheating ,solder4--,after solder has been re-melted a number of times or has been overheated1 its content of tin will be reduced1 and the solder will become poorer and coarser4 ,the tin melts earlier than the lead and1 being the lighter of the two1 floats over it1 and is thus fully exposed to the air1 the oxidising effect of which on heated1 molten metal is extremely active4 ,the oxidised tin forms a dross1 from which most of the tin may1 however1 be recovered by melting it with powdered charcoal1 which combines with the oxygen and frees the tin4 ,the addition of a little fresh tin is desirable4 ,,chapter ,,iii ,fluxes ,used in ,soft-soldering ,why a ,flux is ,required4--,the great essential to successful soldering is the chemical cleanliness of the surfaces to be united1 and the proper use of a flux4 ,although work may be filed or scraped perfectly bright and clean1 this is not the kind of cleanliness which is alone sufficient2 there is always in course of formation a film of oxide present1 and the duty of the flux is to dissolve this and keep any more from forming4 ,then1 and not until then1 will the molten solder 8run0 and spread over faces in the intimate contact necessary4 ,if this vital precaution of cleaning and fluxing is always observed1 the difficulties which many beginners experience in effective soldering will vanish4 ,variety of ,fluxes4--,there are a good many fluxes employed1 including tallow 7largely used for lead and pewter71 resin 7used for lead1 compo-pipe1 and tinned metals71 hydrochloric acid1 diluted 7for zinc and galvanised iron71 and chloride of zinc 7the well-known 8killed spirit074 ,the last-named is the most generally used1 being suitable for tinplate1 tinned iron1 new zinc1 copper1 and brass4 ,sal-ammoniac is also utilised1 sometimes in conjunction with chloride of zinc4 ,the small worker who does but a moderate amount of soldering will find it convenient to use a soldering paste such as 8,fluxite10 which is sold in a tin1 and can be kept handy and applied to the work with a sliver of wood4 8,tinol0 is a paste flux in combination with a solder4 ,preparing ,zinc ,chloride 78,killed ,spirit074--,make this flux at home from finely snipped new sheet-zinc and pure hydrochloric or muriatic acid4 7,this is sufficiently cheap at any working druggist's stores1 and infinitely preferable to the contaminated oil-shop quality known as 8spirits of salt407 ,stand the acid outdoors in a stoneware crock1 add the zinc cuttings a few at a time at first1 and when the first violent ebullition moderates1 put in the rest4 ,be sure to provide an excess of metallic zinc1 observing that a quantity remains undissolved after all chemical action ceases4 ,leave the metal in the liquor for twelve hours 7covering the crock with a pane of glass71 then decant and filter into a wide-mouth glass jar of handy size4 ,do not add water to the concentrated zinc chloride solution2 dilution is sometimes recommended1 but should never be done2 the heavy1 slightly syrupy1 water-bright liquor should be used as it is4 ,the alleged 8cleaning0 qualities of this chloride can scarcely be admitted to exist1 and its principal function is to shield the surfaces of the work from oxidation2 this it fulfils by the formation of a viscid glaze on the heated metal when the salt reaches its anhydrous 7waterless7 condition by evaporation4 ,the addition of water to the flux1 therefore1 only uselessly prolongs the period occupied by evaporation1 and wastes heat4 ,always remove all trace of flux from finished work1 first by soaking in water1 and afterwards by washing with soda1 soap1 and water4 ,otherwise1 there is the risk of the work being corroded4 ,special 8soldering solutions10 obtainable ready prepared1 should not be used in preference to zinc chloride made as before explained or to the well-known paste fluxes4 ,applying the ,flux4--,a short heavy bottle about #c in4 or #d in4 high is best for bench use as a flux container4 ,it should be particularly noted that soldering and soldering tackle should be kept as far away from other work 7and iron and steel goods and tools7 as possible4 ,a pointed wooden stick is not a good tool for applying killed spirit1 because the acid acts on the wood1 which becomes unpleasant to handle1 and the liquid does not leave the wood readily enough to place the right quantity on the exact spot to be soldered4 ,a galvanised iron wire is better4 ,another good tool is a thin steel or iron 8spit10 about #ab in4 long1 and a steel knitting-needle is also excellent4 ,should a brush be preferred1 take a few hairs from a broom1 place them in one end of a thin metal tube1 and then flatten the end with a blow from a hammer4 ,a brush made by hammering the ends of a short length of cane until the fibres are like bristles is frequently used for the purpose1 the handle end being soaked in molten wax before using the cane brush the first time4 ,illustration3 ,fig4 #a4--,wire for ,applying ,flux ,a convenient method of applying liquid flux is to have a bottle with a screw cap sprinkling top such as is often used for perfumes1 and to push a length of thick galvanised iron wire through the orifice in the stopper1 leaving about #a-a_/b in4 projecting above4 ,the lower end should just reach the bottom of the bottle1 and may be flattened and pointed4 ,the lead nipple is squeezed round the wire to hold it firmly1 and the projecting end bent into a ring to form a handle1 as shown in ,fig4 #a4 ,the cork part should be thinned a little to render it an easy fit in the bottle neck4 ,the flux can be quickly applied with the wire exactly where it is wanted1 and in very small quantity2 for a long seam the wire can be run along with one dip in the solution4 ,the fingers need not be brought into contact with the flux2 the cork will not go soft and will not sink down owing to the lead flange supporting it4 ,flux ,used on ,food ,containers4--,killed spirits is objectionable as a flux for soldering vessels intended to contain food of any kind4 ,not only is this flux a poison1 but it is liable to produce subsequent rusting wherever used unless all traces of it are thoroughly removed immediately after soldering4 ,a good non-poisonous flux suitable for tin boxes may be made by dissolving resin in oil4 ,place a quantity of powdered resin in an iron vessel1 add colza1 olive1 or any similar oil1 and apply gentle heat1 meanwhile stirring it until the resin is dissolved4 ,dissolve as much resin in the oil as possible without making the flux too thick 7when cold7 to apply with a brush4 ,one or two small experiments will soon decide the required proportions4 ,the resin is really the base of the flux2 but the oil is added to facilitate its application and removal before and after the soldering process4 ,,chapter ,,iv ,soft-soldering with the ,copper ,bit ,choice between ,blowpipe and ,bit4--,the method of heating depends on the size of the work1 or rather the area to be soldered1 and the conveniences at the command of the worker4 ,the soldering bit1 although so commonly used1 is not necessarily the best for the beginner to use for small work4 ,a blowpipe flame--from a bunsen burner or a spirit lamp--is far more convenient and neat1 and its effects can be applied and localised with the greatest precision1 down to the merest pin point of heat applied at a definite spot4 ,the bit is chiefly useful for long joints such as in tinplate work1 and for pieces bound together to which the bit is applied to heat up and melt solder between them4 ,but for work where the soldering area does not measure more than an inch or so 7and there is a vast amount of this kind71 the blowpipe flame is far preferable4 ,it must be admitted1 though1 that this is a matter in which some workmen might have two distinct opinions2 and1 as already remarked1 the bit is far more commonly used4 ,illustration3 ,fig4 #b4--,soldering ,bit ,illustration3 ,fig4 #c4--,pivoted ,soldering ,bit ,copper ,bits4--,the soldering bit or bolt 7miscalled an 8iron07 carries a pointed lump of copper at the end 7,fig4 #b71 riveted in1 or alternatively1 in small sizes1 screwed on to the shank4 ,some bits are pivoted 7see ,fig4 #c7 to enable them to point at various angles for dealing with difficult situations4 ,a home-made bit 7,figs4 #d and #e7 may be made by drilling and tapping a short length of #a-a_/b-;in4 or #b-;in4 square copper to receive the screwed end of a rod of #e_/af-;in4 iron1 the copper being afterwards heated and drawn to a point or to a blunt edge as preferred4 ,this forms a good bit for most ordinary purposes4 ,an axe-head or hatchet bit is shown in ,fig4 #f2 the copper bolt is riveted in the eye of the iron rod1 the bit1 however1 being free to revolve1 as this is essential when making joints in heavy lead pipe1 for which purpose it is principally used4 ,fig4 #e represents a bit which is a combination and modification of the two others1 and it is largely used for the internal soldering of bottoms of large drums1 milk churns1 etc41 where great local heat is required4 ,illustration3 ,fig4 #d4--;,home-made ,soldering ,bit ,illustration3 ,fig4 #e4--;,bit for ,internal ,soldering1 etc4 ,illustration3 ,fig4 #f4--;,hatchet ,soldering ,bit ,as to the size of bit required1 for ordinary small work the straight type should not be less than #h oz4 or #aj oz4 7weight of the actual copper74 ,two bits are very useful in doing a large job1 as the work can then be arranged to progress continuously1 one bit heating while the other is in use4 ,a bit suitable for quite light work can be easily made by drilling and tapping a piece of copper1 say #a_/b in4 by #a_/b in4 by #a-a_/b in4 long1 either in the end or in the side1 for a #c_/af-;in4 steel rod #ab in4 long1 a handle being then fitted at the other end4 ,in the 8,tinol0 telescopic soldering bit for amateurs' use1 the handle is in three parts3 7a7 the actual wooden handle bushed with metal1 and provided with a set-screw shaped like a screw eye1 and therefore easily turned2 7b7 a steel tube which telescopes into the first part1 and which is also provided with a set-screw2 and 7c7 a short rod1 having at one end a hatchet-shaped copper bit4 ,the extreme length of the tool is #ab in41 and the length1 when the parts are telescoped together1 is about #e in4 ,the 8,fluxite0 bit is larger and heavier4 ,it has a hollow cast-iron handle1 perforated to dissipate the heat1 threaded internally at one end to receive the screwed end of the iron stem1 only #e in4 or so in length1 which at the other end screws into an adapter or holder which1 in turn1 receives the screwed end of the copper bolt1 itself about #d in4 long4 ,the bit is taken to pieces in a few moments1 and is quite a workmanlike tool4 ,illustration3 ,fig4 #g4--,spirit-heated ,bit ,spirit-,heated ,soldering ,bits4--,bits heated by benzoline or spirit may be made with a small barrel-shaped reservoir which also forms the handle4 ,one end of the reservoir is fitted with a filling cap1 and from the opposite end protrudes the tube carrying the burner4 ,to the tube end of the reservoir an iron clip is attached1 and this secures an iron bar which stands out over the burner head4 ,at the end of this bar the copper bit is attached and held either vertically or horizontally in the flame4 ,tool merchants' catalogues show a variety of such implements4 ,fig4 #g illustrates one of the most elaborate of them all1 the weight complete being #b-a_/d lb4 ,it has a polished brass container ,a1 of #a_/e pint capacity--sufficient for #de to #fj minutes1 whence the benzoline flows to the burner ,b1 the flame from which heats the copper bit ,c4 ,this bit may be of any of the regular shapes1 and weighs about #a_/b lb4 ,the position shown is that for heating the bit preparatory to soldering4 ,the tray ,d catches any drips that might occur at starting1 ,e is the stand1 ,f the filler cap1 ,g is the regulating handle1 and ,h is the clamp that holds the bit in place4 ,illustration3 ,fig4 #h4--;,bit attached to ,blow-lamp ,illustration3 ,fig4 #i4--;,gas-heated ,bit ,a writer in ,popular ,mechanics has stated that the ordinary blow-lamp1 with the burner end equipped with a copper bolt 7see ,fig4 #h71 makes an excellent soldering device4 ,the point can be easily kept at the proper heat1 and there will be no want for hot coppers4 ,the end of the burner is threaded on the outside1 and a hole is drilled in the copper point and threaded to match4 ,small holes are drilled in the copper in the same manner as in the burner1 to make vents for the flame4 ,gas-heated ,bits4--,these are largely used in factories1 and are cleanly1 expeditious1 safe1 and convenient4 ,the type shown by ,fig4 #i is very handy1 and the illustration and description are due to ,f4 ,x4 ,sommers1 ,jun41 in the ,american ,machinist4 ,a mixture of air and gas enters the pipe at about #aj lb4 pressure1 or enough to give a hot1 blue flame4 ,the part ,a is of cast-iron1 which1 on experiment1 has been found to last longer without corroding than steel1 although copper would be better4 ,the soldering bolt ,b was made of steel because it kept the correct shape point much longer than cast-iron or copper1 although the latter metal is better for transmitting the heat4 ,the point should be tinned before using4 ,this form of soldering head is being used on automatic can-soldering machines1 and does the work effectively4 ,it also saves gas4 ,it will heat to the correct temperature in about #a-a_/b minutes4 ,illustration3 ,fig4 #aj4--;,gas-heated ,bit complete ,illustration3 ,fig4 #aa4--;,air ,inlets in ,end of ,air ,chamber ,illustration3 ,fig4 #ab4--,section through ,air ,chamber and ,gas-reducing ,valve ,illustration3 ,fig4 #ac4--;,details of ,cones or ,needles ,a gas-heated bit invented by ,w4 ,g4 ,ryan is shown in ,figs4 #aj to #ac4 ,the actual bit ,a is held in a steel sheath ,b having a space underneath the bit to allow the gas to pass4 ,the sheath has a row of holes on each side to allow the gas to come through1 the flame enveloping the bit when in use4 ,the gas1 supplied through a flexible tube1 passes through the tube that forms the handle1 at the end of which is a small chamber ,c to admit air1 which mixes with the gas to cause it to burn atmospherically1 the supply of gas passing through a small cone valve ,d and thence through the air chamber4 ,in the air-inlet holes ,e at the end of the air chamber are fitted small cones ,f to regulate the quantity of air4 ,all the cones1 including the gas-valve cone1 are connected rigidly together1 so that when cutting down the gas supply temporarily1 the air supply is automatically reduced1 and the gas flame remains in being1 although its size is much reduced4 ,it has been found that1 in some gas-heated bits1 the cutting down of the gas seriously interferes with the proportion of the gas and air mixture1 resulting in a back-fire4 ,the device here described has been invented especially to obviate that trouble4 ,to reduce the gas supply and1 with it1 the air supply also1 all that is necessary is a slight forward movement of the fitting to which the cones or needles are attached4 ,the copper bit is kept in position by the sheath or clip1 the small bolt in which can be taken out in a moment when special attention to the bit becomes necessary4 ,the connection to the flexible gas tubing is at ,g1 while ,h indicates a guide and stuffing box for the gas-valve cone or needle4 ,illustration3 ,fig4 #ad4--;,gas-stove for ,heating ,bits ,stoves for ,heating ,soldering ,bits4--,although a copper bit may be heated in any fire1 it is better to avoid the dirt1 smoke and tarry stickiness which are often present in a coal fire4 ,in the absence of gas1 a bright1 clear coke fire or a charcoal fire should be used whenever available4 ,portable oil stoves of the wickless type can also be employed1 but the ideal fuel is gas1 which may be regulated at will to give a uniform temperature4 ,two gas-stoves specially constructed for copper bits are shown by ,figs4 #ad and #ae4 ,illustration3 ,fig4 #ae4--;,gas-stove for ,heating ,bits ,tinning a ,bit4--,before a bit can be used1 it must be 8tinned10 that is1 coated with solder in a smooth complete covering1 for which purpose--by one method1 not the best1 but the most general--the end is heated to a dull red1 rubbed quickly with the file on the facets1 dipped in killed spirit or 8fluxite10 or rubbed against a piece of sal-ammoniac1 and then applied to a stick or lump of solder1 the facets being quickly wiped or rubbed on a piece of tinplate so as to spread the solder evenly4 ,when properly done1 the nose of the bit is coated with a smooth film of solder4 ,this must always remain so1 or the bit will not act1 and when it is honeycombed1 or the 8tinning0 is present in patches1 it must be re-tinned4 ,a bit must never be raised to a red heat sufficient to melt the tinning4 ,the bit does not operate well at such a heat1 because its contact makes solder too fluid and apt to run too quickly4 ,when dipping a hot bit1 prepared for tinning1 into killed spirit1 a sharp pop1 without smoke or spluttering1 denotes the right temperature4 ,if1 on withdrawing the bit1 it is damp and still unclean1 it had not been heated sufficiently4 ,another method of tinning may be mentioned4 ,into a small and clean tin box 7a #b-oz4 tobacco tin about #c_/d in4 deep7 put some scraps of solder and powdered resin4 ,heat the bit to a very dull red1 quickly file up clean on one side of the point1 and then plunge into the solder and resin and rub about2 it will at once take on a coat of the alloy4 ,a second side of the bit may be tinned by then repeating the operation1 re-heating if necessary4 ,the bottom of the box should be covered with solder1 which adheres easily enough1 with a film of resin on top4 ,it is probably most convenient to tin the under side and the left-hand working face of the bit4 8,tinol0 could be used in this way without admixture with anything4 ,still another method is to use a firebrick having a hollow in which the solder and resin are placed2 but the tin box plan is thought to be better4 ,undoubtedly the best method of tinning a bit is that in use by the plumber who well knows the invaluable qualities of sal-ammoniac 7ammonium chloride7 for the purpose4 ,he has no wish to squander energy on those vigorous rubbings of the bit--on paving-stone1 bath brick1 tinplate1 etc4 etc41 and he believes that the habit of dipping the bit into zinc chloride is both slovenly and wasteful1 for not only is this corrosive stuff sprayed about broadcast1 but the remainder is soon rendered unfit for its purpose by contamination with copper chloride and dirt from the fire4 ,the outlay of a few halfpence on a sizable slab of sal-ammoniac will keep the bit in the best condition for years1 and save hours of superfluous labour4 ,commercial sal-ammoniac is obtainable in large1 rugged crystals of a tough1 fibrous texture4 ,a piece weighing upwards of #a_/d lb4 can be trimmed to a roughly rectangular slab1 a few inches long and wide and about #a in4 thick2 and a cavity should be scooped in one of the flat sides to accommodate the bit4 ,illustration3 ,fig4 #af4--,tinning ,bit in ,sal-ammoniac ,block ,let the bit-faces be made shapely and filed bright and the tool thoroughly heated in a clean fire1 removed1 flicked free of ash1 and then held down firmly in the cavity of the sal-ammoniac block 7see ,fig4 #af74 ,profuse white fumes will arise1 and the surface of the salt will fuse4 ,bear heavily on each facet in turn1 and then melt a few beads of solder into the cavity along with the bit1 and the latter will become brightly tinned in a moment or so4 ,the bit should be applied to the 8ammonia block0 every few heats1 or as required1 as the work progresses1 and flicked with a tuft of dampened cotton-waste4 ,the sal-ammoniac has one great disadvantage--it is deliquescent 7collecting moisture from a damp atmosphere71 and its near proximity to most metals oxidises and corrodes them4 ,iron and steel1 particularly1 it rusts rapidly and deeply4 ,therefore the tools 7saw and chisel7 used to shape the block must be washed1 dried1 warmed1 and greased before they are laid by1 and the waste fragments must be carefully swept up and disposed of4 ,the block itself must always be kept apart from tools4 ,plumbers enclose it in a sheet-lead box wrapped in a greasy rag2 amateurs may store it on a dry shelf1 parcelled in waxed paper secured by a rubber band1 or in a length of motor-tyre inner tube1 rolled up4 ,simple ,soldering4--,scrupulous cleanliness in everything connected with the process of soldering is essential to success4 ,the ordinary procedure in making a joint is to clean the surfaces first by filing or scraping with a scraper or a knife or a plumber's shave-hook 7,fig4 #ag74 ,in some cases1 dirty metal is cleansed with dilute hydrochloric acid4 ,with or without preliminary heating of the work1 flux is then applied to the joint1 and the heated bit is held in one hand and a stick of solder in the other1 and the stick drawn along the joint while the bit touches it 7or 8drops0 of solder may be transferred to the work by means of the bit74 ,this will cause a line of molten solder to run1 and some skill and care are necessary to get just the right amount of solder without wasting it and allowing it to spread in a lumpy fashion beyond the necessary area4 ,the bit is next worked up and down the joint to spread the solder1 and by the transmitted heat to make it thoroughly penetrate the joint4 ,this is an outline of the process1 and there is a number of points requiring special instruction or a few words of caution4 ,illustration3 ,fig4 #ag4--,shave-hook ,note that the work must be filed1 scraped1 or otherwise mechanically cleaned1 and then chemically cleaned by coating with the flux just where the soldering is required4 ,in heating the copper bit do not let it reach even a dull red heat4 ,lightly dip it into the flux to clean the point2 then1 with a small button or blob of solder resting on the work1 place the bit momentarily upon it to cause the solder to flow1 and draw the bit where the solder is required4 ,many beginners try to draw along the solder with an insufficiently heated bit4 ,the result is a series of lumps--8putting it on with a trowel10 as it is sometimes termed4 ,a good joint cannot be made this way1 however much solder may be used4 ,some beginners fly to the other extreme1 and try to make a neat job with a red-hot bit1 which results in the solder assuming a sandy appearance and in the work being discoloured4 ,others try to solder uphill--that is1 they hold or place the work in such a way as to cause the solder to flow away from where it is required4 ,the correct method is to solder downhill by tilting or inclining the work1 so that the solder will always collect around and travel with the point of the bit4 ,this1 besides facilitating the work1 makes a strong joint1 and imparts a clean and neat appearance to the job4 ,illustration3 ,figs4 #ah and #ai4--;,incorrect and ,correct ,methods of ,holding ,bit ,a common mistake is to hold the bit in a cramped and awkward way1 as in ,fig4 #ah1 the hand being twisted under the handle1 the thumb being brought to the top1 and the elbow forced to the side4 ,the correct positions of arm and fingers are shown in ,fig4 #ai2 the elbow is held well out from the body1 and the thumb is placed directly under the handle of the bit1 forming a fulcrum over which the bit may be slightly raised or depressed at will4 ,this is all-important when soldering very fusible metals such as pewter1 tin1 etc41 on which the weight of the copper bit should never be allowed to rest1 as otherwise a hole will suddenly be made in the work4 ,the whole weight of the bit should be supported and balanced on the thumb by the downward pressure of that part of the hand close to the little finger4 ,the worker should not for a moment lose control of the copper bit1 and control is always assured when the thumb is underneath the handle4 ,there is but little strength in a butt joint with the edges of the metal only just touching--that is1 without a lap2 to take the example of a small cylinder1 the body seam should have at least a #a_/d-;in4 lap4 ,fig4 #bj represents an example of internal grooved seam soldering1 which may be executed in the following way3--,after applying the flux1 place a small button of solder inside the cylinder on the seam1 rest the bit momentarily on the solder to melt it1 and then draw it gently along the seam4 ,the cylinder should be slightly tilted to allow of the solder travelling with the point of the bit4 ,the hand should avoid touching any part of the work that comes directly into contact with the copper bit1 as otherwise the hand would be badly burned4 ,illustration3 ,fig4 #bj4--,soldering ,internal ,grooved ,seam ,illustration3 ,fig4 #ba4--,soldering on ,can ,bottom ,internally ,the method of internally soldering the bottom on a canister1 etc41 is shown in ,fig4 #ba4 ,the bottom is held in position by gently pressing it against 7but not placing it on7 the bench during the soldering process1 while the tilt of the canister and the position of the bit cause the solder to travel with the bit4 ,in soldering all such articles1 the soldering should be done with one sweep of the bit1 the left hand meanwhile making the necessary revolution4 ,this saves time and solder1 and avoids the unsightly appearance of a series of starts and stops4 ,in work of a larger and more substantial nature1 as1 for example1 galvanised or tinned iron work1 the bottom of the article is first 8knocked up10 and then soldered internally4 ,fig4 #ba represents an example of internal soldering where the whole weight of the bit is shown resting on the molten solder inside2 this provides the local heat required to 8sweat0 the solder into the four thicknesses of metal which constitute the bottom seam2 and for this work the bottoming bit shown in ,fig4 #c is often used4 ,pewter1 lead1 zinc and tin--the latter should not be confused with tinplate--do not require sweating1 on account of their low fusibility1 and any attempt even to solder them with a very hot bit will probably end disastrously4 ,illustration3 ,fig4 #bb4--,soldering ,can ,externally ,fig4 #bb shows an example of external seam soldering4 ,the method there shown is invariably adopted for simple lap seams1 although grooved seams are similarly soldered4 ,a grooved seam1 however1 should preferably be soldered internally4 ,the position of the worker's elbow and thumb should be noted1 as should also the tilt of the cylinder 7more pronounced in this case than the other7 in order to secure the downflow of the solder4 ,sweating has already been mentioned4 ,it should be said that one of the easiest ways in which a beginner may make a reliable joint is to prepare both faces of the joint by fluxing and covering with a thin film of solder1 and then pressing the two parts together with the hot bit until the top part 8floats0 and then settles down4 ,the advantage of this way is that one can be sure of perfect application of the solder to the joint faces1 since each is dealt with first and thoroughly coated1 with no faulty patches4 ,sweating is also done in the flame of a bunsen burner or blowpipe1 as explained later4 ,reinforced and ,filled-in ,soldered ,joints4--,the bottoms of square or cylindrical vessels should1 preferably1 be soldered from the inside1 and 8buttons0 of solder may be melted to assume a stout triangular-shape stud in the corners of the square vessels4 ,a tinned rivet is sometimes riveted or just placed in a corner1 and sufficient solder floated over it to strengthen the corner4 ,solder is always liable to run through an improperly closed seam at the corner when external soldering is resorted to2 but in cases where this is the only practical method1 a tinned rivet may be inserted from the outside1 and then soldered over4 ,it sometimes happens that two 8raw0 edges require soldering together without a lap4 ,where a strong joint is required a good plan is to place a length of tinned wire over both edges and solder the lot together4 ,in addition to strengthening the joint1 the wire considerably improves the general appearance4 ,a simpler joint may be made by 8skimming0 the solder over with a copper bit heated only just sufficiently to melt the solder4 ,the quick and skilful touch is required to perform this operation satisfactorily2 but a little practice will soon bring the necessary proficiency4 ,the idea is to 8draw0 the solder across the joint quickly1 before it has time to run through4 ,this method is useful when soldering thin metal goods of a lower degree of fusibility than that of the solder employed4 ,no preparation for filling cracks previous to soldering can be recommended1 beyond such small pieces of metal that may be afterwards soldered over and effectively hidden4 ,it is much better to endeavour to produce work of such quality that this expedient is altogether unnecessary4 ,soldering ,heavy ,milk ,churns4--,when soldering the bottom rims on large milk churns1 sufficient heat cannot be maintained with only one soldering bit4 ,at least two heavy bits are required1 so that one may be getting hot while the other is in use4 ,the rims are usually tinned before being fixed by first pickling them in dilute hydrochloric acid1 washing1 and then dipping in a bath of molten tin4 ,when repairing and resoldering the rims1 remove all dirt and rust with a file1 use a few brushfuls of raw spirits further to assist the cleaning process1 then wash with clean water and solder in the usual way1 using killed spirits as a flux4 ,soldering ,hole in ,enamelled ,ware4--,first scrape or file away the enamel quite clear all round the hole1 apply a little raw spirit to the surface of the iron1 and coat it with solder in the usual manner4 ,then cut out a tin disc large enough to cover the hole1 and solder this in1 using killed spirit as the flux4 ,soldering ,leaded ,lights4--,for soldering the calmes of a lead-light window1 the calmes having been fitted properly together1 shave a small round dot at the point of junction1 sprinkle a little powdered resin on the shaving1 and with a copper bit or with a glazier's iron having a tinned face1 melt a small piece of tinman's ordinary solder on the shaved part so that it tins to the lead and forms a round button4 ,soldering ,catch on ,gun-barrel4--,in soldering a catch on a gun barrel it will first be necessary to tin both barrel and catch1 and then to wire them together1 in addition binding the barrels for some distance from each side of the catch1 making the ribs secure with wedges4 ,to melt the solder1 use heaters2 these are generally made of copper with iron handles2 or iron rods can be used1 the ends being made red hot and inserted in the barrels4 ,cut some small slips of thin solder and place them on each side of the catch1 using powdered resin4 ,as soon as the solder melts1 remove the heaters and cool the barrels4 ,illustration3 ,fig4 #bc4--,mouth ,blowpipe ,illustration3 ,fig4 #bd4--;,black's ,mouth ,blowpipe ,illustration3 ,fig4 #be4--;,fletcher's ,mouth ,blowpipe ,illustration3 ,fig4 #bf4--,section through ,blowpipe ,flame ,,chapter ,v ,soft-soldering with ,blowpipe or ,bunsen ,burner ,the ,mouth ,blowpipe4--,although soft-soldering is usually associated with the use of a copper bit1 quite a number of jobs can be done without one1 using instead a bunsen burner or1 more generally1 a mouth blowpipe1 which is an inexpensive appliance1 useful for both hard and soft soldering1 and with either gas1 candle1 or a methylated-spirit flame4 ,three shapes of mouth blowpipe are shown in ,figs4 #bc to #be4 ,in a blowpipe flame there are three cones1 ,x1 ,y1 ,z 7,fig4 #bf74 ,x is a non-luminous cone1 consisting of a mixture of atmospheric air and unburnt combustible gases 7each with a low temperature72 ,y is a luminous cone1 composed of burning gases 7carbon and carbonic acid being in excess72 and ,z is a cone the oxygen in which renders it less luminous and free from combustible materials1 its temperature being exceptionally high1 especially where the cone comes in contact with the point of the cone ,y4 ,because of its properties1 ,z is termed the oxidising or outer flame1 whilst ,y is known as the inner or reducing flame1 because when it is applied to some easily reducible substance--say1 lead oxide--the oxygen in the substance heated mingles with the unburnt carbon in the cone of the flame and produces carbonic oxide1 the lead being thus separated or reduced4 ,the blowpipe flame is one of intense heat1 even that produced by blowing a common candle being capable of melting metallic fragments when they are supported on a bed of charcoal4 ,the pointed flame gives the greatest heat1 and this can be produced simply by increasing or decreasing the space between the flame and the article to be soldered or the metal to be melted4 ,the particular advantage of a blowpipe is that it gives a fierce heat at a very localised area1 beyond which the solder does not run1 and it enables spots to be soldered1 or parts to be unsoldered1 adjusted and re-soldered without allowing heat to stray and cause trouble at other places4 ,a useful little addition to the ordinary blowpipe is a small washer soldered on near the mouth end 7see ,fig4 #bc71 the object of this being to raise this part off the bench and so keep it from contamination with dirt1 filings1 etc41 which are unpleasant to the lips4 ,sometimes the washer is made elliptical and slightly concave to fit the lips1 so that it forms a convenient stop or steady when the blowpipe is held between the teeth without help from either hand4 ,bunsen ,burner1 ,spirit ,lamps1 etc4--,the bunsen burner is1 of course1 the most convenient device for heating 7when the bit is not in question72 but failing a gas supply1 a spirit-lamp must be employed4 ,this is a small glass bottle with wick1 methylated spirit being used4 ,plumbers and gasfitters make use of metal tubular lamps fed with spirit poured on cotton-wool1 and having a blowpipe tube attached and coupled up to the lips with a rubber tube2 they also use wax tapers4 ,illustration3 ,fig4 #bg4--;,home-made ,spirit-lamp ,illustration3 ,fig4 #bh4--;,another ,home-made ,spirit-lamp ,a methylated wick lamp may be easily made out of a small 8self-opening0 canister1 as shown in ,fig4 #bg4 ,the holes near the top increase the efficiency of the flame4 ,another spirit soldering-lamp is shown by ,fig4 #bh4 ,the container for the spirit can be made about #c in4 in diameter by about #a-a_/b in4 deep1 with a handle soldered on4 ,a glance at the illustration will explain the burner4 ,an outer wick surrounds a piece of tube1 which itself contains another wick4 ,the spirit in the inner tube is vaporised by the heat from the burner when the outside wick is lit4 ,the spirit vapour issues from a #a_/cb-;in4 hole at ,a4 ,at ,b a ring is slipped over the outer wick1 holding it to the central tube4 ,by lifting the central tube the height of the vaporising flame can be adjusted4 ,the vaporising tube is a piece of #c_/h-;in4 brass tube with a #c_/h-;in4 gas cap screwed on the end1 or a brass disc can be brazed in4 ,the total cost should not exceed sixpence4 ,illustration3 ,fig4 #bi4--,swivelling ,gas-burner for ,bench ,soldering ,bench ,blowpipes4--,the best form of gas bracket for bench use is one having a horizontal swivelling arm1 and screwed to the bench by a flange1 as shown in ,fig4 #bi4 ,the swivelling head is also a cock1 which shuts off the gas when the jet arm is pushed over at right angles to the edge of the bench1 as indicated1 and the gas is connected by an iron or compo pipe under the bench4 ,a second gas tap should be arranged in the supply to regulate the amount of gas1 and for reasons of safety4 ,a simple device 7see ,fig4 #cj7 may be made by anyone1 and connected to a rubber-pipe connecting head on the gas bracket supplying light to the bench and workshop4 ,a design of gas blowpipe which leaves one hand free is shown by ,fig4 #ca4 ,this enables the worker to apply the solder to the work 7holding the end of a strip against it71 after it has been brought to the melting heat of the solder4 ,the blowpipe is arranged so that it can be held in the hand or dropped into a hole in the bench4 ,tapers4--,tapers for a blowpipe flame are made by untwisting cotton rope until the threads of the individual strands are straight4 ,these are then dipped in melted wax made by melting two wax candles over a gas stove in a jam jar4 ,they are repeatedly dipped until sufficient thickness of wax is obtained4 ,the wax should be just sufficiently hot to keep melted4 ,illustration3 ,fig4 #cj4--,simple ,bench ,burner ,illustration3 ,fig4 #ca4--;,gas ,blowpipe for ,bench ,catching-tray for ,bunsen ,burner4--,the blowpipe is not essential for some kinds of work1 such as when the job can be held wholly in the flame without causing any damage4 ,when solder is being melted to drop on to a surface1 the plain bunsen or atmospheric flame is also sufficient1 though in this case it is well to tilt the burner over so as to prevent the solder dropping down the tube4 ,an elbow fitted on the top of the tube is handy in this connection1 to deflect the flame at an angle1 and ,figs4 #cb and #cc show this1 with the addition of a tray to catch the dripping solder which otherwise would splash on the bench and cause untidiness4 ,the tray is riveted to a strip of brass bent round to slip over the outside of the elbow1 and a small pin riveted into the tube prevents the tray from falling down4 ,illustration3 ,fig4 #cd4--,section through ,blowlamp for ,soldering1 ,brazing1 etc4 ,illustration3 ,figs4 #cb and #cc4--;,bunsen ,burner and ,solder-catching ,tray ,blow ,lamps4--,a soldering lamp is used sometimes in the place of a blowpipe1 and it should combine perfect security with compactness and portability4 ,tool merchants' catalogues show a number of styles4 ,in the lamp shown by ,fig4 #cd1 benzoline is burnt4 ,when the lamp is in use and the body of it is very hot1 the inside pressure does not exceed three-fifths of an atmosphere1 whether the regulator ,r is open or almost closed4 ,thus the danger of explosion1 which is such a drawback to some of the lamps that use ordinary paraffin1 is avoided4 ,the upper parts of the lamp are subjected to great heat and therefore are packed with asbestos1 which serves as a filter and stops any impurity in the benzoline from getting to the burner4 ,the flame can be lowered to a glimmer when not actually in use1 thus saving the trouble of relighting4 ,when the lamp is to be used1 the regulator ,r is screwed up tight2 and care must be taken to ascertain1 from time to time1 that the burner or nipple ,c is open and perfectly clean4 ,if this becomes obstructed1 it can be cleaned by unscrewing the tube ,t and passing a fine steel wire through the hole4 ,the lamp should be completely filled with benzoline every time it is to be used4 ,a little methylated spirits is poured into the basin ,a1 and set alight4 ,when the apparatus has become slightly warm1 the regulator is opened gradually4 ,to extinguish the flame1 the regulator must be screwed up tight4 ,if any escape is observed round the screw of the regulator1 the square ,p should be screwed up with the key supplied by the makers1 so as to tighten the asbestos packing4 ,the lamp above described is only one of a great number of such appliances1 but it is fairly typical of them all4 ,the difference between a solderer's and a brazer's blowlamp is merely one of size and power4 ,illustration3 ,fig4 #ce4--,soldering ,lading-can handle ,illustration3 ,fig4 #cf4--,soldering ,lug to ,lamp ,bottom ,how to ,operate a ,mouth ,blowpipe4--,the operation of using the mouth blowpipe does not consist in blowing intermittent and strong blasts with the lungs1 as this would soon exhaust the wind power4 ,for very light jobs1 however1 this method is sometimes adopted2 but once the proper way is discovered1 the user naturally falls into the use of this method4 ,the proper way to keep a continuous blast is to breathe naturally through the nose1 and at the same time keep the cheeks distended by forcing the air at sufficient pressure from the lungs4 ,the cheeks naturally resist the pressure1 and force the air through the blowpipe4 ,the operation requires some practice and a clear nose passage4 ,there is practically no limit to the time a continuous blast can be kept up4 ,the blowpipe flame is produced by holding the blast end of the blowpipe just above the wick of the taper and touching the flame2 the blast then causes a long blue flame to project4 ,this flame is hottest at the tip1 which is slightly brown4 ,typical ,blowpipe ,jobs4--,some of the photographic reproductions in this chapter show the methods of soldering comparatively light and heavy articles4 ,fig4 #ce shows a lading-can handle being resoldered4 ,as it had broken away1 the old solder remained1 and the joint did not need cleaning4 ,it is dabbed with the killed-spirit brush1 and a small piece of solder put near the joint4 ,the flame is first played on the parts away from the solder to get them to the requisite heat1 and as the heat reaches the solder it melts1 and flows where required4 ,where the solder should be the thickest1 that part of the joint is inclined downwards4 ,a job needing very much heat1 and therefore a continuous blast for some time1 is shown by ,fig4 #cf4 ,a lug is shown being soldered to a heavy brass lamp bottom4 ,before putting the lug in position the parts of the joints have to be tinned4 ,this consists of applying a film of solder4 ,in this case the heat is applied to the lamp bottom for several minutes1 and without loss of time the part where the lug fits is cleaned with a fine file1 the spirit brush dabbed on a piece of solder1 put in position1 and the flame again applied4 ,the solder almost immediately flows over the cleaned portion2 if it does not flow as required1 the flame is played on the solder and lamp bottom1 a dab with the spirit brush helping matters4 ,the lug1 which should have been previously tinned1 is placed in position on the lamp bottom1 and with a slight application of the flame1 the solder flows and unites the parts firmly together4 ,it should be particularly noted that1 when uniting light articles to heavy ones1 the light ones should be tinned first1 and secured to the heavier article whilst the latter is still hot4 ,illustration3 ,fig4 #cg4--,soldering ,wires of ,vegetable ,masher ,illustration3 ,fig4 #ch4--;,holder for ,applying and ,adjusting ,solder ,fig4 #cg shows the wires of a vegetable masher being soldered4 ,there is nothing special about the job1 except that the solder cannot be placed on the joint4 ,to effect this a piece of tin 7,fig4 #ch7 is indented at one end1 and a small hole made in the centre of the depression4 ,the bead of solder is placed in this depression1 and held over the joint to be soldered2 the flame is then played on the joint and on the solder which flows through the hole4 ,illustration3 ,fig4 #ci4--;,brushing ,solder around ,dial ,ring ,illustration3 ,fig4 #dj4--,tinning ,dial ,ring ,figs4 #ci and #dj show the method of tinning a brass dial ring4 ,the ring is filed clean and placed on a piece of asbestos board1 the flame being applied until the ring is sufficiently hot all round4 ,a bead or two of solder is placed on1 and1 as they melt1 the solder is brushed round as shown in ,fig4 #ci with the spirit brush1 the flame being applied at intervals to aid the flow4 ,illustration3 ,fig4 #da4--,re-soldering ,kettle ,spout ,re-soldering ,kettle ,spout4--,refixing a spout in a 8tinned0 wrought-iron or copper kettle4 ,the spout and that part of the kettle which comes in contact with it should first of all be filed bright and clean4 ,next place the spout in position1 apply killed spirits1 and hold it over a bunsen flame1 as in ,fig4 #da1 until sufficient of the strip solder is melted to flow around and sweat through to make a strong sound joint4 ,should any difficulty be experienced in getting the solder to flow readily1 apply a little more flux4 ,soldering ,corroded ,metal4--,when the surface of metal to be soldered is badly corroded1 and it is difficult to obtain a clean1 bright surface preparatory to soldering1 it should be treated to a liberal application of raw spirits of salts 7hydrochloric acid71 which will soon remove the cause of the trouble1 but all traces of the acid should be washed away with clean water before attempting the soldering4 ,it is also a good plan in these cases to tin the surface by repeatedly rubbing it with a hot bit and solder1 together with plenty of killed spirits1 before proceeding with the actual soldering process4 ,soldering ,small ,work4--,when soldering two small awkward-shaped pieces together1 they can be held in position by pressing slightly into a piece of damp clay4 ,when the work has several soldered joints it can be buried in sand or covered with clay to confine the heat to the part being operated on4 ,although care should be taken to limit the solder to the area of the joint1 there are circumstances in many cases where it is difficult to prevent some of it from straying4 ,to clean this off1 resort may be had to the blowpipe1 applying the blast and quickly wiping the surface while the solder is in a molten state4 ,or it may be filed off while cold and finished with a scraper or a knife and emery-cloth4 ,or if there is only a thin film the knife or emery-cloth alone will suffice4 ,soldering ,pipe ,joints4--,most joints in lead1 tin and compo4 pipe are now preferably made by means of a blowlamp1 or with a mouth blowpipe1 strip-solder being used4 ,when making the joint1 heat the pipe in the immediate vicinity1 and1 dipping the solder in the flux1 stroke it around the pipe to form the joint4 ,in soldering block tin or compo4 pipe with a bit1 if this is too hot it will promptly melt the pipe4 ,this is also liable to happen with very thin zinc4 ,the only way to prevent this is to have the bit just hot enough to melt the solder1 and not to let it rest any length of time on the soft metal4 ,illustration3 ,figs4 #db and #dc4--,soldered ,branch ,joint on ,tin or ,compo4 ,pipe ,in making connections with soft pipe it is better to make use of brass couplings1 and these can be soldered more easily and safely by means of the blowpipe than with a bit4 ,first clean and tin both ends of the coupling1 and with the bit put a little ring of solder round about #a_/h in4 from the end1 as shown at ,d in ,fig4 #db4 ,next with a penknife cut a hole in the pipe ,b where the connection is wanted1 a neat fit for the end of the coupling tail ,a1 scraping the surface of the pipe all round the hole4 ,insert the coupling in the hole in a vertical position4 ,sprinkle a little powdered resin round the joint1 or smear it with fluxite4 ,using the flame of a spirit lamp or a candle and a mouth blowpipe1 heat the upper part of the coupling1 being careful not to allow the flame to come too near the soft pipe4 ,the solder will soon melt1 and run down into the joint 7see ,d in ,fig4 #dc71 when the flame must be instantly withdrawn4 ,the same proceeding can be adopted in soldering the other portion of the coupling into the connecting pipe4 ,if a vertical position is inconvenient for the coupling it can still be soldered in that position1 and afterwards twisted carefully into the desired position4 ,in ,figs4 #db and #dc1 ,c represents a wood plug for steadying the coupling tail4 ,illustration3 ,fig4 #dd4--,soldering ,birdcage ,wires ,soldering ,birdcage ,wires4--,for this job1 it is better to flatten out the solder to the thinness of brown paper and with a pair of scissors or shears to cut it into very narrow strips4 ,take little pieces about #a_/d in4 long1 and with the fingers pinch them round the wires just above the joints to be soldered4 ,touch each joint with a small quantity of killed spirit1 and apply the flame of a small blowlamp just underneath the joint2 this will cause the solder to run in the joint in an instant 7see ,fig4 #dd74 ,the flame is quite free from smoke1 and does not discolour the wire in the least1 as the solder will run long before the wire is red hot4 ,every joint may thus be neatly made4 ,with a thin piece of copper wire secured in a handle as illustrated1 the solder may be drawn any way desired to make special joints in awkward places1 where the point of an ordinary soldering bit could not be used4 ,sweating4--,in the preceding chapter it was shown how useful sweating is1 when accomplished with the help of the bit4 ,in blowpipe work1 also1 this method is of much utility1 particularly in delicate work where portions have to be joined up in very precise relations4 ,after tinning the joint faces the pieces are secured in accurate relationship with binding wire1 or by bolts or screws or other means1 or a soldering clamp is employed1 having jaws which clamp the pieces and enable them to be adjusted to the exact locations desired1 and the flame then brought to bear until the work is hot enough to cause the solder to run4 ,an example of the usefulness of sweating occurs in the making or repairing of metal name plates having superimposed brass1 copper1 or other metallic letters4 ,the plate having been flattened and polished and the letters cut out1 filed and finished1 the backs of the letters must be rendered chemically clean by careful scraping1 and are next 8tinned0 with soft solder4 ,the tinning may be done in several ways1 but the easiest is by the blowpipe1 using resin oil as flux4 ,each letter may be placed in succession on a lump of charcoal1 using plenty of the resin oil1 and applying the flame of the blowpipe to the surface while one hand holds the charcoal and the other the strip of solder4 ,to prepare the solder1 which is sold in sheets by the pound1 cut some strips #a_/c in4 wide4 ,take hold of one end #a in4 from the end1 and with a sharp knife scrape the surface1 drawing the knife edge downwards4 ,do not use the last #b in4 of the strip1 as the handling of this part makes it chemically unclean4 ,the greater part of the solder should be about the edges of the letters4 ,the next operation is to solder the letters to the brass plate4 ,as the brass plate also must be chemically clean1 the parts where the letters are to go should be lightly scraped4 ,having ruled parallel lines in order to get the letters in line1 lay each down in its proper place1 and draw a pencil line round it2 then with a scraper just remove the surface of the brass where the letters are to be soldered4 ,a thin piece of solder is now placed underneath each letter1 and each in turn is fixed in its place and secured with a loop of binding wire screwed up tight4 ,nothing now remains to be done but to apply the blowpipe flame and resin oil1 when the solder will run underneath the letters4 ,it is better to set the plate on some small lumps of charcoal4 ,when the letters appear to be set fast1 remove the plate and boil it in a solution of potash1 about #a_/b lb4 to #a-a_/b gal4 of water1 and clean in dry sawdust4 ,the resin oil may be made by dissolving resin in sweet oil by gentle heat1 until the oil will cause the solder to run4 ,,chapter ,,vi ,soldering ,aluminium ,it is well known to those accustomed to the art of soldering that there is no solder which operates with aluminium in the same way that ordinary solders operate with tinplate1 copper1 brass1 etc4 ,aluminium soldering presents so many difficulties that it has been thought desirable to devote a separate chapter to the subject4 ,there is more than one reason for the difficulty encountered4 ,aluminium does not alloy readily with solders at temperatures as low as other metals require2 and1 secondly1 aluminium alloys with lead solders only with great difficulty1 and with but a small proportion of lead at that4 ,consequently1 lead solders are not suitable for aluminium4 ,another and even more serious reason is in respect to the refractory oxide which forms at soldering temperatures1 and which is undoubtedly responsible for most of the trouble4 ,the soldering of aluminium is one of the most debated subjects in metal working4 ,almost as soon as aluminium was prepared on a large scale1 it was discovered that the ordinary solders and fluxes did not answer with it4 ,either pure tin or pure zinc will wet aluminium1 and can1 therefore1 be used as solder for it2 experience shows that the tin soon falls apart1 while zinc by itself is brittle and discolours badly4 ,the failure of tin is due to the fact that it forms with the aluminium an alloy that is decomposed by the action of the oxygen present in the air4 ,although aluminium is popularly supposed to be non-oxidisable1 really the surface is covered with a very thin film of oxide1 which prevents solder from alloying with the metal4 ,aluminium when heated rapidly oxidises4 ,it is customary to scrape the metal before and during the soldering2 and although some workers say that it is useless to scrape before soldering because oxidation immediately starts again1 it is obvious that a thin film is more easily penetrated than a thick one4 ,often it answers to scrape with the copper bit during the soldering1 previously rubbing off the oxide with emery cloth4 ,the work should1 if possible1 be backed with asbestos1 to keep up heat in the metal4 ,to discover whether the surface is thoroughly tinned1 wipe off lightly1 and the untinned parts will then soon become apparent4 ,if the oxide is not scraped off beforehand1 it will probably mix with the solder and form a scum1 which will make a neat flow difficult4 ,scum should be lightly removed with an old knife blade4 ,it is essential to 8tin0 every part to be joined1 as the solder will not take on any spot that has not been rubbed in some way1 unless previously coated4 ,solders for ,aluminium4--,hundreds of aluminium solders have been invented1 naturally all claimed to be strong and durable1 the alloys containing various metals1 such as aluminium1 antimony1 bismuth1 cadmium1 chromium1 copper1 lead1 manganese1 silver1 phosphor tin1 tin1 and zinc4 ,a table of the most approved aluminium solders is here given4 ,many of the best solders for aluminium contain a small proportion of phosphor tin4 ,a molten alloy containing phosphorus placed on aluminium tends to absorb oxygen from the impure film as well as the surrounding air4 ,,compositions ,,of ,,aluminium ,,solders ---------------------------------------- ------------- ,tin ,zinc ,sil- ,alu- ,cop-,bis-,phos- ,cad- ,lead ,anti- ver min- per muthphor mium mony ium ,tin ---------------------------------------- ------------- #gbe #be -- #ae -- -- #a -- -- -- #hj #bj -- -- -- -- -- -- -- -- #ig -- -- -- -- #c -- -- -- -- #bj -- #aj #gj -- -- -- -- -- -- #ij -- -- #aj -- -- -- -- -- -- #fe #bg #ege #bbe -- -- -- -- -- -- #cj #bj -- -- -- -- -- #ej -- -- #ii -- -- -- #a -- -- -- -- -- #ij -- -- -- #i #a -- -- -- -- #f #gge -- #cbe -- -- -- -- #cbe -- -- #ij -- #f #d -- -- -- -- -- -- #hj -- #ab #h -- -- -- -- -- -- #hj -- #bj -- -- -- -- -- -- -- #ij -- #e -- -- -- -- -- #e #hj #ag -- #bbe -- -- #ge -- -- -- #ge #bb -- #be -- -- #e -- -- -- #gj #be -- #c -- -- #b -- -- -- ---------------------------------------- ------------- ,in making the solders here given1 it is advisable to avoid loss of the more easily volatile of the metals by adopting the following precautions3 ,the aluminium is melted first1 the zinc is added in small pieces1 then tin in small pieces1 and lastly the phosphor tin4 ,inasmuch as zinc alloys with aluminium more readily than does any of the common metals1 solders that will readily 8tin0 aluminium generally contain zinc in varying proportions4 ,the solders found most satisfactory contain zinc1 tin1 aluminium1 and a very small proportion of phosphor tin2 but they do not run very freely or fuse so readily as the ordinary tin and lead solders1 and it is necessary to use a higher temperature1 so high1 in fact1 that difficulty is found in using these solders with a soldering bit1 and it is generally necessary to use a blowlamp4 ,while there is no solder that allows aluminium to be soldered with the facility and success experienced with other metals1 that of ,richard's is extensively used1 and seems to have given as good results as any4 ,it consists of the following ingredients3 ,tin #bi parts zinc #aa parts1 aluminium #a part1 and #e per cent4 phosphor tin #a part--practically the same as that given in the last line of the table4 ,this solder has withstood the test of time better than many of the patented solders1 and can be used in jointing aluminium to aluminium1 also aluminium to copper or brass1 and without the use of a flux4 ,in making the solder it is advisable to avoid loss of the more easily volatile of the metals4 ,the aluminium should be melted first1 then the zinc1 tin1 and phosphor tin in the order named4 ,when using phosphorus instead of phosphor tin in the making of aluminium solder1 it will first be necessary to incorporate it with the tin1 for which purpose take a length of #a-;in4 gas barrel1 attach a screwed cap at one end1 and close the opposite end with a tin 7not tin-plate7 plug4 ,remove the screwed cap1 and1 having carefully dried between blotting paper the proper proportion of phosphorus1 insert the latter in the tube and replace the cap4 ,now put the plugged end of the tube into the molten tin2 this will melt the plug of tin and so allow the phosphorus to come in contact with the molten metal4 ,the ingot of phosphor tin formed is afterwards alloyed with the other ingredients1 as already explained4 ,fluxes for ,aluminium4--,a large variety of fluxes have been tried with more or less success1 namely1 borax1 copper chloride1 lithium chloride1 paraffin resin1 sal-ammoniac1 stearin1 silver chloride1 tin chloride1 venetian turpentine1 tallow1 vaseline1 and zinc chloride4 ,stearin is undoubtedly the most reliable of them all1 but no flux is needed for solders containing phosphorus1 which is itself a flux4 ,the ,soldering ,bit4--,the average temperature required to make a satisfactory and thoroughly sweated joint in aluminium is from #fej ,f4 to #fhj ,f41 according to the size of the article4 ,a blowpipe or blowlamp will be of great value1 and is frequently preferable to a bit4 ,should a bit be used1 see that it is of aluminium or nickel instead of copper1 the point and the soldered joint being kept much cleaner whilst removing the film of oxide during the soldering operation4 ,another advantage is that the point or 8face0 of the bit can be 8tinned0 with the same flux as that which is used for the joint4 ,more care must be taken in the manipulation of the aluminium soldering bit owing to its lower melting temperature than the copper and nickel bits4 ,the ,process of ,soldering ,aluminium4--,the soldering of aluminium must be performed quickly to be satisfactory1 as the metal1 if not coated at the first attempt1 may be injuriously affected4 8,tinning0 the parts required to be soldered first is another important factor2 also the distance of the overlap of the joints should not exceed more than #a_/h in41 so as to allow the solder to flow thoroughly through2 it does not flow so readily as when soldering other metals4 ,in soldering large pieces1 where the ordinary overlap is not allowable1 and where a butt joint would be weak1 fit the pieces together as at ,a 7,fig4 #de74 ,illustration3 ,fig4 #de4--;,aluminium ,fitted ,together for ,soldering ,solder always flows towards the hottest point4 ,this tendency enables one to direct its course under the blowpipe or blowlamp flame4 ,a large flame should only be employed in 8heating0 up the part to be soldered on large and heavy work4 ,with a small pointed flame directly on the solder and the parts on which it rests1 the solder will flow quickly1 and leave a smooth1 even surface at completion4 ,some aluminium solders now on the market are so hard that it is necessary to heat them and the work to redness before they melt4 ,sheet aluminium is easily warped by heat1 and also contracts badly4 ,if the solder is too high in melting point1 the metal must also be brought to that point to cause proper union4 ,if a hole is being filled in1 the body of the metal on heating expands all round and partly closes the hole2 also both the solder and the patch whilst hot are slightly expanded4 ,in cooling1 the hole enlarges1 the patch contracts1 and the solder also contracts2 cracks result4 ,the body of the work1 if not exactly evenly made1 will warp1 which is fatal to engine and similar work4 ,by using a low-heat solder 7melting point1 about #gjj ,f47 these troubles should be avoided4 ,soldering ,aluminium to ,copper or ,brass4--,aluminium can be readily soldered to copper or brass with fine solder 7#b parts of tin and #a part of lead73 tin the metals1 using stearin as flux previous to making the required joint4 ,it is essential that both the 8tinning0 and soldering should be thoroughly done4 ,do not expect the solder to pull the joint together1 but see that the joint is kept under slight pressure until the solder is hard1 otherwise the joint will not be perfect4 ,many workmen refuse to place any reliance in such joints4 ,finally1 it seems very likely that1 at any rate as regards factory work1 the use of solder on aluminium objects will be wholly discarded in the future in favour of fusion welding or autogenous soldering1 in which process no alloy is interposed between the surfaces to be joined4 ,information on the subject is given towards the end of this book4 ,,chapter ,,vii ,wiping ,joints on ,lead ,pipes ,plumbers make joints in lead pipes with soft solder which1 by means of cloths1 they 8wipe0 to the shape shown by ,fig4 #dg4 ,figs4 #df and #dg show the difference between a copper-bit or blowpipe joint and a wiped joint4 ,plumbers' ,solder4--,as already stated1 coarse1 or plumbers' wiping solder1 is made in the proportion of #b of lead to #a of block tin4 ,care must be taken that the lead is quite pure and free from any other metal1 as zinc-adulterated solder will be difficult to use1 and joints made with it on service pipes will not be sound4 ,in melting up scrap lead for making solder1 only sheet lead should be used1 as the lead used in the manufacture of sheets is much purer and contains a greater proportion of pure pig lead4 ,the scraps must be quite dry2 a damp piece dropped into a pot of molten metal may cause a serious accident1 as the contents of the pot may be blown out4 ,to test the quality of solder when made1 heat it as for wiping a joint2 the correct temperature is determined by dropping a small piece of newspaper into the pot1 and if it quickly burns and catches alight the solder is right for using4 ,next pour a small quantity on to a cold but dry stone or cement floor4 ,this1 on cooling1 should have a few spots on the surface about the size of a threepenny-piece1 and on the under side should be bright nearly all over4 ,solder of this quality would1 if properly used1 stand any pressure without sweating4 ,if the solder on the stone or cement floor looks white on both sides1 or has a few small bright spots on the under side only1 it is too coarse and requires more tin4 ,on no account should the solder be heated to redness1 as the tin rises to the top and quickly turns to dross 7see p4 #aa74 ,if this should happen to solder that is being used for service pipes1 it should be rectified by adding more tin4 ,illustration3 ,fig4 #df ,fig4 #dg ,fig4 #df4--;,copper-bit ,joint on ,lead ,pipe ,fig4 #dg4--,wiped ,joint on ,lead ,pipe ,to purify a pot of 8poisoned0 solder 7solder that contains zinc71 melt1 stir in a handful of common sulphur or powdered brimstone until the mass is of the constituency of wet sand1 heat to the ordinary working temperature1 and carefully remove the crust that forms on the top1 and the solder will then be fit for use1 except that a little tin must be added to it4 ,the presence of zinc in solder can be detected by the difficulty of forming joints1 the metal falling apart and working very lumpy1 and the joints when finished having a dirty grey appearance4 ,when plumbers' solder is bought ready for use from the manufacturers1 it is usually in the form of casts of eight bars1 weighing about #ef lb4 to the cast4 ,the best only should be used1 as cheap solder is frequently the cause of much trouble if used on high-pressure work1 and joints made with it are never of good appearance4 ,to test manufacturers' solder1 wipe a joint with it1 and if it is of good quality it will work easily at a good heat1 and when cleaned off with tallow and a clean rag it should be well covered with bright spots4 ,brass fittings should not be tinned by dipping into the solder pot1 as brass being an alloy of zinc and copper1 the zinc may be melted into the pot with disastrous results4 ,flux4--,the flux used is tallow1 no other flux answering the purpose so well1 although mutton fat has been used as a substitute4 ,plumbers often call tallow 8touch10 and they frequently use it in the form of tallow candles1 the cotton wicks coming in handy for packing spindles of taps and slides of gas pendants4 ,an excellent plumbers' black1 soil or smudge1 can be bought in packets1 and requires only to be mixed with water before using4 ,ordinary black consists of lampblack1 glue1 and water4 ,the black should be first mixed with water1 afterwards adding the glue1 which must have been previously melted in a glue-pot4 ,simmer this for a time to remove surplus water4 ,test the black on a piece of sheet lead and dry off slowly4 ,if it chips1 add more black1 but if it rubs off add glue4 ,the black should be made in small quantities1 as it deteriorates if kept4 ,illustration3 ,fig4 #dh4--;,joints prepared for ,jointing ,illustration3 ,fig4 #di4--,marking-gauge for use on ,pipe ,ends ,another recipe is to place in the pot #a_/d lb4 of size or diluted molten glue and a little water2 gently warm until the size dissolves1 but do not boil4 ,mix #a_/b cub4 in4 of chalk ground to a fine powder with a pennyworth of lampblack1 and then with a pallet knife incorporate some of the melted size with the mixture on a flat board or stone to form a thin paste1 after which place the whole in the pot1 warm1 and stir together thoroughly4 ,test as before4 ,old and thick soil is thinned with porter or stout1 but do not add too much or the soil will become so sticky that the solder will cling to it4 ,a little brown sugar1 or a little stout1 added to the black will make it more tenacious1 and cause it to dry with a slightly glossy surface4 ,some plumbers soil their joints after they are made1 with black japan or thinned ,brunswick black4 ,but it is doubtful whether the effect is so good as when a 8dead0 black1 such as given by ordinary soil1 is used4 ,the ,cloths4--,solder cloths for underhand joints should be from #a_/b in4 to #g_/h in4 wider than the joint for which they are to be used1 and about #a_/b in4 longer than they are wide4 ,most plumbers use the same cloths for underhand and upright1 but it is preferable to use a special cloth for #d-;in4 upright joints with the length #a in4 less than the width4 ,for getting up the heat of an underhand joint on a small pipe a larger cloth may be used until the worker is sufficiently skilled in joint wiping not to burn his fingers when using the correct size4 ,for #c-;in4 joints and upwards a large cloth must be used first to get up the heat1 the wiping cloth being kept warmed and ready for use when the heat is right4 ,this large cloth1 as used by some plumbers1 is often long enough to lay on the worker's arm1 but this is clumsy to use when the joint to be wiped is in a cramped position1 and is liable to let the pipe get burnt1 as the metal it holds cannot be readily distributed round the joint2 #h in4 by #i in4 is a good size to practise with on the bench1 and as more skill is obtained it can be reduced to #g in4 by #g in4 ,a diagonal strap should be stitched to the back to take the little finger and thumb2 the position for this can be obtained by laying the cloth face downwards and placing the hand on it with the finger slightly spread2 the wrist should be over the right-hand corner1 so that when the cloth is being used the edge is readily kept parallel with the sides of the pipe4 ,branch cloths are made from #a-a_/b in4 to #b-a_/b in4 wide and about half as long again in width4 ,these cloths should be about seven thicknesses of material1 all others being nine or ten4 ,white moleskin cloth is obtained from the tailor's for making these solder cloths1 is usually #a yd4 wide1 and costs about #cs4 per square yard4 ,the usual method of making cloths is to cut a strip down the selvedge of the material and fold up the strip till the desired size is obtained2 it can then be cut off the piece1 and any odd ends left may be used for packing a larger cloth4 ,another method is to cut a square piece the required size1 and then fold it three times each way4 ,this makes a rather clumsy cloth for small sizes1 but makes a very good 8blanket40 ,horizontal or ,underhand ,joints4--,for making a successful wiped joint1 the ends to be joined must be a good fit and the temporary fixing must be sufficiently strong so that the joints will not be broken in the process of wiping4 ,these two points should be always strictly attended to4 ,service pipes should be tightly pressed home one in the other1 the cupped or female end shaved inside with a knife1 but not close in as is the case with soil or waste pipe2 this allows the solder to fill up the cavity1 which effectually prevents any tendency to sweat4 ,this principle is followed up by some plumbers with branch joints on small size service pipes1 the male end being worked in with a twisting motion1 to prevent any solder getting into the pipes4 ,all other pipe joints should be closed1 the female end being tightly worked in round the male end of pipes as an extra precaution against the solder getting inside4 ,it is a good plan to black the inside of waste and soil pipes1 so that the solder will not adhere if any should get through when making the joint4 ,fig4 #ej shows the wiping of an underhand joint4 ,beginners often spend a lot of time practising 8rolling0 underhand joints4 ,this is bad practice1 and will be of no use in wiping fixed joints4 ,little advice can be offered with regard to the actual wiping1 constant practice being the essential thing4 ,see that the solder is at the correct heat4 ,this is readily found by dropping a piece of newspaper into the pot1 and1 if it quickly browns1 the solder is ready for use4 ,if the solder is used too hot it will quickly burn holes in the pipe1 and if not hot enough a heat cannot be properly worked up1 and the cloth may get torn trying to move hard metal4 ,for underhand joints pour on steadily with a circular motion on to the sides of the joint1 and on to the soil at the ends of the joint1 until sufficient solder in a molten condition can be brought up to cover the top of the joint with the cloth1 which is held underneath it2 then pour steadily all over the solder until it runs back again4 ,repeat this continuously until the solder can be worked in a substantial body all round the joint without any hard solder being left at the underneath edges4 ,give the joint a last pour on1 and wash all the solder into the cloth4 ,bring the solder smartly on to the top1 and quickly work it all round the joint with the wiping cloth1 using two fingers of one hand for the top and back edges1 and the index fingers of both hands for the underneath part4 ,the top of the joint should be roughly shaped first and the surplus metal brought over the back to the underneath2 this should be worked into the bottom of the joint with a slight sideways motion4 ,the extra body of metal should be used to warm up any hard edges1 the surplus being brought up again to the top and quickly thrown off to the back4 ,illustration3 ,fig4 #ej4--,pipes ,supported and ,secured on ,bench for ,joint ,wiping ,illustration3 ,fig4 #ea4--;,finished ,wiped ,joint ,upright ,joints4--,these are more trying to the worker's patience but are the easier to wipe4 ,after the pipe has been fixed in position1 a lead collar should be fixed a few inches below the joint to catch the surplus metal4 ,a piece of stout string tied by a half hitch round the pipe will prevent any leakage of the solder4 ,in working up the heat of an upright joint1 care should be taken to work steadily round the joint so that the heat is the same throughout4 ,after sufficient metal has been splashed on with the splash stick and ladle1 and the metal is at a moving heat1 roughly shape up the joint with the splash stick1 keeping the metal fairly high on the joint2 then splash on a little more hot metal all round4 ,a warm cloth is now used to shape up the joint by bringing the lower metal up to the higher part1 after which start to wipe first with the hand as far round the back of the joint as possible and bring the surplus metal to the front1 the cloth being held by the thumb and the index and little fingers2 then change the cloth to the left hand and repeat the operation4 ,the joint should be finished off at the back1 although if quickly done the finish off should not be apparent4 ,the collar must now be taken off and the solder it contains melted with a plumber's iron4 ,a plumber's iron can be used to good purpose on these joints1 especially if they are out of doors and the weather is rough4 ,the iron must be heated to redness and well filed up4 ,illustration3 ,fig #eb4--,making ,upright ,wiped ,joint ,illustration3 ,fig4 #ec4--,wooden ,collar or ,platform to ,catch ,waste ,solder ,illustration3 ,fig4 #ed4--,lead ,collar to ,catch ,waste ,solder ,illustration3 ,fig4 #ee4--,pipes fully prepared for ,jointing ,where possible1 all joints to be wiped in their permanent position are sprung away from the wall and temporarily fixed with steel points made from #a_/b-;in4 hexagon steel about #i in4 long and drawn out to a point at one end4 ,in some cases1 more particularly soil-pipe work1 the pipes cannot be fixed away from the wall2 a hole must then be cut into the wall about #d in4 back and about #ab in4 square to allow the joint to be properly made at the back4 ,wiped ,joint between ,lead and ,cast-iron ,pipes4--,in wiping a lead pipe to a cast-iron pipe perhaps the best practice is to file clean the end of the cast-iron pipe first and then coat with pure tin1 sal-ammoniac being used as a flux4 ,the pipe then is washed to remove the sal-ammoniac1 and afterwards 8retinned10 using resin and grease as a flux4 ,a plumber's joint then is wiped in the usual way4 ,it is necessary to take great pains to make a good sound strong joint between the two metals1 but even then in the course of time 7it may be only a few years7 the iron will come out of the solder4 ,the first sign of decay will be a red ring of iron rust showing at the end of the joint4 ,this rust will swell a little and cause the end of the soldering to slightly curl outwards4 ,eventually the rust will creep between the solder and the iron and destroy the adhesion of the one to the other4 ,the joint would eventually become a loose ring on the iron pipe1 but not on the lead pipe1 as the expansion of lead and solder do not differ to any great extent4 ,only those metals that alloy together can be satisfactorily joined by soft soldering1 and the solder should contain as great a proportion as possible of the metals to be united4 ,the illustrations to this chapter 7,figs4 #df to #ee7 are self-explanatory4 ,,chapter ,,viii ,hard-soldering with ,silver ,solder ,hard-soldering is chiefly of two kinds1 brazing and silver-soldering1 the former being employed for iron and steel1 the solder used being known as 8spelter10 a brass alloy which can be obtained in various degrees of fineness4 ,for copper1 brass1 and nickel silver1 alloys containing silver are the best solders4 ,in both forms of hard-soldering1 the flux is borax4 ,the methods of silver-soldering vary with the size of the work4 ,a jeweller may hold the work in his hand1 on the end of a piece of binding wire or on a square of charcoal1 the heat being applied by a mouth blowlamp from a horizontal gas jet1 as already described4 ,larger work demands a flame of greater intensity1 and sufficient air can be supplied only by a footblower or similar device1 or1 as an alternative1 from the flame of a suitable blowlamp4 ,silver ,solder4--,this can be purchased at prices up to #cs4 #f;d4 or so per ounce in sheet form1 about #a_/cb in4 thick4 ,where the solder is melted down by the amateur1 a good way to obtain the sheet form is to turn the globule of molten metal on to the bench and to place a flat iron on it2 but the result will not be equal to a rolled ingot4 ,an old shop method of making silver-solder is to melt up old silver 7using current silver coinage is an expensive method of obtaining the silver1 and is said to be illegal7 with some brass pins1 not the iron ones so common now4 ,according to ,w4 ,h4 ,jubb1 two solders compulsory for silver articles that have to be sent to assay for hallmarking are3 7#a7 #ab parts standard silver and #a part brass2 7#b7 #f parts standard silver and #a part brass4 ,no4 #a has a low melting point1 and is termed 8quick10 and ,no4 #b1 which requires a higher temperature1 is called 8stark0 7in some parts of the country1 8fine071 but the use of this term here is misleading4 ,no4 #b should be used at the first heating and ,no4 #a at the second4 ,these should make ideal solders for beginner's use1 as the chances of burning the work1 even thin brass1 are almost nil4 7#c7 #b parts brass1 #a part standard silver2 7#d7 #e parts brass1 #b parts standard silver4 ,whereas ,nos4 #a and #b are 8silver solders10 ,nos4 #c and #d are termed 8,german silver solders10 as they are not so white and are used on ,german or nickel silver 7an alloy of copper and nickel74 ,both ,nos4 #c and #d are good1 have a comparatively low melting point1 are much less expensive than ,nos4 #a and #b1 and1 if plenty of wet borax is used1 will 8strike up0 well4 ,no4 #c is recommended4 8,standard silver0 is about #ie per cent4 pure silver4 ,old 8sterling silver0 is #ibe per cent4 pure silver4 ,in making any of the above solders the brass and silver should be melted together1 and care should be taken to see that the metal is clean beforehand4 ,where large quantities of solder are made1 the metals are scoured with emery cloth before they are put into the crucible4 ,requisites for ,silver-soldering4--,for light jobs in silver-soldering the special tools and materials required are as follow3 ,suitable gas jet or other flame1 mouth blowpipe1 scraper1 jar containing a sulphuric acid 8pickle10 piece of slate1 camel-hair brush1 pieces of lump borax1 two grades of silver solder1 charcoal block1 iron binding wire4 ,the pickle is made by pouring #a part of common sulphuric acid into #bj parts of water1 and its function is to remove all dirt and borax from the metal4 ,silver-soldered articles should not be thrown into the pickle until they are nearly cold1 as otherwise the joints may crack1 but in the preparatory annealing 7that is1 softening7 of plain metal1 wire1 rod or tubing1 the article may be put into the pickle when hot--but take care of the splashes6 ,plunging hot copper or brass into cold water does not have the effect of hardening it4 ,before placing a job in the pickle1 remove any iron binding1 as this is immediately attacked by the acid4 ,often it is advisable to heat the metal and put it 8through the pickle0 before working on it1 especially in the case of tubing that has been lying by for some time and has become dirty4 ,for heavier work1 a foot-bellows and gas blowpipe1 or else a blowlamp1 are essential4 ,an 8tna0 paraffin blowlamp with horizontal burner will be found quite satisfactory1 although1 of course1 if a gas supply is available in the workshop the user will find that a foot-bellows and blowpipe are more convenient4 ,a blowlamp or blowpipe requires a suitable tray or 8forge0 of sheet-iron in which coke and odd pieces of brick or tile may be laid and used to pack round the object whilst the flame is being played on the part to be soldered4 ,illustration3 ,figs4 #ef and #eg4--;,clip for ,holding and ,applying ,silver ,solder ,illustration3 ,fig4 #eh4--,pricker and ,spatula for ,consolidating ,joints and ,applying ,solder ,among the smaller additional tools that will be required will be a clip to hold the solder 7,figs4 #ef and #eg7 and a brass pricker 7,fig4 #eh74 ,preparing the ,borax ,flux4--,make up the flux on the slate by rubbing on it a piece of the lump borax moistened with water4 ,this paste may be applied with the camel-hair brush to the parts to be jointed4 ,the flux prevents the oxidisation of the surfaces1 which would resist the amalgamation of the metals and the solder4 ,the ,method of ,silver-soldering4--,in hard-soldering with silver solder1 first file or scrape the parts bright1 and cover them and the solder with the borax paste4 ,heat gently at first so as to harden the borax2 then continue to heat by blowpipe until a red heat is reached1 at which the solder will run4 ,the secret is to blow continuously until the solder runs1 and not to stop half-way4 ,for soldering a silver watch case1 an ordinary easy-running silver solder1 which melts at a lower heat than silver1 will do4 ,but to make sure1 shred the solder into very thin strips1 and apply plenty of borax to them as well as to the joint to be united4 ,use the blowpipe gently at first so as to bake the borax1 then heat the case all over almost to the melting point of the solder1 and direct the flame to the part to be soldered until the solder runs and glistens4 ,cease blowing instantly1 and plunge the case into a solution of sulphuric acid #a part and water #aj parts1 to whiten it2 then wash in hot water and dry in sawdust4 ,be careful to remove all steel springs before soldering the case4 ,soldering ,small ,work with ,paillons4--,these are small squares1 say1 #a_/h in41 of sheet silver solder1 made by using the snips as in ,fig4 #fa1 and prepared by well covering with the borax paste4 ,each paillon is placed in position with the tip of the brush1 this job requiring a little practice4 ,the solder should be clean1 and if not1 should be made so by passing through the fire and pickling4 ,the work with the paillons in position should be slowly heated by blowing the gas jet on a part of the job farthest away from the solder2 the borax will dry1 and should the solder have moved1 replace it with a suitable tool or the point of the wet camel-hair brush4 ,the heat must not be applied too suddenly at first1 otherwise the borax will boil up and push off the pieces of solder4 ,the heat may be increased when the bubbling has ceased4 ,do not hold the work too far away1 or it will get dirty in the smoke of the flame1 or yet too near1 else the gas will not be used to advantage4 ,as the work begins to get hot1 slowly work the flame towards the joint until the solder melts and runs into the joint4 ,give it now a little extra heat to get the solder thoroughly down into the crevices1 and then let the work cool down4 ,when nearly cold twist off the iron binding wire and put the job into the pickle4 ,leave the work in the pickle about ten minutes1 when all the borax will be dissolved4 ,illustration3 ,fig4 #ei4--,section through ,pipes prepared for ,silver-soldering ,illustration3 ,fig4 #fj4--,pipes prepared for ,silver-soldering ,illustration3 ,fig4 #fa4--;,cutting ,up ,silver ,solder into ,paillons ,larger ,work4--,an example of silver-soldering larger work is the joining together of two pipes1 one smaller than the other4 ,the best course to adopt is to file or scrape the end of the smaller and the inside of the larger 7reaming and filing them if necessary7 until a good fitting joint is obtained1 as in ,figs4 #ei and #fj4 ,a strip of solder is then cut off1 and1 after the joint is well coated with borax paste1 this solder may be wound round the smaller pipe4 ,if the joint is soldered in a vertical position1 the larger pipe should be the lower4 ,the heat should be conserved by laying the work in the coke and building the same round1 or1 if the work is too large or the joint in an awkward part of the pipe1 a shield of tin plate or iron should be placed behind the joint so that the flame is thrown back on to the work4 ,should the pipe be attached in close proximity to the joint to a heavy piece of metal1 then warm this metal up first1 otherwise all the heat will travel to this part1 and the work will take much longer to get to the proper temperature4 ,in all cases where one part of the joint is of heavier substance than the other1 that part should receive the greater amount of attention from the flame4 ,quenching ,silver-soldered ,work4--,many craftsmen object to the cooling of the work by plunging it into water or pickle whilst it is hot2 but no damage or cracking of the joint occurs1 it is thought1 if the work is not plunged when it is red hot or anywhere near red hot4 ,plunging into a pickle certainly cracks the burnt-in borax1 which can be readily removed and the joint examined to better advantage4 ,many a silver-soldered joint has been passed as quite sound when it has only been the borax that has been stopping the interstices1 and only after it has been placed under service for some time does the faulty joint make itself apparent4 ,silver-soldering cannot be done on work that has been previously soft-soldered unless the soft-soldered part is first cut away2 but1 of course1 soft-soldering can be readily accomplished after silver-soldering or brazing so long as the work is clean and all burnt borax is first removed4 ,removing ,soldering ,marks4--,solder will run away from a part of a joint instead of running into it when the edges of the joint have been imperfectly cleaned preparatory to the application of flux and solder2 also1 if some dirt has got into the flux1 or on the paillons of solder employed4 ,another cause is unequal heating of the joint1 or allowing it to expand too much whilst being heated4 ,the resulting fire marks may be removed by warming the articles on a pan over gas1 and plunging them whilst warm into the sulphuric acid pickle4 ,or the marks may be removed in a hot and strong solution of potassium cyanide1 and the polish renewed by a light polishing with a revolving swansdown mop and rouge composition4 ,,chapter ,,ix ,soldering ,gold and ,silver ,jewellery ,two methods of soldering are in common use among jewellers and silversmiths4 ,soft-soldering is done with fine solder 7#a of lead and #b of tin71 and is used for articles that will not bear much heating4 ,the metal is filed or scraped clean and bright where the solder is wanted to run1 killed spirit is applied1 and a little solder is run on the surfaces by applying gentle heat4 ,having thus been 8tinned10 the parts are placed together and heat applied until they unite1 a spirit lamp or a blowpipe being used4 ,this is the sweating process1 already referred to a number of times4 ,for soldering catches and joints to cheap metal brooches that have been silver-plated or gilt1 the same solder is used as in the above4 ,both catches and joints can be cheaply purchased1 hard-soldered on to small plates1 square1 oval1 or crescent shaped1 to suit all kinds of brooches4 ,take one of these and hold it with an old pair of soldering tweezers in the flame of a spirit lamp1 and give it a coating of solder on its under side4 ,first wet it with the killed spirit1 and then place a small portion of solder on it1 and hold it in the flame until it flows all over the plate4 ,it can be assisted to flow evenly by a copper wire1 which is also useful to apply the acid flux4 ,having 8tinned0 the catch1 clean 7by scraping bright7 the brooch1 and place the catch in position4 ,direct a gentle blowpipe flame to it until it is seen to settle down and the solder flows4 ,then wash it immediately in warm water to remove the acid and dry in sawdust1 kept in a warm place4 ,use as little solder as possible1 and only clean the brooch where the solder is required to run4 ,attention to these points will ensure a neat job4 ,hard-soldering on jewellery1 etc41 is done with silver or gold solder1 and requires the articles to be heated to a bright red4 ,the parts are cleaned1 and a paste of borax and water is applied as a flux4 ,a small piece of the solder is also dipped in the borax paste and laid over the join4 ,gentle heat is first applied to bake the borax hard1 then by the use of a blowpipe the parts are raised to a red heat until the solder runs4 ,the instructions given in the preceding chapter apply generally4 ,with regard to gold-cased jewellery1 it is useless to attempt to hard-solder gold that has the least trace of soft solder or lead on it2 the heat causes the lead to heat into and rot the gold1 and the articles will tumble to pieces4 ,the only way to mend1 say1 a gold-cased lead ring is by soft-soldering a tin band or plate over it1 applying the heat very gently to avoid melting the lead inside4 ,for hard-soldering a gold ring without discolouring it1 use solders containing gold1 the precious metal in the solder being afterwards laid bare by a process of annealing and pickling4 ,the solders are prepared to suit the quality of the gold to be soldered1 so that they may 8colour0 well and thus hide the joint4 ,the following is a list of coloured solders3 ,best solder3 ,fine gold1 #ab-a_/b parts2 fine silver1 #d-a_/b parts2 copper1 #c parts4 ,medium3 ,fine gold1 #aj parts2 fine silver1 #f parts2 copper1 #d parts4 ,common3 ,fine gold1 #h-a_/b parts2 fine silver1 #f-a_/b parts2 copper1 #e parts4 ,the gold solder is cast in long ingots1 rolled thin and flat1 and cut up or filed into dust1 and thus applied to the cleaned joints1 using borax as a flux4 ,after the joint has been closed under a blowpipe flame1 the whole ring is annealed on an annealing plate to a dull red heat1 then cooled1 pickled in acid1 and polished4 ,the film of grease left by the polishing process is washed off in hot soda water1 and the ring dried in hot sawdust4 ,hard-soldered rings may be coloured with a film of electro-deposited gold4 ,if the gold is of common quality1 under #ab-;carat1 to remove any excess solder make a mixture by reducing to powder #a oz4 of green copperas and #a_/b oz4 of saltpetre and boiling in #e oz4 of water4 ,this will crystallise when cool4 ,redissolve the crystals in eight times their bulk of muriatic acid4 ,for use1 add boiling water1 and place the gold in the hot mixture4 ,for gold of #ab-;carat or over1 nitric acid and water 7#a part of acid to #b of water7 will dissolve the solder without injuring the gold4 ,gold solders used on gold articles are made from gold of the quality of the article--say1 #ah- or #ae-;carats--to which is added #a_/abth or more of silver and #a_/bdth or more of copper4 ,the quality of the solder is always a trifle inferior to the metal on which it is used1 so that the solder may melt at a lower heat than the article4 ,the melting point of #ah-;carat gold is #aiie ,f41 of #ae-;carat #aiib1 and #i-;carat #aigi1 while easy silver solder melts at about #ahjb ,f4 ,this shows that although #i- or #ae-;carat gold could be used to solder #ah-;carat1 it is not possible to use #ah-;carat to solder #ae-;carat4 ,the same principle applies to silver and brass2 and the quality of the solder has to be known before any attempt should be made to carry out the actual soldering of an article4 ,another important point is that thin gold articles1 like brooches1 will not bear so hard a solder as the same quality of gold will do when made up solid1 as in the case of a bangle ring4 ,solder for #ah-;carat and #ae-;carat is made thus3 ,take #a dwt4 of the gold1 and add #b gr4 fine silver and #a gr4 fine copper2 melt well together1 and roll out thin4 ,for #ab-;carat1 the addition of #c gr4 fine silver and #a of fine copper to the dwt4 is advisable2 while for #i-;carat the most useful solder is made from #a part fine gold1 #a part fine copper1 and #b parts fine silver4 ,great care must be exercised in hard-soldering gem jewellery1 as the stones are likely to be injured4 ,diamonds are the only stones that it is safe to heat to redness in soldering4 ,fancy coloured stones1 such as rubies1 emeralds1 sapphires1 topazes1 amethysts1 garnets aquamarines1 or pastes must not be made hot4 ,a ring with any of these stones may be hard-soldered at the back if the stones are covered up with a pad of wet tissue paper to keep them cool2 but if the soldering has to be done anywhere near the stones1 they must all be taken out by un-setting4 ,articles set with pearls1 turquoises1 opals1 or cat's-eyes 7these things are not really 8stones07 will bear no heat whatever1 and must all be taken out before soldering4 ,in cases where it is very desirable to leave the stones in place1 in order to prevent their bursting when heat is applied to the jewellery1 cut a juicy potato into halves and make a hollow in both portions1 in which the part of the ring having jewels may fit exactly4 ,wrap the jewelled portion in soft paper1 place it in the hollow1 and bind up the closed potato with binding wire4 ,now solder with easy-flowing gold solder1 the potato being held in the hand4 ,another method is to fill a small crucible with wet sand1 bury the jewelled portion in the sand1 and solder in the usual way4 ,to restore the colour of gold or silver after soldering1 dip the articles while hot into pickling acid 7#a part of sulphuric acid to #aj parts of water72 or put them in a little acid in a pan and boil them in it4 ,here1 again1 diamonds are the only stones that may be dipped hot1 and there is a slight risk even with them4 ,pearls1 etc41 must not touch the acid1 either hot or cold4 ,after heating and pickling1 all gold is of a pale colour1 and the commoner the gold the paler4 ,however1 #ah-;carat gold may be restored to its original colour in a few moments by buffing with rottenstone and oil on a leather buff or on a brush1 and following with rouge in the same way2 or it may be burnished if the nature of the article permits this4 ,poorer qualities of gold may be restored to their bright colour by the same means1 but this takes longer4 ,most #i-;carat articles are gilt to improve their colour1 and after soldering must be re-gilt to restore their original appearance4 ,,chapter ,x ,brazing ,hard-soldering by brazing with spelter is used to a very great extent in the metal industries1 especially in the manufacture of cycles and motor-cars4 ,although several mechanical joints have been tried in cycle manufacture1 the greatest number of joints are made by means of brazing solder4 ,a joint made in this manner is almost as strong as a weld1 and the steel tube itself will often break under a strain and the brazed joint remain intact4 ,copper and brass tubes1 when well brazed1 will stand a pressure of #dj lb4 or more per square inch4 ,spelter4--,hard brazing solder 7spelter7 is somewhat difficult to make4 ,the metals have to be melted in a crucible and cast at a proper heat1 and while in a certain condition have to be pounded or punned in a mortar4 ,this disintegrates the materials and forms crystals of various sizes1 some being as coarse as wheat grains1 varying in fineness down to that known as #j #j1 which is very fine dust indeed1 and used only on very particular work1 such as tubing #a_/h in4 or #c_/af in4 in diameter4 ,the quantity of #j #j from #a cwt4 of solder is very small1 the corresponding quantity of coarse grains being much larger2 so that unless a quantity is required1 it is cheaper to buy than to make4 ,it is necessary to employ the purest materials1 and in purchasing hard solder it is advisable to state the purposes for which it is to be used4 ,as a general rule1 a solder should melt at a heat just under the melting point of the metals to be united4 ,now1 in ironwork1 or with the steel used in cycle work1 this is impossible1 for the melting points of these two metals are too high to be effected by the bunsen blowpipe or brazing hearth2 but to join two metals in which the melting point approximates very closely to that of the solder requires great care in order that the metals may not be fused and the join spoiled4 ,the reason why the melting point of solder should be about the same as that of the metals being joined is apparent when it is remembered that heat and cold1 vibration and concussion1 tension and compression1 have very considerable effect on metals1 and that if the expansion and contraction of these under working conditions is not nearly alike1 disruption or opening of the joint will follow4 ,hard solders or spelters are mainly composed of copper and zinc--that is1 they are brass alloy--the quality most extensively used consisting of equal parts of copper and zinc4 ,as the quantity of copper in the solder is increased1 so the fusing or melting point is raised4 ,ordinary copper melts at about #b1jjj ,f4 and zinc at about #hdj ,f41 and a solder composed of equal parts of each metal has therefore a high melting-point4 ,a very hard solder consists of equal parts of silver and copper4 ,generally1 a spelter of different composition is required for iron1 copper1 and brass work1 that for the latter being required more readily fusible than that for the former4 ,a suitable spelter for ironwork is one composed of #b parts copper and #a part zinc2 a spelter for copper consists of #c parts copper and #b parts zinc2 while equal parts of copper and zinc make a suitable spelter for ordinary brass work4 ,if a very low melting point be required1 a little silver should be added to the last-given spelter4 ,the ,flux4--,borax is the best-known flux for brazing4 ,it is beneficial1 however1 to have the borax calcined 7fused71 as it settles down to its work immediately when applied to the hot metal1 whereas uncalcined borax has a tendency to swell and fall off the work4 ,spelter is in the form of filings1 a thin stick1 or wire4 ,filings are apt to be blown from the work4 ,brazing is a very useful1 and1 if properly done1 reliable1 method of joining two pieces of iron4 ,a brazed joint is considerably stronger than a soft-soldered one1 and easily resists temperatures that would cause ordinary solder to run4 ,the process is not at all difficult if there is sufficient heat1 and1 for those who have no gas laid on1 the purchase of a paraffin tna brazing lamp can be recommended4 ,with this lamp1 of course1 the bellows is not used1 and only an iron hearth with asbestos cubes is wanted2 but gas should be used if available4 ,the ,method4--,for satisfactory brazing1 thoroughly clean the surfaces to be joined1 first with a file and then with emery-cloth1 and1 if necessary1 bind them together with thin iron wire4 ,a flux of borax and water mixed up into a thick paste is smeared round the joint1 which should then be warmed to get rid of the moisture4 ,heat the metal to a white heat1 dip the spelter into the borax paste1 and apply to the part to be joined1 rubbing round the joint until the brass is seen to run1 when the heat can be cut off4 ,the work should be almost covered in the asbestos cubes1 and the spelter applied all round and not only in one place2 failures to unite the parts mostly result from insufficient heat or cleaning of the parts4 ,brazing-lamps4--,these lamps are constructed to burn benzoline or paraffin1 and the more powerful types are fitted with pumps so that air pressure may be exerted on the oil4 ,the paraffin or benzoline is thus forced into the burner1 and by passing through the previously heated tubular coil is converted into gas1 which issues forth out of the gas nipple1 mixes with air1 and then burns with a blue atmospheric flame of high temperature4 ,after filling the lamp1 a torch should be held under the burner to vaporise the oil1 and thus ignite the lamp1 after which pressure is applied by means of the pump4 ,do not start pumping too soon--that is1 before the burner is sufficiently hot to vaporise the oil--or the oil itself will be forced through the gas nipple4 ,the flame may be regulated at will1 to suit the work in hand1 after the burner has become thoroughly hot to set the lamp fairly going4 ,when brazing1 lay the article to be brazed on some broken coke1 charcoal1 or firebrick1 and if the article is comparatively heavy1 cover it over with some small pieces 7to conserve the heat7 except where the brazing is required4 ,after applying flux and spelter to the previously cleaned metal1 direct the flame of the lamp on it1 gently at first1 until the spelter fuses and makes the joint4 ,gas ,blowpipe for ,brazing4--,brazing blowpipes should be fitted with a combination air and gas regulator1 by means of which both the size and nature of the flame can be adjusted to suit the work in hand4 ,when choosing a blowpipe it is always better to make one rather larger than the work in hand necessitates--the flame can be reduced when required2 by this means a margin of reserve is provided which is useful in emergencies4 ,a blowpipe whose dimensions are #aj in4 long1 having a #e_/h-;in4 gas supply reduced to #g_/af in4 at the nozzle1 and a #c_/h-;in4 air supply reduced to #c_/af in4 at the nozzle1 will braze ordinary latch keys and other similar work if used with a ,no4 #c size blower4 ,as already stated1 a paraffin1 petrol or benzoline blowlamp is a cheap and effective apparatus1 especially where the quantity of work to be done does not warrant the outlay of a foot blower1 gas blowpipe1 etc41 but gas has advantages over the liquid fuel1 inasmuch as the blowpipe is more under control4 ,the quantities of gas and air can be readily and more delicately adjusted during the actual brazing process1 then as soon as the spelter fuses and the gas is turned off1 the stream of cold air soon counteracts any excessive heat4 ,making a ,gas ,brazing ,hearth4--,the brazing hearth can be bought ready-made1 or can be cheaply put together by the worker himself1 the necessary materials consisting of two bellows1 some lead piping1 and an old packing case to support a large size frying-pan--about #a ft4 #d in4 by #a ft4 ,the bellows are fixed one above the other1 interconnected by a fixed lead pipe1 one pair of bellows worked by the foot pumping air into the pair above it1 from which the air is taken to a bunsen blast burner by flexible tube4 ,this bunsen burner can also be easily and cheaply made1 and as this works very well and will be found useful for both soldering and brazing1 the following hints on making it are given4 ,first1 get two ordinary large house bellows about #a ft4 square1 or larger if possible2 the larger the better4 ,next a good strong packing case about #b ft4 long by #a ft4 #c in4 high and #aj in4 wide is required4 ,one end of the box will form the base1 and to make it steadier two #a-;in4 boards should be screwed across to protrude about #f in4 on each side1 the front one being considerably wider1 as can be seen at ,t 7,fig4 #fb71 which shows the apparatus with one of the case sides removed4 ,the packing case proper is denoted by the letter ,a2 the part ,a ,s ,a was formerly the bottom of the case1 but is now the back2 and the top ,a ,v ,a was the end of the packing case4 ,half-way between the top and bottom a shelf ,b should be fixed1 having a large hole cut out of the middle at ,g to accommodate the union piece 7seen in section71 which holds the lead air-pipe communicating from the lower bellows to the upper4 ,illustration3 ,fig4 #fb4--;,home-made ,brazing ,hearth ,in the back1 near the bottom1 at ,s1 cut a hole for the nozzle of one of the bellows1 and above the shelf cut another hole at ,s#a to take the nozzle of the other bellows4 ,the bottom bellows ,c should have the top handle extended by a piece of stout bent iron ,n to act as a pedal1 and should be screwed to the base4 ,a central hole about #c in4 in diameter should be cut at ,p to allow the air to reach the valve4 ,now get a piece of lead pipe #a_/b in4 inside diameter1 and1 having cut down the nozzle to just under that diameter1 force the mouth of the pipe over it as at ,s1 and bend the pipe ,f as shown1 to reach the centre of the shelf ,b and enter the hole ,g until flush with the top4 ,remove the lead pipe and get a block of wood about #c in4 square4 ,cut off the corners and bore a hole in the middle1 so that the lead pipe will just pass through it1 and countersink the hole4 ,broach out the mouth of the lead pipe until it becomes bell-shaped and fits the block of wood1 so that its edge is flush with the wood when pressed hard against it4 ,this is clearly shown at ,g1 where the dark shading represents the wood block4 ,cut a leather washer the size of the block1 with a #a_/b-;in4 central hole1 and lay this over the hole in the bottom of the top bellows where the leather flap valve is4 ,bore two holes in the wood block1 and screw this down tightly to the bottom of the bellows1 so that the bell-mouth of the lead pipe faces the hole and has the leather between it and the block4 ,this should make an air-tight joint for the fixing of the pipe to the bellows4 ,next1 push the nozzle of the bellows through the hole ,s#a1 and screw the bellows down tightly to the shelf ,b4 ,join the lead pipe to the nozzle of the bottom bellows1 and make an air-tight joint with glue and tape bound round4 ,between the top of the upper bellows ,d and the top of the packing case at ,v1 a stout sofa spring ,e is fixed to keep the top bellows shut down tight till air is pumped in from the bellows below4 ,from a screw near the top of the case stretch a house-bell coil spring ,m1 and attach its lower end to the foot-plate or pedal ,n4 ,this spring tends to keep the lower bellows open4 ,when pressure is put on the foot-plate ,n1 air is pumped from the lower to the upper bellows1 and thence along the flexible pipe ,r to the bunsen blast nozzle described in detail later4 ,if it were not for the upper bellows1 the air would come to the nozzle in puffs1 but the spring ,e keeps the pressure constant1 and a steady blast is secured4 ,the rubber pipe ,r should be of sufficient length to reach the hand conveniently1 and allow room for movement4 ,the hearth ,k can be made from sheet-metal1 with the edges bent upwards to form a tray2 or an old frying-pan will answer very well4 ,whichever is employed1 four iron stays or legs ,h must be used to raise it above the top of the packing case as shown4 ,these legs should be screwed at one end to the sides of the case1 and at the other to the pan1 and if a frying-pan is used1 the handle may be cut and bent to form a hook as at ,l2 it then acts as a support for the blast nozzle4 ,illustration3 ,fig4 #fc4--;,blowpipe or ,blast ,gas ,nozzle for ,brazing ,hearth ,for use with the brazing hearth1 a blast gas nozzle on the bunsen principle is required1 and this is easily made from two pieces of gas-piping1 a right-angle joint1 and two mouthpieces to take flexible pipes4 ,first1 get #a ft4 of #c_/d-;in4 brass 7or iron7 pipe and an elbow1 internally threaded at both ends4 ,cut #b in4 off the brass pipe1 and cut a thread at one end of the short piece and one end of the long piece1 to screw into the elbow as shown in ,fig4 #fc4 ,at the other end of the long tube solder in a cock or mouthpiece to take a large diameter flexible pipe from the gas bracket4 ,next get #a ft4 of #a_/d-;in4 brass pipe1 and bend it to the shape shown at ,b1 soldering a mouthpiece at ,f to take the smaller diameter air-pipe ,r 7,fig4 #fb7 from the bellows4 ,bore a hole through the elbow ,c1 and push the pipe in1 making a tight fit1 and so that it passes centrally through the larger brass tube until it nearly reaches the end as shown at ,d4 ,run a shoulder of solder to hold the small tube firmly in the larger one as at ,e1 and unite with a drop of solder the large tube ,a and the small tube ,b where they cross at ,g4 ,the gas passes up the large pipe1 and out at ,d1 and a blast of air is forced through the centre of the flame through the small pipe ,b4 ,the shape of the small pipe allows of it being readily hung up on the hook ,l 7,fig4 #fb7 when not in use4 ,instead of the mouthpiece shown at ,h 7,fig4 #fc71 a cock will be found more convenient2 but it should not be too small1 or it will restrict the flow of gas1 which should be as great as possible4 ,no gas-cock should have less than #a_/d-;in hole4 ,the 8fuel0 7heat conservers7 consists of chunks or cubes of asbestos1 and when these are blown upon with the gas flame1 the heat is quite sufficient for moderately heavy brazing4 ,be careful not to get any kinks in the flexible tubes1 or the air and gas will be reduced in quantity1 if not stopped altogether4 ,a square of thick asbestos 7sheet7 is useful for laying on small articles whilst brazing1 and a piece or two of charcoal will be handy for silver-soldering4 ,brazing ,iron and ,steel4--,before attempting to braze either iron or steel the surfaces should be thoroughly cleaned by filing or grinding1 etc4 ,brass or copper may be cleaned by dipping in a solution of #a part nitric acid and #b parts of sulphuric acid4 ,this same solution can be used to remove the scale after brazing4 ,the parts should be fastened together in the position they are to occupy when joined4 ,the fastening may be effected by the use of wires1 screws1 bolts1 clamps1 etc4 ,if practicable1 the parts should be held in such a way that they can be turned over during the brazing process without disturbing the relation of the parts1 thus affording a better chance to apply the flux and brazing material4 ,in brazing sheet metal1 if the seams are not required to stand much working after soldering1 they may be joined edge to edge4 ,when seams are formed in this way1 little nicks1 about #a_/b in4 apart1 should be filed out along the edges1 so that the solder flowing through the nicks will render the joint sound4 ,if the seam is to be worked after soldering1 a small lap is necessary to ensure adequate strength4 ,to form seams of this type1 first thin the edge of the metal along the ends that are to form the seams1 about #a_/h in4 in from the edge1 so that when the two edges are lapped over each other the combined thickness at the seams will be the same as the single thickness of the metal at other parts4 ,cut a small cramp at the top and bottom of the seam1 and fit the opposite edge in these cramps4 ,after preparing the seams by either of the above methods1 fasten binding wire round the articles so as to hold the seams securely in position4 ,now powder some borax flux1 mix equal parts of the borax paste and grains of spelter1 and along the seams place sufficient of the mixture to solder them when melted4 ,some dry borax should also be kept ready at hand1 so that a little may be taken and thrown on the solder at any point where the material does not appear to be flowing freely4 ,gently heat the article by some suitable means1 such as foot bellows and blowpipe1 so that it will expand equally1 and not disarrange the seam2 increase the temperature until the metal is a dull red1 and the spelter runs4 ,if necessary1 with a piece of wire flattened at one end gently rub the solder along the seam until every part is joined4 ,brazing ,copper ,rod4--,for uniting two pieces of copper rod1 #a_/d in4 or #c_/h in4 in diameter1 first prepare the joint as at ,a in ,fig4 #fd1 and file the surface of the copper clean in the immediate vicinity of the joint4 ,a mixture of borax and water and spelter should now be applied to the joint1 which should rest on a small heap of broken coke1 the coke being also built round it4 ,the flame of the blow-lamp should be directed at first on the coke surrounding the joint1 and then gradually brought to bear on the joint itself4 ,if necessary1 add a little more spelter before any of it fuses1 and when the copper begins to get red hot1 throw just a pinch of dry borax on the joint to facilitate matters4 ,illustration3 ,fig4 #fd4--;,dovetailed ,joint in ,copper ,rod ,illustration3 ,fig4 #fe4--;,dovetailed ,joint in ,key ,stem ,brazing ,key ,stems4--,in brazing together the broken parts of a key stem1 first it is necessary to file the fractured ends quite true2 this may entail the shortening of the key by #a_/d in4 or #a_/b in41 and as another #a_/d in4 will be lost in making the joint1 it may be advisable to use another key bow having a longer piece of stem than the one that was broken off4 ,with a warding file cut a dovetail on each of the ends to be joined1 as shown by ,fig4 #fe4 ,a small1 half-round file will assist in making the edges true and square4 ,the pieces must interlock perfectly1 and when this is the case1 very lightly hammer the joint1 round which then bind seven or eight turns of brass wire to act as spelter4 ,wet the joint1 sprinkle powdered borax on it 7this is to serve as the flux71 and1 holding the key in a pair of tongs1 place it in a clear part of a forge fire made with charcoal1 small coke1 or coal cinders1 and commence to blow steadily the forge bellows or blower4 ,failing a forge fire1 use a blowpipe1 the key being placed on a piece of charcoal or pumice-stone whilst the heat is being applied4 ,if the forge fire is used it is as well to support the key on a guard of thick iron plate having a hole in its centre over which is the joint to be brazed4 ,by this means the necessary local heating is obtained1 and much labour in cleaning the key afterwards is avoided4 ,on being heated1 the borax swells and boils up1 and should be pressed down with a spatula1 previously dipped in cold water to prevent the hot borax adhering to it2 a suitable spatula is made by flattening one end of a #a-;ft4 length of a #a_/d-;in4 round rod1 having at its other end an eye by which it may be hung when not in use4 ,with this spatula1 also1 powdered spelter may be added to the joint if required4 ,when the brass wire begins to run1 assist the flow by adding powdered borax1 and when all the brass has run into the joint1 rub off superfluous molten metal from underneath and allow the joint to cool gradually4 ,when cold1 file up and clean the stem of the key until only a thin bright line of brass can be seen4 ,cycle ,brazing4--,in cycle brazing1 the first consideration is the means of heating the heaviest joint to a brazing heat4 ,this may be done in several ways1 by a paraffin blow-lamp costing at least #ces4 to #djs41 or1 what is better1 a gas blowpipe #g_/h in4 or #a in4 in diameter1 with at least #a_/b in4 gas supply pipe and a fan or bellows to supply the necessary air pressure4 ,a small fan is far preferable to a bellows of any description1 the flame being steady and constant1 and the operator being able to devote his entire attention to the job4 ,in the absence of power1 obtain a small circular double-blast bellows and hearth1 costing with blowpipe about #e4 ,the brazing materials are brass spelter4 ,no4 #c size1 or brass brazing wire and powdered borax2 a tin to hold the mixture of spelter and borax1 and one for the plain borax2 a piece of iron wire about #a_/d in4 by #ah in41 flattened at one end to feed the spelter and borax to the joints2 and a brazier's brush1 which is desirable1 but not absolutely necessary1 to brush the superfluous borax and brass from the outside of the joint as soon as it is removed from the hearth2 this saves much work in filing up1 and saves the files immensely4 ,do not purchase the borax ready powdered1 but buy lump borax1 as that purchased ready powdered is likely to be adulterated4 ,in making the brazing mixture1 use about equal parts1 in bulk1 of ,no4 #c spelter and borax4 ,in preparing the work for brazing1 see that the surfaces are bright1 clean1 and free from scale4 ,the joints should be a good tight fit1 free from shake1 and where a joint such as the back forks to the bridge lugs is being made1 see that the tube edges fit close up to the shoulder of the lugs all round1 and do not depend on the brass to fill up a badly fitted joint4 ,the chief things to observe are to make a sound joint the full depth of the lug1 and not merely to get a thin film of brass round the outer edge4 ,to do this1 the flame should be directed on to the thickest part of the lug first before getting the tube too hot1 and feeding the joint with borax before the metals get hot enough to scale4 ,as soon as the lug and tube begin to get a dull red1 feed with borax only1 then with brass and borax1 when it should flow almost like water and penetrate to the deepest part of the joint4 ,another very important thing is not to 8burn0 the tube by getting it too hot1 which will spoil it and cause an early fracture4 ,if the above method of heating the lug first is observed1 and the tube near the lug kept 8wet0 with borax to prevent it scaling1 this should not happen4 ,where the joint to be brazed lends itself to inside loading with the spelter1 the work should be so placed on the hearth that the brass inside1 when it melts1 will tend to flow to the outside of the joint4 ,then if borax only is used on the outside until brass appears round the edges1 it will be fairly certain that a sound joint will result4 ,as soon as this comes through1 feed a little brass-and-borax mixture to the joint1 and1 as soon as this melts1 stop the flame and remove from the hearth4 ,if the flame is kept on too long after this1 there is a possibility of 8soaking0 all the brass out of the joint1 especially so if the joint is not a very good fit4 ,some braziers use a blacklead mixture for protecting thin tubes whilst brazing2 but care must be taken to keep it out of the actual joint1 as brass will not adhere to metal where this is present4 ,cycle frame joints can be brazed on an ordinary smith's hearth1 but it is rather risky1 and requires more skill than with a gas blowpipe4 ,it also requires a good clear fire and a light blast4 ,the job should be kept well fed with borax to prevent the tubes scaling and burning4 ,the joint should be loaded from the inside with about a thimbleful or less of crushed borax and ,no4 #c spelter mixed in the proportion of about half of each in bulk4 ,the heaviest part of the lug should be heated first1 and the work must be turned frequently in the fire so as to avoid burning the tube4 ,if the joint is fed from the outside with borax until the brass flows round it1 a sound joint is ensured4 ,this applies to a joint where the lug is fitted inside the tube4 ,where the tube is fitted inside the lug1 a little brass and borax should be applied outside the joint just as the inside charge has melted1 which can be seen with some joints by looking down the inside of the tube4 ,when the tube is closed both ends1 such as the last joint of a frame1 the job is more difficult and requires careful judgment and skill to ensure a sound joint4 ,brazing ,cast-iron4--,although it has been dogmatically asserted both that cast-iron can and cannot be brazed1 it may be stated that the general results of attempting this process are so indifferent as to warrant the conclusion that this process cannot be recommended4 ,in brazing1 one of the conditions essential to success is that the metal to be brazed and the spelter should unite to form an alloy just where the brazing occurs1 and that this should take place spontaneously4 ,this actually happens when brazing copper1 brass1 wrought-iron1 etc41 but not in the case of cast-iron4 ,if1 however1 the reader desires to experiment in this direction1 the following hints may be useful4 ,first of all1 remove all dirt and grease from the cast-iron1 and then chemically clean it by immersion in hydrochloric acid1 afterwards well rinsing it in clean cold water4 ,a mixture of borax and water and spelter should now be applied where the brazing is required1 and gentle heat then brought to bear on it until the water is evaporated4 ,the heat should now be increased until the casting is red hot in the neighbourhood of the brazing2 and some workers claim that at this juncture the best results are obtained by dusting the red hot cast-iron liberally with boric or boracic acid powder4 ,a hard spelter should be used in preference to a readily fusible one1 otherwise the spelter would be fused much too soon1 and before the casting is raised to a sufficiently high temperature4 ,an experienced worker who believes that it is possible to make a sound joint in cast-iron by brazing1 states that he has brazed articles with equal parts of borax and boracic acid4 ,the chief difficulty is the flux4 ,he has tried one called 8,ferroment10 which seems to give good results4 ,the first casting brazed with it was #c in4 wide and #e_/h in4 thick1 and this casting at the time of writing had been in work six months for fifteen hours per day4 ,this same worker prefers to roast borax before use1 as it stops on the work better4 ,also1 when a deep1 wide joint is being dealt with1 he finds it an advantage to smear on a little clay underneath and the side1 as should the joint get slightly hotter in one part the spelter will run through and make an unsound joint4 ,the heat required to braze cast-iron varies somewhat with the spelter used4 ,if brazing by means of a smithy fire1 the spelter will show a blue flame when it starts to run1 and the article must then be removed from the fire4 ,in using a blowpipe or blowlamp1 the blue flame does not show1 and one has to look for the spelter melting1 and see that it flows well along the joint before removing the flame4 ,spelter which has been kept in stock a good time may not flow well4 ,the worker in question prefers brazing wire to grain spelter1 as by means of warming the end of the wire and dipping in the flux 7which will adhere to the hot wire71 it may be put just where desired4 ,he collects all the soft brass turnings from his lathe and uses them for brazing4 ,another worker has stated that those who have a forge of any kind will find the following an effective method of repairing an iron casting4 ,a flux may be made of chlorate of potash #d oz41 boracic acid #a lb41 and carbonate of iron #c oz4 ,these should be mixed well together and pounded4 ,the parts to be brazed together should be carefully cleaned by scraping them1 and brought to a bright-red heat4 ,then apply the flux and spelter and increase the heat4 ,still another worker says that in brazing cast-iron1 if powdered soda is used instead of borax1 the result will be a perfect joint4 ,,chapter ,,xi ,welding ,iron and ,steel under the ,hammer ,iron and steel can be joined by heating until they become plastic and then consolidating the two members of the joint by hammer blows1 the work being supported on an anvil4 ,correct heat and cleanliness are the chief requisites4 ,the 8welding heat0 corresponds with that temperature at which the metal is in a state of partial fusion on the surface4 ,the better the quality of the iron1 the higher the temperature it can stand without being burned and ruined4 ,iron at a welding heat gives off dazzling sparks1 whereas ordinary cast steel is only an intense yellow1 but few sparks being evolved4 ,sufficient lap for the proper making of the joint must always be allowed4 ,when heated in a perfectly clear fire1 the metal may need no treatment prior to hammering2 but otherwise it may be necessary to sprinkle sand or some special flux over the work4 ,at the proper moment the iron is transferred to the anvil1 and the union of the two members of the joint immediately effected2 delay means an imperfect joint4 ,in lifting the work out of the fire1 remove it vertically and so as not to collect particles of dirt on it4 ,keep a switch of brushwood at hand for removing adhering matter4 ,welding of ,steel ,specially ,considered4--,some steels will 8stand the fire0 better than others1 which means that they will stand more heat before they reach the point when they begin to burn4 ,the different kinds of steel used in a general way may be summed up as blister1 spring1 shear1 double shear1 and cast steel4 ,blister steel will1 as a rule1 stand the most heating before beginning to burn1 and the others follow in the order given4 ,the difference in heating will vary from nearly a white heat on blister to the yellow heat of cast steel4 ,a simple method of ascertaining what heat a steel will stand before beginning to burn is as follows3 ,heat the steel to its burning point1 and at various stages1 beginning at the yellow stage1 lay it on the anvil and give it a few blows with the hand hammer4 ,repeat the process until a heat is reached that will cause the steel1 when struck with the hammer1 to give off sparks like small fireworks4 ,when this stage is reached it will show that the burning point is arrived at4 ,careful observations of these points will enable the smith to know just when to begin to use the flux for welding1 which1 by the way1 must be just before the steel reaches the burning point4 ,another important point is the formation of the scarfs4 ,these should not be fullered down so thin or left in the same form as the scarfs as when joining iron1 and should be shorter 7compare ,a and ,b1 ,fig4 #ff74 ,illustration3 ,fig4 #ff4--,scarfs for ,iron and ,steel ,in bringing the steel up to its welding point1 care must be taken to have it at a uniform heat throughout at the part for welding2 and1 to get this1 the blast should not be forced at the start1 but used gently4 ,in some cases the blast should be stopped occasionally1 to allow the steel to soak4 ,then restart the blast1 and gradually force it when beginning to use the flux1 continuing so until the welding point is reached4 ,only light blows should be given at the start1 just to cause the two parts to stick together2 but when stuck1 the harder the blow the better the weld4 ,an idea seems prevalent that the flux has a certain influence on the steel1 and converts it into a form that makes it more weldable4 ,the real use of a flux in this case is simply to retard the heat1 and form a coat or shell on the steel1 and so counteract and prevent the burning action which takes place when heating steel in an ordinary blast fire4 ,the reason why different fluxes are required for different brands of steel is no doubt due to the differences in manufacture4 ,as a rule1 the greater the heat the steel will stand before burning1 the less it requires a flux to protect it1 so that in a great many cases a flux consisting of some clean1 sharp sand is all that is required2 but the steels that will burn at a lower heat require something more than sand to protect them4 ,hence arises the necessity of adding burnt borax1 crushed glass1 powdered marble1 etc4 ,the method of welding steel is as follows2 but before proceeding to get the heat make a point of having a shallow tin on the forge large enough to hold a sufficient quantity of the flux1 so that it will cover the scarfed end when being dipped in same4 ,have a clean fire and plenty of firing on the hearth1 so that the heat can be well covered4 ,start with gentle blast until the heat is nearly up to burning point4 ,if necessary1 stop the blast and let the heat soak for a few seconds so as to ensure a uniform heat4 ,gradually force the blast1 and keep withdrawing the 8heats0 and roll them well in the flux1 and so continue until it is thought that the heat is plastic enough to unite4 ,place the scarfs in position1 give a few light blows until the parts stick together1 then hammer well home and move smartly so as to ensure the proper joining together whilst in a plastic state4 ,when welded1 do not continue the hammering or tooling at too low a heat2 but if further hammering is necessary1 re-heat the work4 ,these hints are not applicable to every make of steel4 ,with the special steels manufacturers issue particular instructions4 ,a flux for welding cast steel consists of #b oz4 each of powdered chalk1 soda and burnt borax1 mixed with #a lb4 of silver sand4 ,a firm of steel manufacturers recommend a mixture of #ba oz4 of sand and #g oz4 of salt1 moistened2 the steel is to be treated in a fire of sulphurless coal4 ,,chapter ,,xii ,making ,blowpipes ,how to ,make a ,bench ,gas ,blowpipe4--,the blowpipe illustrated by ,fig4 #fg gives a powerful flame4 ,it can be clamped to the edge of the workbench by means of a winged nut1 a hole being made near the edge of the bench to accommodate the bolt4 ,a piece of hard wood ,a1 #e in4 by #b in4 by #a in4 thick1 has a strong iron bolt ,b passed through at one end4 ,a #b-;in4 cube ,c1 which should also be of good hard wood1 is screwed firmly to the other end of ,a1 the combined block being perforated through the centre to take a length of gas tube ,d1 which carries a gas-bracket with flange1 elbow joint1 and tap ,e4 ,the flange should be screwed down to the top of the block4 ,the elbow joint allows the direction of the flame to be adjusted within a wide range movement4 ,the arm of the bracket is removed1 and a shorter tube ,f1 #c in4 long1 is substituted4 ,this carries a #a_/b-;in4 iron ,t-piece ,g4 ,the tube ,h1 which is #c in4 long1 should be of brass1 threaded at one end to fit into the ,t4 ,illustration3 ,fig4 #fg4--;,bench ,gas ,blowpipe ,the air is conveyed through an #h-;in4 brass tube ,j #a_/d in4 in diameter1 which should be smooth inside4 ,this latter point is of some importance1 and1 if preferred1 a glass tube may be used instead of brass1 the current of cold air having a sufficient cooling effect to prevent undue heating4 ,the end should be cut off sharp with a file in the ordinary way and left in that condition4 ,smoothing the edge by fusion in a flame will not improve matters1 but rather the reverse4 ,of course1 the other end1 which comes outside1 must be smoothed to prevent injury to the indiarubber tube used for making connection with the bellows4 ,the air tube must be held firmly in the centre of the gas tube1 while capable of being moved in or out for the purpose of adjusting the flame4 ,this can be done quite satisfactorily by means of a short brass tube or nipple ,k1 threaded to screw into the ,t 7see ,fig4 #fg74 ,a sound cork should be driven into this short tube so as to entirely fill it1 a hole being made with a cork-borer to admit the air tube4 ,this hole must be exactly central1 and the cork must grip rather tightly4 ,a foot-bellows is generally used for supplying the air1 the bellows being connected with the air jet ,j by means of an indiarubber tube4 ,the tube ,d1 which should extend an inch or so below the bench1 is to be connected with the gas supply4 ,a ,simple ,gas ,blowpipe4--,a simple form of gas blowpipe is shown in ,fig4 #fh1 the rubber tube connecting it with the gas supply being fixed on the pipe at the point of connection with the cock4 ,to construct the appliance1 one end of a piece of brass gas pipe of the required length with1 say1 a #c_/h-;in4 bore1 is bent as shown1 whilst at the back of the curve thus made a hole is drilled to admit a tube ,a #e_/af in4 in diameter4 ,this should have one end 7see dotted lines7 bent to correspond with the angle previously formed in the larger tube1 whilst its other extremity should be bent upwards4 ,make these pipes red hot where they are to be bent1 and1 if they are afterwards plunged in cold water1 the material will to some extent be softened1 and its tendency to split will be obviated4 ,the smaller tube is passed through the hole in the bend of the larger one1 the ends being almost flush and quite concentric4 ,solder the parallel portions of the tubes together1 and then fix a gas-regulating cock to the larger one1 as in ,fig4 #fh4 ,the end is then connected to an ordinary bracket or burner by means of an indiarubber tube ,g1 and a short piece of tubing is fitted with a bone or other mouthpiece1 and attached to the projecting end of the air tube4 ,this instrument will do any soldering1 and will be suitable for melting gold1 silver1 and brass1 or brazing odd jobs in iron or steel4 ,of course1 when used for the last-named purpose it would be in conjunction with asbestos tubes or other supports4 ,illustration3 ,fig4 #fh4--,simple ,form of ,gas ,blowpipe ,illustration3 ,fig4 #fi4--,larger and more efficient ,blowpipe ,proportion of ,air to ,gas4--,as regards the relative volumes of gas and air for blowpipes1 the late ,mr4 ,thomas ,fletcher said that1 speaking roughly1 but still sufficiently near to make a correct rule by which to work1 a blowpipe requires one volume of gas to eight of air4 ,if the gas is supplied at a pressure equal to #a in4 of water1 and the air at eight times that pressure1 then1 to get the best effect1 the area of the gas and air pipes should be equal4 ,if the air supply is equal to #af in4 of water pressure1 the gas pipe must be double the area of the air1 and so on in proportion4 ,some makers assert that a better working flame is produced by using ten volumes of air to one volume of gas2 but1 of course1 if the blowpipe is fitted with taps1 the supplies can be adjusted easily4 ,it will be found1 however1 that any practical departure from ,fletcher's rule will result in a loss of power4 ,capacities of ,blowpipes4--,it has been said1 a blowpipe with a #a_/h-;in4 air jet1 if worked with an air pressure of #aj oz4 per square inch--that is1 #ae in4 of water--will braze up to about #a_/b lb4 total weight2 or in other words1 will securely unite two pieces of brass each weighing #a_/d lb4 ,with the same pressure a #a_/d-;in4 bore air-jet will braze a total weight of about #b lb41 and so on in proportion4 ,it will be understood that the air jet is measured at the point at which the blast leaves the air tube1 whilst the area of the gas supply is that of the annular space between the two tubes4 ,when the air tube is thus carried inside the gas tube 7see ,fig4 #fi71 the tool appears to be much larger than it really is1 and this accounts for the fact that a #a_/b-;in4 size blowpipe with the air tube fixed outside the gas supply is just as effective as one of the #c_/d-;in4 size which carry the air tube inside the stem4 ,all indiarubber tubing must be perfectly smooth inside1 for if it is wired or in any way rough1 the resultant friction will cause a loss of pressure4 ,it should also be of as large a bore as is convenient4 ,large and ,efficient ,blowpipe4--,a large and efficient blowpipe that can be made in a few minutes is shown by ,fig4 #fi1 the only materials required being a ,t-coupling and diminishing socket1 an elbow1 and one or two pieces of pipe4 ,the air tube ,a 7represented for the most part by dotted lines7 passes through the diminishing socket until it almost reaches the nozzle of the blowpipe1 with which it is concentric4 ,by using the elbow ,d1 the two supply pipes are brought parallel to each other1 so that the indiarubber connecting tubes can be more easily held in the hand like reins1 as by simply squeezing them the flame can be readily regulated4 ,sometimes1 in cases of emergency1 a plug drilled to meet the air tube is used in place of the socket4 ,the plug is thrust into the end of the ,t-socket2 but in all cases it must be airtight4 ,this blowpipe can be used efficiently only in conjunction with a foot blower4 ,,chapter ,,xiii ,managing ,blow-lamps ,the stoves and lamps burning paraffin in the form of vapour have become very popular on account of their good heating properties1 portability1 and little attention required4 ,they consist of a container holding paraffin1 a burner with a heating tube attached is screwed to the container1 and a tube leading almost to the bottom4 ,a small air-tube1 similar to a cycle-pump1 is fixed in container1 the handle and cap only being in sight4 ,when the burner tubes are heated1 a thumbscrew on the filler caps is closed1 and a few strokes of the pump puts a slight pressure on the oil in the container4 ,the oil is forced up the central tube to the burner2 but before reaching this it has to flow round the heating coils1 and in so doing is turned to vapour4 ,the outlet at the nipple being very small1 causes the vapour to issue with some force1 and it mixes with the air1 forming a mixture which burns with a non-luminous flame similar to that of a bunsen burner4 ,this flame plays on the heating coils1 and once started1 the lamp is practically automatic2 a stroke or two from the pump will keep it going until the oil is consumed4 ,there are patterns that use petrol or benzol1 their action being slightly different4 ,petrol and benzol are light spirits1 which give off inflammable vapour at a much lower heat than paraffin does4 ,advantage is taken of this fact by causing burner and nipple to be in one solid brass casting1 so that when the nozzle is heated1 the brass conducts the heat back to the nipple and so vaporises the petrol1 which is fed to the nipple by a thick wick contained in a tube which reaches almost to the bottom of the container1 the wick touching the bottom4 ,to start either paraffin or petrol lamps1 the exit tube or nozzle is heated4 ,the petrol lamp has no coils round the nozzle2 but comes straight from the holder to the exit nipple4 ,the size of flame is regulated by a needle valve fitted with a wood or fibre handle4 ,the petrol lamp has no pump1 except on high-power brazing lamps whose use requires expert handling4 ,the chief trouble with lamps using paraffin is that the burner becomes choked2 this is shown by the lamp jumping out or the flame not attaining sufficient heat4 ,the makers supply a proper cleaning needle1 a sheet stamped to form a handle and a piece of fine steel wire fixed at one end4 ,nothing else1 such as pins1 etc41 should be used1 or the hole in the nipple becomes enlarged1 and emitting too much gas1 causes a smoky flame4 ,the cleaner should be used each time before lighting4 ,a good way to avoid this trouble is to use a small funnel with fine brass gauze soldered in the body when filling4 ,white ,rose is a quite satisfactory oil for these lamps4 ,after considerable use the heating coil becomes choked with carbon deposit4 ,a new heater tube can be obtained1 or the old one cleaned by drilling two or three holes in the ends and passing a piece of flexible wire 7such as ,bowden brake wire7 through the heater and removing the obstruction4 ,after getting it clean1 tap out the holes and fix suitable screws1 flat under the head1 with a piece of asbestos to make a tight joint4 ,if a larger flame is not obtained by pumping1 take the cap off the pump and draw out the plunger2 the leather is probably worn4 ,fit a new one2 or it may have become hard1 in which case apply a little oil and open out carefully4 ,the retaining valve is in the centre of the pump bottom1 and is removed by using a long key down the pump barrel4 ,the valve is in four pieces4 ,see that the spring is free and that the cork is in good condition4 ,when replacing1 take care not to get it cross thread1 and screw firmly home4 ,the washer under the filler cap is of rubber and cuts through in time4 ,do not use pliers to screw down2 it will go gas-tight with the fingers if the washer is good4 ,to remove the nipple from which the gas issues is almost impossible without a proper key4 ,this has a universal joint1 which allows it to be rotated1 although the handle is almost at right angles with the burner4 ,keys and all other parts mentioned can be obtained from any dealer in these lamps4 ,with the lamps using petrol1 the only parts requiring attention are the plate from which gas issues and the wick4 ,unlike the paraffin nipple1 this is a circular stamping of brass approximately #c_/d in4 in diameter with a fine hole in the centre4 ,to remove this disc1 pass a long flat screwdriver blade through two openings in the nozzle and turn to the left 7anti-clockwise71 holding the body of the lamp firmly on the bench4 ,before fitting a new disc1 thoroughly clean recess and remove any deposit from the inside of the valve box4 ,unscrew the needle and gland if there is any leak there1 and clean and repack with asbestos yarn4 ,a little glycerine on the packing appears to be an advantage4 ,place the disc in position1 dip an asbestos washer in water1 and screw the nozzle firmly down4 ,the wick inside the lamp filters the spirit before reaching the nipple and occasionally needs replacing4 ,remove the cap from the bottom of the lamp1 and with a piece of thick wire flattened at one end and filed to a hook1 push it up the tube and withdraw the old wick4 ,the new one is simply put in its place and the cap screwed tight4 ,the washer under the filled cap is of cork and rarely gives any trouble4 ,,chapter ,,xiv ,making ,blow-lamps ,a ,paraffin ,brazing ,blow-lamp4--,the brazing blowlamp shown in ,fig4 #gj was made at a total cost of less than #ds4 ,the illustration is printed to a scale of about one-quarter full size4 ,the lamp illustrated is not a mere experiment1 as the writer of this description had a similar one in use for over two years1 and during that time brazed hundreds of jobs with its aid4 ,the container is of tinplate1 and adapted from a workman's tea can4 ,when purchased this will have a wire handle and two hinges1 and these should be removed and soldered up4 ,the handle shown at ,h is made from a strip of iron1 #a_/h-;in4 by #e_/h-;in4 section1 bent round to the shape shown and riveted to the side of the container4 ,these rivets should be well soldered over inside to prevent leakage4 ,the joint of the longer strip is shown at ,x4 ,the lid should next be taken in hand1 a #e_/af-;in4 hole being drilled at one side close to the handle1 to take an ordinary ,lucas cycle valve4 ,a leather washer is fitted inside1 and also one outside under the lock nut1 the latter being then tightly clamped up4 ,at ,e is shown the filling cap1 the body part of which was taken from an old paraffin oil-lamp container1 and the screw cap made at the local brass works2 but this fitting can be obtained in a finished state from many model-fittings manufacturers4 ,this is soldered to the lid in the position shown1 a hole being afterwards drilled in the tin to suit it4 ,illustration3 ,fig4 #gj4--,paraffin ,brazing ,blow-lamp1 the container being shown in section ,the cock shown at ,d is an ordinary gas-cock1 with a length of #c_/h-;in4 outside-diameter copper piping screwed and sweated in beneath4 ,this is passed through a hole drilled in the lid for its reception1 and the base of the cock is then sweated in position4 ,note that the length of this pipe is such that when the lid is in place it clears the container bottom by #a_/h in4 ,the coil of piping at ,p is #c_/h in4 diameter copper tube coiled round to the shape shown1 the lower end being tightly screwed into the top of the cock4 ,the opposite end is screwed for a short length of #c_/h-;in4 gas thread1 and very tightly fitted with a screw plug such as that used by plumbers for shutting off a portion of gas piping4 ,before screwing this on1 a small hole about #a_/cb in4 in diameter should be drilled in the middle of same2 this is the nipple for the exit of gas to the burner4 ,the #c_/h-;in4 copper tubing should not require filling with anything before bending2 this operation is best done round a mandrel of wood4 ,no heating is necessary4 ,a certain amount of flattening of the tube will no doubt occur1 but this is immaterial4 ,the end of the flame tube is1 of course1 open1 otherwise the flame could not emerge4 ,the nipple end of the flame tube is also quite open1 with the nipple end of the coil just projecting inside4 ,the portion of tubing shown dotted in ,fig4 #gj takes the vapour from the coils to the nipple2 it does not pass through the coils1 but at the back of them1 and bends round as shown4 ,the lid of the container should now be carefully soldered down all round1 and then the #c_/af-;in4 brass stay rod shown at ,s must be fitted and both ends sweated over4 ,it is essential that this stay is not omitted1 as otherwise the pressure to which the container is subjected would bulge out the ends4 ,the flame tube ,a should now be made of #a_/cb-;in4 sheet-iron1 being held in place by two or three clips riveted on and bent over the coil ends as shown at ,c1 only one of which is shown for clearness4 ,the flame tube does not taper1 nor is the back end closed up4 ,its diameter should be #a-a_/d in4 and length #c-a_/b in41 but this depends on the size of the hole in the nipple4 ,no holes are required in this tube1 as all the air is drawn in at the end4 ,the nipple has a gas thread cut inside it1 and it is screwed tightly on to the end of the copper coil4 ,the length of the pipe from tap to coil is not important2 about #i in4 will be satisfactory4 ,the best means of joining the nipple to the tube is to screw the end of the tube before bending it round at the end1 and then to screw the nipple on tightly4 ,the pipe can afterwards be bent as shown4 ,the jet hole in the nipple should be about #a_/cb in4 bare1 and should be so drilled that the issuing gas passes through the centre of the flame tubes4 ,the tube is open at both ends1 to allow air to be drawn down and complete the combustion of the paraffin vapour1 the mixture igniting and burning properly when the vapour passes out at the other end and comes into contact with the atmosphere4 ,to use the lamp1 it should be filled about two-thirds or one-half full of paraffin oil1 and the container cap then screwed hard down with a leather cap as a washer4 ,a cycle pump should then be connected to the valve ,v1 and a few strokes given1 the cock ,d being meanwhile closed4 ,the copper coil should next be put into a gas flame or the fire for a few minutes until nearly red hot1 and then the cock ,d should be opened a shade1 which will allow the paraffin to rise up the pipe ,i and enter the coils ,p1 where it will become vaporised1 and the gas will then issue from the nozzle ,n1 and burn at the mouth of the coils4 ,the lamp may then be applied to the job1 and five or six more strokes given to the pump1 when the flame should burn with an intense heat and give out a roaring noise4 ,the theory of action of lamps of this character is as follows3 ,the pressure of air in the container forces the paraffin up the copper tube into the coil1 where it is vaporised by the red-hot piping4 ,the vapour then issues at some pressure from the nipple hole and1 passing down the flame tube1 an ejector action is caused which draws air in with it4 ,this air mingles with the paraffin vapour1 and when the mixture issues at the other end1 and comes into contact with more air1 combustion takes place4 ,the heat produced by the lamp should be quite sufficient to braze the bottom bracket of a motor-cycle frame and other similar jobs4 ,the size of nipple with relation to the size of the flame tube is most important4 ,if the flame tube be too large in proportion1 the result is an excess of air1 which cools the gas unduly and the flame dies out4 ,a candle is put out in a draught from the same cause4 ,on the other hand1 if the flame tube is too small1 or the nipple hole too large1 the result is an excess of gas1 causing incomplete combustion and a partly luminous and smoky flame1 with less heating power4 ,to ascertain if the nipple hole is too small1 take a strip of tin and1 whilst the lamp is burning1 hold the tin partly over the end of the flame tube1 so as to restrict the amount of air entering1 and note the result4 ,if the drawing 7,fig4 #gj7 be regarded as #d in4 to #a ft41 and the lamp made accordingly1 it will be of ample size to braze small and model boilers4 ,it must be understood1 though1 that the size of the lamp alone does not govern the size of the flame1 this depending entirely on1 firstly1 the size of the nipple1 and secondly1 the pressure of air in the container forcing the vapour out4 ,the larger the container1 the longer the lamp will burn without refilling1 and1 incidentally1 the larger it is the weaker the container will be1 and vice versa4 ,should this lamp be required for brazing and silver-soldering articles about #a_/b in4 in diameter1 it must be altered1 as it is obviously much too large4 ,the same container will do1 of course1 although perhaps rather unwieldy4 ,if preferred1 another container just half the size could be made2 this will be handier in use1 although it will not allow the lamp to burn for so long a period without recharging as the larger pattern4 ,for the tubing1 #c_/af-;in4 copper tube1 preferably solid drawn1 will be suitable4 ,this should be heated to a dull red and then quenched in water to anneal it1 this making the task of bending it much simpler4 ,if it kinks too much in the bent portions1 pour some molten resin into the tube1 one end being plugged up for this purpose1 and when set1 bend to the shape desired4 ,the resin can be heated and run out afterwards4 ,the flame tube may be half the diameter and length of the one illustrated1 but no hard and fast rule can be given for the dimensions of this part of the lamp1 as the size of the nipple hole has everything to do with this4 ,make the latter just big enough to admit a fine needle4 ,a simple method is to drill the cap almost through1 and then punch the rest through with the point of a needle4 ,by experimenting1 it will be easy to find the right proportions of flame tube and nipple hole4 ,the screwed joints should be a metal-to-metal fit as it is termed1 that is1 they should fit so tightly when screwed home that no leakage is possible4 ,this can be ensured by seeing that all male threads are a tight fit in their respective holes4 ,,chapter ,,xv ,electric and ,thermit ,welding ,briefly ,considered ,contact ,welding4--,the electric welding of iron strips and sheets is usually done by the ,thomson process of 8contact-welding40 ,in this process the metal is brought to a welding heat by passing a very large current through the joint to be welded1 which1 by virtue of its high resistance in relation to other parts of the circuit1 develops great local heat4 ,when the correct temperature for welding is reached1 the joint is pressed together by mechanical means1 and the current interrupted4 ,in ,fig4 #ga the necessary arrangements for the welding of a steel rim are sketched4 ,a is the iron core of an alternating current transformer and ,b the primary winding supplied with alternating current either from a works dynamo or a public supply1 and controlled by a double-pole switch ,c4 ,the transformer has a secondary winding consisting of a single copper strip of very heavy section ,d1 in which secondary currents of low voltage but very large volume are induced4 ,this winding ,d terminates in two heavy metal clamps ,e1 one fixed and the other capable of movement by rack and pinion or screw1 and the clamps must be shaped to the contours of the work ,f they are intended to hold1 so as to fit well and present as little electrical resistance there as possible4 ,the butt ends of the wheel rim are brought into contact1 current switched on at the transformer primary1 and immediately a very heavy secondary current passes round the 8winding0 ,d1 generating intense heat at the junction of the metal rim ,g held in the clamps1 where the electrical resistance is comparatively high4 ,in a few moments the joint will arrive at welding heat and the screw feed is then operated1 driving the joint together and completing the weld1 except so far as a little hand dressing may be found necessary4 ,directly the weld is established the current is switched off at the mains and the job allowed to cool out4 ,nothing less than #e kilowatts to #aj kilowatts is likely to be very satisfactory for hoops about #c_/d in4 by ,no4 #af gauge1 and the current must be alternating4 ,the primary voltage and frequency is immaterial1 as the transformer can be wound to suit the circuit conditions whatever they may be4 ,illustration3 ,fig4 #ga4--;,electric ,contact ,welding of ,steel ,rim ,the method of welding by resistance1 that is1 by raising locally the welding point to the temperature required by bringing the two surfaces into contact until their high resistance produces a welding heat and then squeezing them together1 is by far the most manageable and satisfactory commercial process of the two electrical processes4 ,it is adapted for 8spot-welding0 or producing local adhesions between metal plates after the manner of riveting1 for butt or end-on welds1 for seams1 chains1 rings1 etc41 and automatic welding machines are now made that can deal with no less than #a1ejj welds and upwards per hour with semi-skilled labour1 with the least possible percentage of failures and a very low cost for electrical energy4 ,alternating current is essential with this type of weld1 and is used to energise a step-down transformer of special construction4 ,arc ,welding4--,notwithstanding the superiority of the resistance welding process to most commercial work1 particularly that of a small kind necessitating rapid repeat work1 the 8arc0 method1 which has been in use for many years1 and was probably the first experimented with1 has now become largely used on work where it was thought impossible to adapt it a few years ago4 ,the system is extensively employed in iron and steel works1 shipyards1 and boiler works1 and the class of work it is employed on varies from the dismantling of iron and steel buildings1 by fusing and cutting through the structural ironwork and girders1 to the filling up of blowholes in castings4 ,the metal to be welded is connected to one pole1 and the electrode handled by the operator forms the other pole1 an arc being struck between the two4 ,broken castings and forgings can be satisfactorily repaired by running new fused metal round them4 ,recently the arc system has been applied with success for making welds on tramway rails1 the resistance of the welded joint being found very much lower than when made with the usual fishplates and bonded joints4 ,continuous current gives better results than alternating for the arc system1 and a generator designed for use with this process has a 8drooping characteristic10 that is1 the volts at the terminals fall rapidly with an increase in the current output4 ,in this way the current is automatically limited to some extent1 when the short-circuiting effect of the operation comes into play4 ,successfully to weld by this process a current of #cjj to #ejj amperes at #hj volts is necessary1 and every precaution has to be taken to protect the workman from the intense glare of the arc4 ,thermit4--,thermit is an aluminium alloy whose combustion generates so much heat that the substance can be used for the welding of iron and steel4 ,it is the patented invention of ,dr4 ,hans ,goldschmidt4 ,with thermit as a means of melting and welding1 and with the use of special clamps and devices1 a number of operations1 otherwise difficult1 can be performed1 and thermit has come into general use for repairing broken or defective parts4 ,by the use of a portable jacket and clamp1 the joints of gas1 water1 and steam pipes may be welded with the pipes in position2 and the advantages of such a material to an engineer far removed from supplies and repair shop1 as at sea1 can hardly be enumerated4 ,new journals have been welded to heavy rolls1 broken pump-rods have been joined1 and a number of structural parts successfully united by its aid4 ,thermit is made up as follows3 ,iron oxide is intimately mixed up with about one-third as much in weight of powdered aluminium1 according to the equation ,fe#b ,o#c #b ,al ,al#b ,o#c #b ,fe4 ,the metals to be united are placed together and surrounded by a little clay or similar substance and the mixture is placed all around the joint4 ,the mixture is fired by a little magnesium1 and the chemical change that follows creates such an intense heat that iron is readily welded4 ,when the joint is cold and cleaned up it is hardly perceptible4 ,according to instructions published by ,thermit1 ,ltd41 it is of the utmost importance that the moulds1 crucibles1 etc41 should be kept thoroughly dry1 and they may advantageously be warmed before use to ensure the absence of any dampness4 ,the parts to be welded must previously be brought to red heat1 which is best effected by means of a gas and air flame4 ,the proper design of the mould is of the utmost importance4 ,it should have a runner and riser1 and the metal should be allowed to flow between as well as around the ends of the pieces to be welded4 ,the expense and inconvenience of making wooden patterns may be obviated by making the model of wax1 ramming the sand round this1 and subsequently melting out the wax4 ,,chapter ,,xvi ,oxy-,acetylene ,welding ,of late years oxy-acetylene welding and cutting have made great strides1 and have placed at the disposal of the metal-working trades a means of doing many things that hitherto were impossible4 ,purified acetylene and oxygen1 both under pressure1 are supplied to a special blowpipe or torch4 ,the flame in its hottest part has a temperature of about #d1jjj ,c4 and is therefore sufficiently high to melt any metals with which it may be brought into contact4 ,the torch is fitted with all necessary adjustments to vary the supply of either of the gases1 and constitutes a handy tool with which the intelligent worker soon acquires great dexterity4 ,in a special form of the torch there is a means of introducing a further supply of compressed oxygen1 which makes it possible for the blowpipe flame to cut its way rapidly through thick metal1 the particles of which are actually consumed in the path of the oxygen4 ,it is out of the question in a single chapter of a handbook covering such a large scope as the present work to do more than indicate some of the uses to which the oxy-acetylene torch or blowpipe may be put4 ,this chapter is obviously no attempt whatever at providing a complete working guide to oxy-acetylene welding4 ,all that will be here attempted is to present a brief description of a typical outfit and some notes on working the blowpipe1 and then to give some practical instruction from the pen of an oxy-acetylene welder on the treatment of copper1 aluminium and cast-iron4 ,it may here be pointed out that there is now a large number of firms specialising in the manufacture of oxy-acetylene welders' appliances1 and most of them publish illustrated catalogues which anyone proposing to equip himself for oxy-acetylene welding would do well to obtain4 ,the source of the oxygen used in welding is now always cylinders1 which are obtainable in various sizes1 either by purchase or on hire from the gas-compressing companies1 to whom they have to be returned for recharging4 ,the acetylene also can be had in the compressed form1 but in this case the gas is not simply compressed into steel cylinders because1 if it were1 any simple shock would be likely to cause explosion4 ,the acetylene is therefore dissolved in liquid acetone1 the cylinders containing some porous substance such as fossil meal1 which is saturated with the acetone and the acetylene then pumped in4 ,these also can be bought or hired from the gas-compressing companies4 ,a tremendous amount of welding is done1 however1 with acetylene generated on the spot1 and there are on the market quite a number of approved appliances that can be recommended1 the best form of generator being that in which the calcium carbide is dropped into the water instead of the water dripping into the charge of calcium carbide4 ,it is essential that the gas be purified before use4 ,as most people doubtless know1 acetylene is one of the hydro-carbon series of gases and is evolved by the action of water on calcium carbide1 a substance which is one of the products of the electric furnace4 ,illustration3 ,fig4 #gb4--;,diagram of ,oxy-acetylene ,welding ,apparatus ,the particulars and instructions on pp4 #acf to #aci are due to the ,acetylene ,corporation1 ,ltd4 ,fig4 #gb presents a diagrammatic illustration of a complete oxy-acetylene blowpipe equipment with the exception of the acetylene generator and holder1 which apparatus may be placed in any suitable position 7preferably outside7 at any reasonable distance from the blowpipe4 ,a is an ordinary gas tap connecting the hydraulic back pressure valve ,b with the acetylene supply pipe from the acetylene holder4 ,the blowpipe is connected at valve ,c by means of a flexible tube with the outlet tap ,d of the hydraulic back-pressure valve4 ,this forms the acetylene supply pipe to the blowpipe4 ,the blowpipe is connected at valve ,e by means of a special canvas-covered strong rubber pipe with the outlet tap ,f of the oxygen pressure regulator1 which is fixed1 as shown1 on the oxygen cylinder4 ,g is a pressure gauge4 ,this pipe conveys the oxygen supply to the blowpipe1 and should be securely attached1 as it is subject to pressures varying from #e lb4 to #dj lb4 per sq4 in4 ,the hydraulic back-pressure valve should have been previously charged with water1 and the gas regulator screwed into the oxygen cylinder4 ,the blowpipe apparatus is now ready for use1 with the taps ,a and ,d closed and the taps ,c1 ,e and ,f open4 ,first1 slowly open the oxygen cylinder valve 7not shown7 with the key supplied for that purpose4 ,by means of the thumb-screw ,h1 adjust the gas pressure to the correct working pressure for the blowpipe used4 ,the approximate pressure of oxygen required for each blowpipe is as follows3 ,no4 #b1 #h lb4 per sq4 in42 ,no4 #c1 #aj lb42 ,no4 #d1 #aa lb42 ,no4 #e1 #ab lb42 ,no4 #f1 #ad lb42 ,no4 #g1 #af lb42 ,no4 #h1 #ai lb42 ,no4 #aj1 #bj lb42 ,no4 #ab1 #be lb42 ,no4 #ae1 #cj lb4 ,then open the acetylene taps ,a and ,d1 and when acetylene is unmistakably smelt at the nozzle of the blowpipe1 ignite the gases by means of a gas jet1 candle1 or taper4 ,then by means of the tap ,c slowly throttle down the acetylene until the small white cone of flame at the nozzle of the blowpipe shows a clearly defined outline4 ,as some indication of the correct size of the cone1 it may be mentioned that when working with the ,no4 #aj blowpipe this should be about #a_/d in4 diameter by #e_/h in4 long4 ,this cone in the other blowpipes is greater or less according to the relative size4 ,the tap ,a must never be used to regulate the supply of acetylene2 in fact1 after the hydraulic back-pressure valve has been charged with water1 it is best to leave this tap always on4 ,the working pressure for oxygen previously given should not be too rigidly adhered to4 ,even in the same sizes of blowpipes the conditions must vary slightly1 and a little practical experience with each blowpipe will soon indicate the best working conditions4 ,if the flame is not properly regulated it may fire back and go out4 ,if so1 the taps ,c and ,e should be shut off at once1 and a few seconds allowed to elapse before relighting4 ,when work is carried on for a long time at a stretch and the burner becomes warm1 it will be found necessary to slightly open the acetylene tap ,c from time to time4 ,if work is being done which involves the nozzle of the blowpipe being held in a confined space1 it is advantageous to cool this end of the blowpipe by immersing it from time to time in a bucket of water4 ,while this is done the gases must be turned off at ,c and ,e4 ,welding should be done at the apex or outer extremity of the small white cone4 ,if the hole in the nozzle of the blowpipe gets obstructed at any time through beads of iron being splashed into it1 or from any other cause1 it may be cleared with a piece of copper wire and cleaned with a wire brush4 ,no steel reamer or other sharp instrument should be used in the hole1 which otherwise will be altered in size4 ,on stopping work the acetylene tap ,c should be closed first and then the oxygen tap ,e4 ,when work is completely stopped1 the oxygen cylinder should be shut off4 ,the oxygen cylinder valve should never be opened until taps ,f and ,e are open1 and it should then be opened slowly4 ,in this way sudden impact of oxygen in the regulator is obviated4 ,the following instructions on the methods of welding copper1 cast-iron and aluminium are contributed by a foreman welder4 ,welding ,copper4--,copper to be welded should have its edges bevelled to enable the welding to penetrate the entire thickness of the metal4 ,bevelling is not generally practised below a thickness of #c_/cb in4 ,from #c_/cb in4 to #c_/af in41 a slight open bevel is sufficient2 #c_/af in4 thick and over1 the angle of the bevel should be about #ij4 ,it is not necessary to go beyond this even with great thickness4 ,the bevelling should be regular1 especially at the bottom1 so as not to produce holes or excess of thickness at the bottom of the bevel4 ,the edges to be welded and their immediate neighbourhood should be thoroughly cleaned4 ,this can be done with a file1 scraper1 or sheets of emery4 ,chemical agents such as spirits of salt or nitric acid are sometimes employed2 but it is preferable to precede their use by a mechanical cleaning4 ,before beginning the welding the parts should be carefully arranged so that during the welding operation they remain perfectly in position4 ,owing to the high conductivity of copper1 a relatively larger blowpipe tip must be used than when welding either iron or mild steel of the same thickness4 ,the power of a blowpipe of #bbe litres with an approximate consumption of #gge cub4 ft4 of acetylene per hour would be suitable1 with economical results1 for iron or mild steel #a_/h in4 thick1 whereas for copper of the same thickness the power of the blowpipe should be of #cjj litres1 having an approximate consumption of #aje cub4 ft4 of acetylene per hour4 ,also1 a blowpipe which is too strong tends to melt the metal too rapidly4 ,this should be as carefully avoided as that of melting too slowly4 ,a pure copper welding rod may be employed for filling in1 but it is not so effective as a welding rod made of phosphor copper4 ,the phosphorus is incorporated in a very small quantity1 so that none remains in the weld after its execution4 ,a filler rod which contains too much phosphorus lacks fluidity1 and melts at a temperature much lower than that of the copper to be welded1 thus facilitating adhesion4 ,moreover1 the welds in which the phosphorus remains lack elongation1 and therefore do not possess the same mechanical properties as pure copper4 ,the welding rod after #a_/af in4 of its diameter should be about equal to the thickness of the weld1 although in practice feeders about #a_/d in4 in diameter are not generally employed4 ,welds made on copper without a deoxidising welding rod properly prepared have a tendency to oxidise1 and therefore do not possess the required qualities4 ,in addition1 the surface of the metal must be covered with a carefully prepared mixture of potassium phosphate and potassium carbonate to a depth of about #a_/af in4 ,upon the application of the flame1 the mixture will melt and form a glaze over the surface of the copper1 thus preventing oxidation and assuring good work4 ,a flux consisting of chloride of sodium1 sodium borate1 and boracic acid is also recommended4 ,the flux should be sparingly applied by dipping the end of the welding rod into the vessel containing the flux4 ,the end of the rod should be warmed in order that the flux adheres4 ,before beginning the actual operation of welding1 it is essential to raise the edges of the weld and the parts in the vicinity to a high temperature4 ,the high conductivity of the metal necessitates this1 as any supply of molten welding rod before the edges are in a molten state inevitably produces adhesion4 ,the flame of the blowpipe should be perfectly regulated and maintained without excess of either acetylene or oxygen4 ,in executing the weld1 care must be taken to avoid contact of the white jet of the blowpipe flame with the metal just about to be melted4 ,the distance of the white jet should vary according to the power of the blowpipe1 say from #c_/af in4 to #c_/h in4 ,if this distance is increased1 the gases resulting from the second phase of combustion1 carbonic acid and water vapour1 influence the weld4 ,care must be taken that the fusion of the metal should not be undertaken until the edges of the weld and the parts near have been raised to a high temperature4 ,at this moment the welding rod and the parts to be joined should be melted simultaneously4 ,it is essential that the welding rod should be regularly incorporated in the line of welding1 and must not be allowed to fall in drops4 ,the operation should be continuous1 taking care to attack regularly the two edges of the metal4 ,the welding is thus executed rapidly4 ,it is well known that internal strains are always set up in every process of welding1 due to the expansion and contraction when a metal is heated and cooled4 ,copper lacks tenacity when heated2 hence contraction of the metal1 whose coefficient of expansion is also fairly high2 fractures thereby are often produced1 especially in the welded part4 ,however1 pre-heating the article to a high temperature1 maintaining the heating after the operation of welding and slow cooling1 enables one in many cases to avoid fractures due to contraction4 ,it is also necessary to hammer the line of welding and its vicinity4 ,after the hammering operation it is essential to reheat the copper1 raising it to redness 7#ejj ,c4 to #fjj ,c474 ,then plunge into cold water1 or cool as rapidly as possible4 ,the structure of the weld is not quite as homogeneous as other parts of the piece welded4 ,this is1 however1 controlled largely by the skill and workmanship of the operator1 who can1 at will1 make the weld more or less homogeneous4 ,it is impossible to enumerate in anything like detail all the work in copper which may be executed by oxy-acetylene autogenous welding4 ,however1 copper-smiths are advantageously making great use of the system1 thereby replacing their old methods of brazing and riveting4 ,welding ,aluminium4--,in preparing aluminium to be welded1 the edges must first be thoroughly cleaned and the welding rod very pure1 so as to avoid the incorporation of impurities1 which is apt to bring about rapid disintegration in the line of welding4 ,bevelling the edges to be joined is not necessary below a thickness of #a_/h in4 ,from #a_/h in4 to #c_/af in4 a slight open bevel is sufficient1 #c_/af in4 thick and above angle of bevel should be about #ij4 ,for thin sheets up to a maximum of #c_/cb in41 welding is facilitated by flanging the edges at right angles4 ,the depth of the flange should be slightly deeper than the thickness of the metal4 ,by this method no welding rod is required1 the edges being simply fused4 ,the weld should afterwards be hammered level4 ,aluminium should never be welded without a flux4 ,if welding is attempted without a flux1 globules consisting of aluminium within and a coating of alumina 7oxide of aluminium7 will appear4 ,in order to eliminate these by the blowpipe flame it would be necessary to raise the temperature to the melting point of the oxide of aluminium1 which is nearly #c1jjj ,c41 whilst the melting point of metallic aluminium is only #feg ,c4 ,to produce a flux which will dissolve the oxide at the low melting point of the metal and at the same time protect the hot metal from contact with the air has obviously not been a simple problem to the chemist and engineer4 ,however1 several good fluxes are now obtainable which enable any experienced welder to effect satisfactory welds in aluminium4 ,a flux consisting of the following ingredients can be recommended3 sodium chloride #cj parts1 potassium chloride #de parts1 lithium chloride #ae parts1 potassium fluoride #g parts1 and bisulphate of potassium #c parts4 ,when making fluxes for the welding of aluminium1 great care is necessary in order to completely dry the ingredients1 thus avoiding their combination with each other4 ,on aluminium above #c_/cb in4 thick1 the flux is best applied by dipping the end of the welding rod into the vessel containing the flux4 ,the end of the rod should be first warmed in order that the flux adheres4 ,the welding rod after #a_/af in41 its diameter should be just about equal to the thickness of the weld1 although in practice feeders above #a_/d in4 diameter are not advisable4 ,in executing the weld1 care must be taken to avoid contact of the white jet of the blowpipe flame with the metal just about to be melted1 because the high temperature of this part tends to produce holes which are difficult to fill in4 ,the distance of the white jet should vary according to the power of the blowpipe1 say from #a_/d in4 to #c_/d in4 ,the flame should be so adjusted as to furnish an excess of acetylene4 ,there need be but little fear of carbonising the metal1 for the reason that the temperature of the work is comparatively low4 ,for thin welds1 up to #a_/h in4 thick1 it is preferable to hold the welding rod in front of the blowpipe in the direction of the edges to be welded4 ,as soon as the latter begins to melt it is heated rapidly1 and should be lowered to form one molten bath with the metal of the piece4 ,the welding is thus done very rapidly4 ,for great thicknesses it is preferable to obtain fusion of the welding rod1 previously heated in the molten bath of the bevel4 ,directly after welding1 the weld should be thoroughly washed in clean warm water in order to remove all remaining traces of the flux1 which would otherwise continue to have a chemical action on the metal1 thereby setting up corrosion4 ,welding ,cast-,iron4--,the edges of the weld should be bevelled when the thickness exceeds #a_/h in42 this enables the welding to penetrate the entire thickness of the metal4 ,both edges must be bevelled to an angle of #de1 so as to form a right angle at the weld4 ,the bevelling should be regular1 especially at the bottom1 so as not to produce holes or excess thickness at the bottom of the bevel4 ,workers who attempt to effect welds on cast-iron above1 say1 #a_/d in4 in thickness1 without bevelling1 invariably obtain poor results1 as it is impossible to get regular and thorough penetration4 ,the bevelling of the edges may be done by chipping or grinding1 etc4 ,grinding wheels made from a carbide of silicon abrasive are very effective for cast-iron4 ,the edges to be welded and their immediate neighbourhood must be free from sand1 dirt1 and rust4 ,it is known that internal strains are always set up in every process of welding1 due to the expansion and contraction when a metal body is heated and cooled4 ,these strains are not unavoidable1 but their effect may be minimised or nullified4 ,in the case of cast-iron1 the tendency to crack will be greatly increased if the cooling of the metal after fusion is rapid or irregular4 ,consequently1 the article to be welded should be pre-heated slowly to about #gjj ,f4 to #a1jjj ,f4 ,generally speaking1 the higher the temperature of pre-heating1 the less the danger of cracking4 ,preferably1 pre-heating and subsequent slow cooling should be carried out in a muffle1 particularly where light and intricate castings have to be dealt with4 ,in all cases care should be taken in the selection of the proper size of blowpipe tip to be used on any particular job4 ,therefore1 the size of tip recommended by the manufacturers should be employed4 ,the total heat of fusion of cast-iron being high1 it is necessary to use a blowpipe with a greater power than for the same thickness of welds on mild-steel or wrought-iron4 ,in the actual operation of welding1 the blowpipe flame should be played on the edges to be welded until the melting of the iron just takes place4 ,it is essential to avoid contact of the white cone of the blowpipe flame with the metal just about to be melted2 the point should be kept at a distance varying from #c_/af in4 to #c_/d in41 according to the thickness of the work4 ,the two edges to be joined should melt simultaneously4 ,as soon as the first fusion is obtained1 a little flux or scaling powder must be added2 this is usually applied by dipping the extremity of the welding rod into the vessel containing the flux1 the rod having been previously heated4 ,avoid throwing the powder into the molten metal whilst executing the weld1 as the supply from the welding rod is always sufficient4 ,many kinds of fluxes for cast-iron are furnished by the manufacturers of welding apparatus1 which vary considerably in composition4 ,the principle of all of them is to provide some chemical which1 at the high temperature involved1 will break up the oxide into its component parts4 ,the following combinations will perform these functions1 and can be recommended3 7#a7 ,boracic acid #hj parts1 powdered chlorate of potash #bj parts1 ferric carbide #ae parts4 7#b7 ,equal parts of carbonate and bicarbonate of soda1 to which is added from #aj to #ae per cent4 of borax and #e per cent4 of precipitated silica4 7#c7 ,carbonate of soda #ej per cent4 and bicarbonate of soda #ej per cent4 ,the necessity for using a flux may not be thoroughly appreciated2 but if it is attempted to weld cast-iron without it difficulty will at once be experienced4 ,do not add any metal from the welding rod until the bottom of the ,v is filled from the sides4 ,it is found that by employing silicon in the welding rod1 in the form of ferro-silicon1 the iron combines with the silicon in preference to the carbon1 allowing the carbon to take the form of graphite1 and thus facilitate the formation of grey iron4 ,the welding rod should contain about #d per cent4 of silicon and as low as possible in manganese4 ,the purchase of such a welding rod is not at all difficult1 and may be obtained from the same manufacturers as the flux1 from #a_/h in4 to #a_/b in4 in diameter4 ,one criticism of cast-iron welding has been directed against the hardness of the weld4 ,this hardness may be due to a number of causes1 such as inefficiency of the operator1 unsatisfactory fluxes and welding apparatus1 rapid cooling1 etc4 ,therefore1 as stated previously1 in order to get good workable welds1 there must be slow cooling after the welding is complete2 and there is no reason why the worker who carefully follows the instructions given1 and applies himself diligently to the task1 should not be able to weld cast-iron of any thickness in an efficient and workmanlike manner4 ,this method of welding cast-iron successfully solves an unlimited variety of manufacturing and repair problems in the engineering industry1 and can be relied on to make homogeneous welds on cast-iron4 ,it is impossible to enumerate in anything like detail all the work in cast-iron which may be executed by oxy-acetylene welding2 but the following are some of the applications for which it has already been advantageously employed3 ,for repairing broken machine parts1 gear boxes1 motor cylinders1 crank cases1 tanks1 manifolds1 flywheels1 etc41 filling blowholes and defects in castings4 ,castings impossible or difficult to mould can be made in parts and united4 ,teeth broken from gear wheels can be renewed1 and adding metal in any desired quantity to worn parts of cast-iron articles4 ,as a concrete example of its economical and positive aid to the engineering industry1 the following may be of interest4 ,a cast-iron belt-wheel would have gone on the scrap heap1 a total loss1 with four of the six spokes broken1 three entirely out4 ,it was #e ft4 in diameter1 and weighed about #ejj lb41 but was not worth much as scrap metal4 ,scrapping it meant the purchase of a new wheel1 and perhaps a long delay in getting one cast4 ,but with the oxy-acetylene process the three spokes that were fractured were welded into place2 the fourth spoke broken near the hub was also welded4 ,there were seven welds1 each about #a-a_/b in4 by #d in42 the job was done profitably at a cost of #e1 ready for delivery in two days1 and was considerably better than buying a new wheel1 and waiting two weeks or two months for delivery4 ,the process is particularly suitable for this class of work1 and cannot fail to give satisfaction if performed by an experienced welder4 ,the cost of welding a given job depends not only on its thickness1 but on the skill of the workman4 ,for example1 the same class of job may vary as much as #ej per cent4 if executed by different operators4 ,,chapter ,,xvii ,lead ,burning ,lead-burning or flaming is the autogenous welding of lead by means of either an aero-hydrogen or oxy-coal-gas blowpipe flame4 ,in the past the apparatus required included a hydrogen-gas generating chamber 7called the 8lead-burning machine07 and a blower or air chamber4 ,the hydrogen was made by the action of dilute sulphuric acid on zinc4 ,that system is now1 or should be1 obsolete1 having been superseded by the cleanly and altogether more convenient process of employing two cylinders1 one of compressed coal-gas and the other of compressed oxygen1 in conjunction with an injector-pattern blowpipe4 ,gauges and regulators are required as in the oxy-acetylene process4 ,the oxy-acetylene process may be successfully applied to lead-burning in spite of the great heat of such a flame4 ,the consumption of acetylene1 according to ,mr4 ,d4 ,richardson's translation of ,granjon and ,rosenberg's ,french work1 is only #a to #b cubic feet per hour for lead #a_/af in4 to #c_/af in4 thick1 and the process is stated to have 8considerable advantages over all other methods of autogenous soldering40 ,in lead-burning it is customary to employ a triangular stick of refined lead for filling up the seams4 ,by being burnt or joined together in this way1 the lead becomes homogeneous1 and the various parts of it equally withstand the same chemical action and heat4 ,for this reason it is used for joining the seams of chemical and acid tanks1 and for the joints of pipes used for the conveyance of such chemicals4 ,solder being an alloy1 the acid would have a solvent action on it1 eating it away and rendering it useless1 and it would also give rise to electrical action1 practically impossible when only one metal is exclusively employed4 ,lead-burning is also often used on external or roof work4 ,the seams burnt on sheet-lead are of two kinds3 one forming a butted joint1 the other a lapped joint4 ,in burning a butted seam1 the two edges of the lead to be joined are butted together1 and shaved about #a_/d in4 to #c_/h in41 or slightly less1 on each side4 ,the gas and oxygen are turned on and adjusted so as to produce a flame from about #e in4 to #f in4 long1 and tapering to a fine point4 ,the hottest part of the flame is the centre of the thickest portion1 about #a in4 or #a-a_/b in4 from the jet4 ,hold the jet in the right hand1 and a strip of lead in the left1 and allow the flame to play on the end of the strip1 which is held just above the seam4 ,as the strip melts1 the jet is diverted on to the seam so as to fuse the edges together1 the additional lead forming a thickened portion4 ,the strip is again melted1 and joined to the edges1 and also to the thickest part2 and so on along the length4 ,care should be taken to burn the lead through1 but not for the metal to flow beneath the seam4 ,after a little practice1 the operator will know exactly when to apply and when to remove the jet4 ,fig4 #gc shows a flat butted joint partly burnt4 ,the stick of lead is just nipped with the flame1 and a bead of lead dropped on the seam4 ,the flame is then directed on to this bead until it is fused with the seam4 ,when bead and seam are melted together1 the flame is immediately raised4 ,the next bead of lead is then dropped on the seam so as to half cover the previous bead1 as shown at ,m 7,fig4 #gc74 ,the flame is then directed on the second bead1 the flame being immediately raised after these are fused together1 and this operation is repeated until the whole of the seam is burnt4 ,a flat lapped joint1 partly burnt1 is shown by ,fig4 #gd4 ,in burning this joint1 the stick of lead is only required to fill up any irregularities in the burning1 and is not required to form the seam in the same way as it is in a butted joint1 because in lapped burning the overcloak is burnt down on to the undercloak1 as shown in ,fig4 #ge4 ,in horizontal and vertical burning1 lapped joints only should be used4 ,fig4 #ge shows a specimen of horizontal or side burning1 and ,fig4 #gf one of vertical or upright burning4 ,in burning both of these1 the stick of lead is not required at all1 the overcloak being in each case burnt down on to the undercloak4 ,care must be taken that both the overcloak and undercloak of a lapped joint are well shaved4 ,illustration3 ,fig4 #gc4--;,butted ,seam ,partly ,burnt ,illustration3 ,fig4 #gd4--,lapped ,seam ,partly ,burnt ,illustration3 ,fig4 #ge4--;,horizontal or ,side ,burning ,illustration3 ,fig4 #gf4--,vertical or ,upright ,burning ,illustration3 ,fig4 #gg4--;,burning ,upright ,joint ,illustration3 ,fig4 #gh4--;,branch ,joint ,ready for ,burning ,the seams should not be soiled or greased1 and care must be taken not to tarnish them in any way4 ,if the lead is not shaved quite clean1 or it becomes tarnished after it is shaved1 it will be found difficult to burn it together successfully4 ,no tallow or smudge is necessary4 ,the operator will soon detect the presence of any foreign substance or dirt on the lead1 and the shavehook should be kept handy to remove it4 ,in burning a vertical lapped seam1 starting at the bottom1 the lapping lead is melted1 and as it runs is turned on to the back portion and fused into it4 ,a slight projection is formed1 which holds the next melting1 and so on1 each layer forming a base for the next1 and adding to the height until the top is reached4 ,in practising either horizontal or vertical burning1 the student should first place his work at an easy angle--say1 at about #be or #cj--;gradually raising it as he becomes proficient until the seam is in a horizontal or vertical position as desired4 ,two surfaces can be burned together in any position--horizontal1 vertical1 or even overhead1 where soldering would be impossible4 ,pipe joints can also be made by burning4 ,first one pipe is opened to form a socket like a slip joint4 ,the male part1 which must enter at least #c_/d in41 must be well shaved and made to fit tight4 ,fig4 #gg shows an upright joint prepared and partly burnt4 ,fig4 #gh shows a section of a branch joint as prepared for burning4 ,care must be taken to work up a good thick shoulder for the socket ,n4 ,,index ,acetylene used in welding1 #ace ,alloys1 eutectic1 #d ,aluminium1 bit used with1 #fa ----1 difficulty in soldering1 #eg1 #eh ----1 flux for1 #fa1 #adc1 #add ----1 oxy-acetylene welding1 #adc ----1 soldering1 #fb1 #fc ---- solders1 #eh-fa ,arc welding1 #aca1 #acb ,autogenous welding 7see ,oxy-acetylene welding7 8,best0 solder1 #d ,birdcage wires1 soldering1 #ec ,bismuth1 solder and flux for1 #g ,black1 plumber's1 #ff-fh ,blow-lamp bit1 #ba ,blow-lamps1 #dd1 #df1 #ib ----1 managing1 etc41 #aah-aba ----1 paraffin brazing1 #abb-abh ,blowpipe1 bench1 #dj1 #da ----1 ,black's1 #cg ---- capacities1 #aaf ---- flame1 #ch ----1 ,fletcher's1 #cg ----1 gas1 making1 #ic1 #id ----1 mouth1 #cg-dj ----1 operating1 #df ----1 oxy-acetylene1 #acf ----3 proportion of air to gas1 #aad ---- soft solder1 #d ---- soldering1 #ag1 #df-ef ,boiling water1 solders that melt in1 #aa ,borax flux1 #gh1 #gi ,brass fittings1 tinning1 #ff ----1 solder and flux for1 #g ----1 soldering aluminium to1 #fj ,britannia metal1 solder and flux for1 #g ,brazing1 #a1 #hi-ajg ---- copper rod1 #ajj ---- cycle-frame joints1 #ajc ----1 flux for1 #ia ---- iron1 #ih-ajj1 #aje-ajg ---- key stems1 #aja ----1 spelter for1 #hi-ia ---- steel1 #ih-ajj ,brazing-lamps 7see ,blow-lamps7 ,brooches1 soldering1 #hc ,brush for applying flux1 #ad ,bunsen burner1 #dj1 #db ,burning lead1 #b1 #aej-aed ,cast-iron1 brazing1 #aje-ajg ----1 flux for1 #ajf1 #ajg1 #adg ----1 oxy-acetylene welding1 #ade ,catching-tray1 #db ,churns1 soldering1 #ce ,clay1 packing work in1 #ea ,cloths1 plumber's1 #fh1 #fi 8,coarse0 solder1 #d 8,common0 solder1 #d ,compo4 piping1 making solder from1 #i ,contact welding1 #abi-aca ,copper1 brazing1 #ajj ----1 flux for1 #ada ----1 oxy-acetylene welding1 #aci ----1 soldering aluminium to1 #fj ----1 soft solder and flux for1 #g ,copper-bit soldering1 #bh-cf ,copper-bits1 #ag-bd ----1 gas-heated1 #bb-bd ----1 holding1 #cj ----1 spirit-heated1 #bj1 #ba ----1 stoves for1 #bd1 #be ----1 tinning1 #be-bh ,corroded metal1 soldering1 #ej ,cycle brazing1 #ajb-aje ,dial ring1 soldering1 #ej ,dross on solder1 #aa ,electric arc welding1 #aca1 #acb ---- contact welding1 #abi-aca ,enamelled ware1 soldering1 #ce ,eutectic alloys1 #d 8,fine0 solder1 #d ,flaming lead1 #b1 #aej-aed ,flux 7see also names of metals7 ----1 applying1 #ad1 #ae ---- for brazing1 #ia ---- combined with solder1 #aj ---- containers1 #ad ---- for soft soldering1 #ab-af ,fluxite and specialities1 #ac1 #bj ,food containers1 flux for1 #ae ,fusion welding 7see ,oxy-acetylene welding7 ,galvanised steel1 solder and flux for1 #g ,gas blowpipes1 #da1 #ic1 #id1 #aab-aag ---- brazing-hearth1 #id-ih ,gas-heated bits1 #bb-bd ,gold1 8colouring10 #hg1 #hh ----1 flux for1 #g ---- jewellery1 soldering1 #hc-hh ---- solders1 hard1 #he1 #hf ---- ----1 soft1 #g ,gold-cased ware1 soldering1 #hd ,granulated solder1 #h ,gun-barrel1 soldering catch on1 #cf ,gunmetal1 solder and flux for1 #g ,hard solder and soldering 7see ,brazing1 ,silver-soldering1 and names of metals7 ,hardness of solder1 #e ,hearth1 gas brazing1 #id-ih ,hiorns1 ,a4 ,h41 #d1 #e ,iron1 brazing1 #ih-ajj1 #aje-ajg ----1 flux for1 #adg ----1 hammer-welding1 #ajh ----1 oxy-acetylene welding1 #ade ----1 soft solder and flux for1 #g ,jewellery1 soldering1 #hc-hh ,joints1 reinforced and filled-in1 #cd ,jubb1 ,w4 ,h41 #gf ,kettle spout1 soldering1 #ej ,key stems1 brazing1 #aja 8,killed spirit10 #ab-ae ,lading-can handle1 soldering1 #dg ,ladle1 solder1 #g ,lamp1 soldering lug on1 #dh ,lead1 solder and flux for1 #g ,lead-burning1 #b1 #aej-aed ,leaded lights1 soldering1 #ce 8,magic0 solder1 #aj 8,medium0 solder1 #d ,melting points of solder1 etc41 #d1 #e ,milk churns1 soldering1 #ce ,name-plates1 sweating letters on1 #ed-ef ,oxy-acetylene welding1 #b1 #acd-adi ---- ---- aluminium1 #adc-ade ---- ----3 apparatus1 #acf-aci ---- ---- cast-iron1 #ade-adi ---- ---- copper1 #aci-adc ,oxygen used in welding1 #ace ,paillons1 solder1 #gi-hj ,pewter1 making solder from1 #i ----1 solder and flux for1 #g ,phosphor-tin1 solders containing1 #ei-fa ,pickle1 gold-solderer's1 #he1 #hg ----1 silver-solderer's1 #gg1 #gh1 #hg ,pipe joints1 burnt1 #aec1 #aed ---- ----1 horizontal or underhand wiped1 #fi-gb ---- ----3 lead to cast-iron1 #gd ---- ----1 silver-soldered1 #hj1 #ha ---- ----1 soldered1 #eb1 #ec ---- ----1 upright wiped1 #gb-gd ,plumber's black1 #ff-fh ---- cloths1 #fh1 #fi ---- flux1 #ff ---- solder1 #d1 #fd-ff 8,poisoned0 solder1 #f1 #fe1 #ff ,rings1 jewelled1 soldering1 #hd ,ryan's gas-heated bit1 #bb ,sal-ammoniac block for tinning bits1 #bf-bh ,sand1 packing work in1 #ea ,seams1 soft-soldered1 #ca-cc ,shave-hook1 #bh ,silver jewellery1 soldering1 #hc ----1 soft solder and flux for1 #g ---- solders1 #ge-gg ,silver-soldering1 #a1 #c1 #ge-hb ----3 pickle1 #gg1 #gh ----3 quenching1 #ha ----3 removing marks1 #ha ,smudge1 plumber's1 #ff-fh ,soft soldering1 #a-c1 #bh-ef ---- ---- with blowpipe1 #df-ef ---- ---- ---- copper-bit1 #bh-cf ---- solders1 #d-aa ---- ---- that melt in boiling water1 #aj1 #aa ,soil1 plumber's1 #ff-fh ,solder 7see also ,silver solder1 ,soft solder1 etc41 and under names of metals7 ---- combined with flux1 #aj ----1 overheated1 #aa ----1 re-melted1 #aa 8,soldering iron10 #ag ,soldering solutions1 #ad ,spelter1 #a1 #c1 #hi-ia ,spirit-heated bits1 #bj1 #ba ,spirit-lamps1 #dj ,spot-welding1 electric1 #acj ,steel1 brazing1 #ih-ajj ----1 flux for1 #aaa ----1 hammer-welding1 #aji-aaa ----1 soft solder and flux for1 #g ,stoves for heating bits1 #bd1 #be ,strip solder1 #f-h ,sweating1 #cb-cd1 #ed-ef ,tapers1 #da ,tears1 solder1 #h ,thermit welding1 #b1 #acb1 #acc ,tin1 solder and flux for1 #g ,tinning bits1 #be-bh 8,tinol0 specialities1 #aj1 #ac1 #ai ,tinplate1 solder and flux for1 #g 8,touch0 or tallow1 #ff ,tube solder1 #aj ,vegetable masher1 soldering1 #dh 8,very fine0 solder1 #d ,watch-case1 silver-soldering1 #gi ,welding 7see also separate headings7 ----1 electric1 #abi-acb ---- iron and steel under the hammer1 #ajh-aaa ----1 oxy-acetylene1 #acd-adi ----1 thermit1 #acb1 #acc ----3 various processes1 #a1 #b ,wire1 solder1 #h ,zinc chloride1 #ab-ae ---- in solder1 #f1 #fe1 #ff ----1 solder and flux for1 #g ,,printed ,,by ,,cassell ,,company1 ,,limited1 ,,la ,,belle ,,sauvage1 ,,london1 ,e4,c4 ,transcriber's ,notes ,inconsistencies in the source document have been retained4 ,depending on the hard- and software used1 not all elements may display as intended4 ,page #ei1 table3 the row ,tin #f does not add up to #ajj 71 presumably7 as the other rows do4 ,minor obvious punctuation errors have been corrected silently4 ,page #e3 #ff and #cd have been changed to #ff and #cd1 respectively4 ,page #g3 flow over the hoe has been changed to flow over the hole4 ,page #aed3 enter at last has been changed to enter at least4