Lead Burning
Lead-burning or flaming is the autogenous welding of lead by means of
either an aero-hydrogen or oxy-coal-gas blowpipe flame. In the past the
apparatus required included a hydrogen-gas generating chamber (called
the “lead-burning machine”) and a blower or air chamber. The hydrogen
was made by the action of dilute sulphuric acid on zinc. That system is
now, or should be, obsolete, having been superseded by the cleanly and
altogether more convenient process of employing two cylinders, one of
compressed coal-gas and the other of compressed oxygen, in conjunction
with an injector-pattern blowpipe. Gauges and regulators are required as
in the oxy-acetylene process.
The oxy-acetylene process may be successfully applied to lead-burning in
spite of the great heat of such a flame. The consumption of acetylene,
according to Mr. D. Richardson’s translation of Granjon and Rosenberg’s
French work, is only 1 to 2 cubic feet per hour for lead 1/16 in. to
3/16 in. thick, and the process is stated to have “considerable
advantages over all other methods of autogenous soldering.”
In lead-burning it is customary to employ a triangular stick of refined
lead for filling up the seams. By being burnt or joined together in
this way, the lead becomes homogeneous, and the various parts of it
equally withstand the same chemical action and heat. For this reason it
is used for joining the seams of chemical and acid tanks, and for the
joints of pipes used for the conveyance of such chemicals. Solder being
an alloy, the acid would have a solvent action on it, eating it away and
rendering it useless, and it would also give rise to electrical action,
practically impossible when only one metal is exclusively employed.
Lead-burning is also often used on external or roof work.
The seams burnt on sheet-lead are of two kinds: one forming a butted
joint, the other a lapped joint.
In burning a butted seam, the two edges of the lead to be joined are
butted together, and shaved about 1/4 in. to 3/8 in., or slightly less,
on each side. The gas and oxygen are turned on and adjusted so as to
produce a flame from about 5 in. to 6 in. long, and tapering to a fine
point. The hottest part of the flame is the centre of the thickest
portion, about 1 in. or 1-1/2 in. from the jet. Hold the jet in the
right hand, and a strip of lead in the left, and allow the flame to play
on the end of the strip, which is held just above the seam. As the strip
melts, the jet is diverted on to the seam so as to fuse the edges
together, the additional lead forming a thickened portion. The strip is
again melted, and joined to the edges, and also to the thickest part;
and so on along the length. Care should be taken to burn the lead
through, but not for the metal to flow beneath the seam. After a little
practice, the operator will know exactly when to apply and when to
remove the jet.
Fig. 73 shows a flat butted joint partly burnt. The stick of lead is
just nipped with the flame, and a bead of lead dropped on the seam. The
flame is then directed on to this bead until it is fused with the seam.
When bead and seam are melted together, the flame is immediately raised.
The next bead of lead is then dropped on the seam so as to half cover
the previous bead, as shown at M (Fig. 73). The flame is then directed
on the second bead, the flame being immediately raised after these are
fused together, and this operation is repeated until the whole of the
seam is burnt.
A flat lapped joint, partly burnt, is shown by Fig. 74. In burning this
joint, the stick of lead is only required to fill up any irregularities
in the burning, and is not required to form the seam in the same way as
it is in a butted joint, because in lapped burning the overcloak is
burnt down on to the undercloak, as shown in Fig. 75. In horizontal and
vertical burning, lapped joints only should be used.
Fig. 75 shows a specimen of horizontal or side burning, and Fig. 76 one
of vertical or upright burning. In burning both of these, the stick of
lead is not required at all, the overcloak being in each case burnt down
on to the undercloak. Care must be taken that both the overcloak and
undercloak of a lapped joint are well shaved.
[Illustration: Fig. 73.--Butted Seam Partly Burnt]
[Illustration: Fig. 74.--Lapped Seam Partly Burnt]
[Illustration: Fig. 75.--Horizontal or Side Burning]
[Illustration: Fig. 76.--Vertical or Upright Burning]
[Illustration: Fig. 77.--Burning Upright Joint]
[Illustration: Fig. 78.--Branch Joint Ready for Burning]
The seams should not be soiled or greased, and care must be taken not to
tarnish them in any way. If the lead is not shaved quite clean, or it
becomes tarnished after it is shaved, it will be found difficult to burn
it together successfully. No tallow or smudge is necessary. The operator
will soon detect the presence of any foreign substance or dirt on the
lead, and the shavehook should be kept handy to remove it.
In burning a vertical lapped seam, starting at the bottom, the lapping
lead is melted, and as it runs is turned on to the back portion and
fused into it. A slight projection is formed, which holds the next
melting, and so on, each layer forming a base for the next, and adding
to the height until the top is reached.
In practising either horizontal or vertical burning, the student should
first place his work at an easy angle--say, at about 25° or
30°--gradually raising it as he becomes proficient until the seam is in
a horizontal or vertical position as desired. Two surfaces can be burned
together in any position--horizontal, vertical, or even overhead, where
soldering would be impossible.
Pipe joints can also be made by burning. First one pipe is opened to
form a socket like a slip joint. The male part, which must enter at
least 3/4 in., must be well shaved and made to fit tight. Fig. 77 shows
an upright joint prepared and partly burnt. Fig. 78 shows a section of a
branch joint as prepared for burning. Care must be taken to work up a
good thick shoulder for the socket N.
INDEX
Acetylene used in welding, 135
Alloys, eutectic, 4
Aluminium, bit used with, 61
----, difficulty in soldering, 57, 58
----, flux for, 61, 143, 144
----, oxy-acetylene welding, 143
----, soldering, 62, 63
---- solders, 58-61
Arc welding, 131, 132
Autogenous welding (_see_ Oxy-acetylene welding)
“Best” solder, 4
Birdcage wires, soldering, 53
Bismuth, solder and flux for, 7
Black, plumber’s, 66-68
Blow-lamp bit, 21
Blow-lamps, 44, 46, 92
----, managing, etc., 118-121
----, paraffin brazing, 122-128
Blowpipe, bench, 40, 41
----, Black’s, 37
---- capacities, 116
---- flame, 38
----, Fletcher’s, 37
----, gas, making, 93, 94
----, mouth, 37-40
----, operating, 46
----, oxy-acetylene, 136
----: proportion of air to gas, 114
---- soft solder, 4
---- soldering, 17, 46-56
Boiling water, solders that melt in, 11
Borax flux, 78, 79
Brass fittings, tinning, 66
----, solder and flux for, 7
----, soldering aluminium to, 60
Britannia metal, solder and flux for, 7
Brazing, 1, 89-107
---- copper rod, 100
---- cycle-frame joints, 103
----, flux for, 91
---- iron, 98-100, 105-107
---- key stems, 101
----, spelter for, 89-91
---- steel, 98-100
Brazing-lamps (_see_ Blow-lamps)
Brooches, soldering, 83
Brush for applying flux, 14
Bunsen burner, 40, 42
Burning lead, 2, 150-154
Cast-iron, brazing, 105-107
----, flux for, 106, 107, 147
----, oxy-acetylene welding, 145
Catching-tray, 42
Churns, soldering, 35
Clay, packing work in, 51
Cloths, plumber’s, 68, 69
“Coarse” solder, 4
“Common” solder, 4
Compo. piping, making solder from, 9
Contact welding, 129-131
Copper, brazing, 100
----, flux for, 141
----, oxy-acetylene welding, 139
----, soldering aluminium to, 60
----, soft solder and flux for, 7
Copper-bit soldering, 28-36
Copper-bits, 17-24
----, gas-heated, 22-24
----, holding, 30
----, spirit-heated, 20, 21
----, stoves for, 24, 25
----, tinning, 25-28
Corroded metal, soldering, 50
Cycle brazing, 102-105
Dial ring, soldering, 50
Dross on solder, 11
Electric arc welding, 131, 132
---- contact welding, 129-131
Enamelled ware, soldering, 35
Eutectic alloys, 4
“Fine” solder, 4
Flaming lead, 2, 150-154
Flux (_see also names of metals_)
----, applying, 14, 15
---- for brazing, 91
---- combined with solder, 10
---- containers, 14
---- for soft soldering, 12-16
Fluxite and specialities, 13, 20
Food containers, flux for, 15
Fusion welding (_see_ Oxy-acetylene welding)
Galvanised steel, solder and flux for, 7
Gas blowpipes, 41, 93, 94, 112-117
---- brazing-hearth, 94-98
Gas-heated bits, 22-24
Gold, “colouring,” 87, 88
----, flux for, 7
---- jewellery, soldering, 83-88
---- solders, hard, 85, 86
---- ----, soft, 7
Gold-cased ware, soldering, 84
Granulated solder, 8
Gun-barrel, soldering catch on, 36
Gunmetal, solder and flux for, 7
Hard solder and soldering (_see_ Brazing, Silver-soldering, _and names
of metals_)
Hardness of solder, 5
Hearth, gas brazing, 94-98
Hiorns, A. H., 4, 5
Iron, brazing, 98-100, 105-107
----, flux for, 147
----, hammer-welding, 108
----, oxy-acetylene welding, 145
----, soft solder and flux for, 7
Jewellery, soldering, 83-88
Joints, reinforced and filled-in, 34
Jubb, W. H., 76
Kettle spout, soldering, 50
Key stems, brazing, 101
“Killed spirit,” 12-15
Lading-can handle, soldering, 47
Ladle, solder, 7
Lamp, soldering lug on, 48
Lead, solder and flux for, 7
Lead-burning, 2, 150-154
Leaded lights, soldering, 35
“Magic” solder, 10
“Medium” solder, 4
Melting points of solder, etc., 4, 5
Milk churns, soldering, 35
Name-plates, sweating letters on, 54-56
Oxy-acetylene welding, 2, 134-149
---- ---- aluminium, 143-145
---- ----: apparatus, 136-139
---- ---- cast-iron, 145-149
---- ---- copper, 139-143
Oxygen used in welding, 135
Paillons, solder, 79-80
Pewter, making solder from, 9
----, solder and flux for, 7
Phosphor-tin, solders containing, 59-61
Pickle, gold-solderer’s, 85, 87
----, silver-solderer’s, 77, 78, 87
Pipe joints, burnt, 153, 154
---- ----, horizontal or underhand wiped, 69-72
---- ----: lead to cast-iron, 74
---- ----, silver-soldered, 80, 81
---- ----, soldered, 52, 53
---- ----, upright wiped, 72-74
Plumber’s black, 66-68
---- cloths, 68, 69
---- flux, 66
---- solder, 4, 64-66
“Poisoned” solder, 6, 65, 66
Rings, jewelled, soldering, 84
Ryan’s gas-heated bit, 22
Sal-ammoniac block for tinning bits, 26-28
Sand, packing work in, 51
Seams, soft-soldered, 31-33
Shave-hook, 28
Silver jewellery, soldering, 83
----, soft solder and flux for, 7
---- solders, 75-77
Silver-soldering, 1, 3, 75-82
----: pickle, 77, 78
----: quenching, 81
----: removing marks, 81
Smudge, plumber’s, 66-68
Soft soldering, 1-3, 28-56
---- ---- with blowpipe, 46-56
---- ---- ---- copper-bit, 28-36
---- solders, 4-11
---- ---- that melt in boiling water, 10, 11
Soil, plumber’s, 66-68
Solder (_see also_ Silver solder, Soft solder, etc., _and under names
of metals_)
---- combined with flux, 10
----, overheated, 11
----, re-melted, 11
“Soldering iron,” 17
Soldering solutions, 14
Spelter, 1, 3, 89-91
Spirit-heated bits, 20, 21
Spirit-lamps, 40
Spot-welding, electric, 130
Steel, brazing, 98-100
----, flux for, 111
----, hammer-welding, 109-111
----, soft solder and flux for, 7
Stoves for heating bits, 24, 25
Strip solder, 6-8
Sweating, 32-34, 54-56
Tapers, 41
Tears, solder, 8
Thermit welding, 2, 132, 133
Tin, solder and flux for, 7
Tinning bits, 25-28
“Tinol” specialities, 10, 13, 19
Tinplate, solder and flux for, 7
“Touch” or tallow, 66
Tube solder, 10
Vegetable masher, soldering, 48
“Very fine” solder, 4
Watch-case, silver-soldering, 79
Welding (_see also separate headings_)
----, electric, 129-132
---- iron and steel under the hammer, 108-111
----, oxy-acetylene, 134-149
----, thermit, 132, 133
----: various processes, 1, 2
Wire, solder, 8
Zinc chloride, 12-15
---- in solder, 6, 65, 66
----, solder and flux for, 7
PRINTED BY CASSELL & COMPANY, LIMITED, LA BELLE SAUVAGE, LONDON, E.C.
Transcriber’s Notes
Inconsistencies in the source document have been retained.
Depending on the hard- and software used, not all elements may display
as intended.
Page 59, table: the row Tin 6 does not add up to 100 (%, presumably)
as the other rows do.
Minor obvious punctuation errors have been corrected silently.
Page 5: 66° and 34° have been changed to 66% and 34%, respectively.
Page 7: flow over the hoe has been changed to flow over the hole.
Page 154: enter at last has been changed to enter at least.
End of Project Gutenberg's Soldering, Brazing and Welding, by Bernard E. Jones