noted that soldering and soldering tackle should be kept as far away from other work (and iron and steel goods and tools) as possible.
A pointed wooden stick is not a good tool for applying killed spirit, because the acid acts on the wood, which becomes unpleasant to handle, and the liquid does not leave the wood readily enough to place the right quantity on the exact spot to be soldered. A galvanised iron wire is better. Another good tool is a thin steel or iron “spit,” about 12 in. long, and a steel knitting-needle is also excellent. Should a brush be preferred, take a few hairs from a broom, place them in one end of a thin metal tube, and then flatten the end with a blow from a hammer.
A brush made by hammering the ends of a short length of cane until the fibres are like bristles is frequently used for the purpose, the handle end being soaked in molten wax before using the cane brush the first time.
Fig. 1.—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 perfumes, and to push a length of thick galvanised iron wire through the orifice in the stopper, leaving about 11⁄2 in. projecting above. The lower end should just reach the bottom of the bottle, and may be flattened and pointed. The lead nipple is squeezed round the wire to hold it firmly, and the projecting end bent into a ring to form a handle, as shown in Fig. 1. The cork part should be thinned a little to render it an easy fit in the bottle neck. The flux can be quickly applied with the wire exactly where it is wanted, and in very small quantity; for a long seam the wire can be run along with one dip in the solution. The fingers need not be brought into contact with the flux; the cork will not go soft and will not sink down owing to the lead flange supporting it.
Flux Used on Food Containers.
—Killed spirits is objectionable as a flux for soldering vessels intended to contain food of any kind. Not only is this flux a poison, but it is liable to produce subsequent rusting wherever used unless all traces of it are thoroughly removed immediately after soldering. A good non-poisonous flux suitable for tin boxes may be made by dissolving resin in oil. Place a quantity of powdered resin in an iron vessel, add colza, olive, or any similar oil, and apply gentle heat, meanwhile stirring it until the resin is dissolved. Dissolve as much resin in the oil as possible without making the flux too thick (when cold) to apply with a brush. One or two small experiments will soon decide the required proportions. The resin is really the base of the flux; but the oil is added to facilitate its application and removal before and after the soldering process.
CHAPTER IV
Soft-soldering with the Copper Bit
Choice between Blowpipe and Bit.—The method of heating depends on the size of the work, or rather the area to be soldered, and the conveniences at the command of the worker. The soldering bit, although so commonly used, is not necessarily the best for the beginner to use for small work. A blowpipe flame—from a bunsen burner or a spirit lamp—is far more convenient and neat, and its effects can be applied and localised with the greatest precision, down to the merest pin point of heat applied at a definite spot. The bit is chiefly useful for long joints such as in tinplate work, and for pieces bound together to which the bit is applied to heat up and melt solder between them. But for work where the soldering area does not measure more than an inch or so (and there is a vast amount of this kind), the blowpipe flame is far preferable. It must be admitted, though, that this is a matter in which some workmen might have two distinct opinions; and, as already remarked, the bit is far more commonly used.
Fig. 2.—Soldering Bit
Fig. 3.—Pivoted Soldering Bit
Copper Bits.
—The soldering bit or bolt (miscalled an “iron”) carries a pointed lump of copper at the end (Fig. 2), riveted in, or alternatively, in small sizes, screwed on to the shank. Some bits are pivoted (see Fig. 3) to enable them to point at various angles for dealing with difficult situations.
A home-made bit (Figs. 4 and 5) may be made by drilling and tapping a short length of 11⁄2-in. or 2-in. square copper to receive the screwed end of a rod of 5⁄16-in. iron, the copper being afterwards heated and drawn to a point or to a blunt edge as preferred. This forms a good bit for most ordinary purposes. An axe-head or hatchet bit is shown in Fig. 6; the copper bolt is riveted in the eye of the iron rod, the bit, however, being free to revolve, as this is essential when making joints in heavy lead pipe, for which purpose it is principally used. Fig. 5 represents a bit which is a combination and modification of the two others, and it is largely used for the internal soldering of bottoms of large drums, milk churns, etc., where great local heat is required.
Fig. 4.—Home-made Soldering Bit
Fig. 5.—Bit for Internal Soldering, etc.
Fig. 6.—Hatchet Soldering Bit
As to the size of bit required, for ordinary small work the straight type should not be less than 8 oz. or 10 oz. (weight of the actual copper).
Two bits are very useful in doing a large job, as the work can then be arranged to progress continuously, one bit heating while the other is in use.
A bit suitable for quite light work can be easily made by drilling and tapping a piece of copper, say 1⁄2 in. by 1⁄2 in. by 11⁄2 in. long, either in the end or in the side, for a 3⁄16-in. steel rod 12 in. long, a handle being then fitted at the other end.
In the “Tinol” telescopic soldering bit for amateurs’ use, the handle is in three parts: (a) the actual wooden handle bushed with metal, and provided with a set-screw shaped like a screw eye, and therefore easily turned; (b) a steel tube which telescopes into the first part, and which is also provided with a set-screw; and (c) a short rod, having at one end a hatchet-shaped copper bit. The extreme length of the tool is 12 in., and the length, when the parts are telescoped together, is about 5 in.
The “Fluxite” bit is larger and heavier. It has a hollow cast-iron handle, perforated to dissipate the heat, threaded internally at one end to receive the screwed end of the iron stem, only 5 in. or so in length, which at the other end screws into an adapter or holder which, in turn, receives the screwed end of the copper bolt, itself about 4 in. long. The bit is taken to pieces in a few moments, and is quite a workmanlike tool.
Fig. 7.—Spirit-heated Bit
Spirit-Heated Soldering Bits.