CHAPTER XXXIV.
MISCELLANEOUS RECIPES.
Soft Soldering.—Soft solder, so called, is a composition made by melting together two parts tin and one part lead. If the gunsmith ever has occasion to use it, he will need a soldering fluid, which is made by dropping clippings of zinc into muriatic acid until ebullition has ceased, then adding to the acid its equal in bulk of pure water, although some mechanics do not consider the addition of water as necessary.
Clean thoroughly the parts to be soldered together, then wet them with the soldering fluid. Next place in the joint a thin bit of the soft solder, and expose to heat, the heating agent to be clear of oil. The pieces should be held, pressed between the blades of large tweezers, so that when the solder melts the two parts will come directly together. So soon as the solder melts, the work must be taken from the fire, as the soldering will be complete. A little longer exposure would burn the solder and spoil the work.
Good Soft Solder.—Good soft solder is composed of equal parts of pure tin and good soft lead. The lead from old tea-chests is excellent. Plumbers’ solder is often made of lead three parts and tin one part.
Soldering Fluid.—A soldering fluid for jewelers’ use is made by adding to alcohol all the chloride of zinc it will dissolve.
Brazing.—This consists in uniting iron and other hard-melting metals with a brass solder. Put the parts together as for soft soldering, lay the brass between the pieces or along the upper edge of the joint, if it can be held vertically, and add a goodly supply of pulverized borax to act as a flux. Heat over a charcoal fire till the brass melts and runs down into the joint, then take from the fire and cool. Before beginning the operation of brazing the parts to be put together must be made entirely clean, and then freshly filed to brightness.
To Braze Lugs on Gun Barrels.—When not practicable to fasten the lugs by means of pins or rivets, hold them in place with binding wire. Take a piece of iron, say ¼ inch thick and 2 inches or more in width, and make in it a slot some larger than the lug to be brazed. Lay the barrel on the iron sideways, and pack up the lug so as to lie level, if necessary, also taking care that it is on straight. Pure copper is excellent for all kinds of brazing, when the color of the copper is not objectionable.
Hard Soldering.—See “To Solder Brass,” in [Chapter XII], which about covers the whole thing, varying only in the composition of the solder for different metals. The brass solder there described acts equally well for soldering copper, but for silver a solder is made composed of two parts silver and one part brass.