—Bits heated by benzoline or spirit may be made with a small barrel-shaped reservoir which also forms the handle. One end of the reservoir is fitted with a filling cap, and from the opposite end protrudes the tube carrying the burner. To the tube end of the reservoir an iron clip is attached, and this secures an iron bar which stands out over the burner head. At the end of this bar the copper bit is attached and held either vertically or horizontally in the flame. Tool merchants’ catalogues show a variety of such implements. [Fig. 7] illustrates one of the most elaborate of them all, the weight complete being 21⁄4 lb. It has a polished brass container A, of 1⁄5 pint capacity—sufficient for 45 to 60 minutes, whence the benzoline flows to the burner B, the flame from which heats the copper bit C. This bit may be of any of the regular shapes, and weighs about 1⁄2 lb. The position shown is that for heating the bit preparatory to soldering. The tray D catches any drips that might occur at starting, E is the stand, F the filler cap, G is the regulating handle, and H is the clamp that holds the bit in place.
Fig. 8.—Bit attached to Blow-lamp
A writer in Popular Mechanics has stated that the ordinary blow-lamp, with the burner end equipped with a copper bolt (see [Fig. 8]), makes an excellent soldering device. The point can be easily kept at the proper heat, and there will be no want for hot coppers. The end of the burner is threaded on the outside, and a hole is drilled in the copper point and threaded to match. Small holes are drilled in the copper in the same manner as in the burner, to make vents for the flame.
Fig. 9.—Gas-heated Bit
Gas-heated Bits.
—These are largely used in factories, and are cleanly, expeditious, safe, and convenient. The type shown by [Fig. 9] is very handy, and the illustration and description are due to F. X. Sommers, Jun., in the American Machinist. A mixture of air and gas enters the pipe at about 10 lb. pressure, or enough to give a hot, blue flame. The part A is of cast-iron, which, on experiment, has been found to last longer without corroding than steel, although copper would be better. The soldering bolt B was made of steel because it kept the correct shape point much longer than cast-iron or copper, although the latter metal is better for transmitting the heat. The point should be tinned before using. This form of soldering head is being used on automatic can-soldering machines, and does the work effectively. It also saves gas. It will heat to the correct temperature in about 11⁄2 minutes.
Fig. 10.—Gas-heated Bit complete