The solder will soon stick to the copper surfaces and then the iron is ready for use.
Another way to tin the iron that is in common use is to rub the point of a hot iron on a piece of sal-ammoniac, or dip the hot iron in reduced muriatic acid, then rub the stick of solder on the iron. The use of muriatic acid in tinning the iron is not recommended. In the first place, it is not always possible to carry it, and in the second place it eats holes in the surface of iron, which makes it necessary to file and smooth the surfaces again. The constant use of muriatic acid on the copper soon wears it away and makes it unfit for use. Rosin is easily carried and applied and is by far the best to use in regular work.
Points to Remember in the Care of the Soldering Iron.—
- First, proper tinning is absolutely necessary for rapid and good work.
- Second, do not allow the iron to heat red hot.
- Third, keep the point of the iron properly shaped.
- Fourth, use the same flux in tinning as is to be used in soldering.
- Fifth, when filing iron, file as little as possible.
- Sixth, keep in use two irons of the same size.
FLUX
A flux is used to clean the surfaces of joints and seams to be soldered, also to keep them from oxidizing and to help the metals to fuse.
The following list gives the names of various fluxes in common use, how they are applied, and on what material they are most commonly used:
| Flux | How applied | Used on |
|---|---|---|
| Rosin | Sprinkled on | Lead, tin, and brass |
| Tallow | Melted | Lead and brass |
| Muriatic acid (reduced) | With swab | Copper, galvanized iron |
| and brass | ||
| Muriatic acid (raw) | With swab | Dirty galvanized iron |
Rosin.—Rosin is purchased by the pound and comes in chunks. It is very brittle and powders easily. Plumbers generally take a piece of 11⁄4 N. P. brass tubing, solder a trap screw in one end and a cone-shaped piece of copper on the other. The point of the cone is left open. Rosin is put into this tube and is easily sprinkled on work when needed.
Tallow.—A plumber's tallow candle answers the purpose for tallow flux. Some plumbers carry a can for the tallow, making it cleaner to handle.