H. M. CHADWICK

The articles necessary for doing ordinary soldering are the flux, the scraper (an old knife will answer very well for the latter) the iron and the heater.

The Flux. This is a fluid made from acid that must be used to coat all surfaces to be soldered. Good soldering fluids maybe purchased at the hardware stores, but as satisfactory a one as any can be made by pouring a tablespoonful of hydrochloric acid over a piece of zinc the size of a half dollar. Let the acid act until the zinc is taken up. Strain the resulting fluid, which is zinc chloride, and put it into a bottle with a glass stopper. It will keep a longtime. Avoid bringing the fingers in contact with the flux, as it makes the skin sore.

The Iron. The soldering iron is realy not an iron at all, but a piece of copper fitted with a handle. For ordinary work, use an iron about 3" long 7/8" to I" in diameter. Smaller ones are good for very small work but will not hold the heat long enough to do a good job on a seam several inches in length.

Make a cleaning pad from a pieces of old cloth folded into several thicknesses and tacked to a board.

To prepare the iron for use, file the end for about an inch from the point bright and smooth and heat it very hot, but do not let it get red.

Wipe the hot iron clean on the cloth, dip the bright end into the flux and apply it to the end of a stick of solder. If the iron is hot enough the solder will melt and stick to the iron. Let a few drops fall to the cloth and rub the iron around in the molten Bolder. This will tin the implement thoroughly.

The Bunsen burner is a good thing over which to heat an iron, provided there is gas in the house, but a coal fire does very well, though it is not so clean.

Suppose, now, one wishes to mend a hole in a tin pan. Scrape a surface around the hole equal in area to that of a dime, using an old knife or, perhaps, a piece of emery cloth, being sure to remove all grease and dirt. Do not even rub the place with the fingers after getting it clean. Apply a little flux with a brush or a piece of clean wood. Cut a piece of solder from the stick the size of a small pea and place it over the hole. Next, rest the iron, well heated and tinned, on the cold solder, and the latter will melt at once and spread over the cleaned surface.

To prevent the solder from running through the hole, rest the pan on a flat piece of wood, thus bridging the opening, Another and better way is to smear a small quantity of plaster of Paris on the under side of the pan.

Agate ware can be mended in this manner as well as plain iron and tin. Chip off the agate covering with a few careful blows from a hammer or the blunt end of a heavy file. Scrape the metal clean and solder as directed.

To solder a seam, such as the lapping edges of a tin box, proceed as already stated, but tilt the box slightly so that the solder will tend to run downwards and fill the seam. The molten solder will follow the iron as it is drawn along the crack, provided the iron is hot enough and well tinned.

Never cool soldered articles by dipping them into water. Solder sets better if allowed to cool in the air. If the molten solder collects in little balls and refuses to spread over the cleaned surface, there is dirt or grease present. If the solder melts but does not run and collects in pasty bunches, the iron is not hot enough. If the melted solder refuses to follow a good hot iron, then the iron is dirty and had better be filed and retinned, or at least rubbed on the cloth.

The novice will undoubtedly waste much solder, in spite of careful effort,but this fact should not discourage him, as a little practice will teach him to avoid this error. The next article will treat of the blowpipe and Bunsen burner and their uses in connection with soldering.