Or use clay instead of tallow.
Or heat the iron to redness and cov er it with hellebore.
Or quench it in the water in which common beans have been soaked.
To Temper Cast Iron.—New cast iron stoves, kettles, flatirons, and oth er articles should be gradually tem pered by heating for a number of hours on a slow fire. If heated quick ly and violently when new, they may crack, and at best they will not after wards retain the heat equally well.
To Weld Iron.—To unite two pieces of welding iron, it is only necessary to raise them both to a white heat and hammer them together to make them one. The softer the iron the easier it can be welded. Hence it as sists in welding to draw the temper of cast iron or steel before welding.
Or, to weld cast iron, mix 3 pounds of clean white sand, 1 pound of rock salt, 1 pound of fosterine, and 1 pound of pure solton. Heat the iron slowly in a charcoal fire, and while heating dip the parts to be welded in this mixture from time to time.
Or melt together 1 pound of borax and 2 ounces of red oxide of iron. Let the mixture cool, pulverize it, and keep it for use in the form of dry powder. Sprinkle the parts to be welded with this powder.
To weld a small piece of iron on to a large one, raise the larger piece to a white heat, heat the smaller piece to a proper welding heat, and sprinkle the parts with this mixture. The re sult will be a good joint with less heat than would otherwise be required.
Or mix equal parts of cast-iron fil ings and calcined borax, and melt them together in a crucible. Pulver ize the resulting mixture, which will form a black powder. Cover the parts to be welded with this sub stance, heat them, and weld them with light blows on an anvil.
To Solder Steel and Iron.— When welding is not convenient, steel or iron surfaces may be united by means of solder. To solder steel or iron, use brass filings, or mix 3 parts of brass with 1 part of zinc.
To make this solder, first melt the brass, add the zinc in strips, and cov er tightly until the metals have united. Lay twigs across a vessel of water and pour the metal over these into the water to make it form long strips, or pour it into a suitable mold. Dip the
surfaces to be soldered in alcohol or acid, scour and scrape them perfectly clean, and, if possible, place them in a vise, or otherwise secure them strong ly together. Weight the parts and cover with borax. Apply the solder, and melt it in the flame of a coke fire over a hearth with bellows.
Or mix equal parts of soft brass powder and borax. Apply to the parts and melt.
To Solder Castings.—Clean with al cohol or acid, scrape and scour, and apply soldering liquor to the parts. Cover with sal ammoniac, and heat until the sal ammoniac gives off fumes. Then dip the parts into pure tin melt ed. Afterwards apply any ordinary hard solder, as brass, 2 parts; zinc, 1 part; or copper, 2 parts; tin, 1 part, and the like.
To Solder Steel Joints. — For fine steel work, melt together under a layer of powdered charcoal 18 parts of silver, 1 part of copper, and 2 parts of brass. This melts at a low heat, has a whiter color, and is therefore nearer the color of the steel.
Or cleanse the parts by scrubbing, filing, or rubbing with alcohol or acid, and tie them together with brass wire. Repeat in such a way that when melted the brass will run into the seam. Apply to the joints and also to the wire a paste of borax and water, and hold in a bright coke fire until the brass melts and runs into the joint. This will cause a blue flame to rise, which will show that the heat is sufficient.
Or mix 4 parts of dry plaster of Paris and 1 part of iron filings with water to the consistency of thick cream, and apply quickly before it sets.
To Mend Ironware.—To mend holes in ironware, melt a little iron or ex pansion metal in a crucible and pour it on to a pad of asbestos or thick felt protected by ashes, slightly hol lowed in the middle to receive it. Press this against the hole so that the iron will come through on the other side, and meet it with another pad of asbestos, holding it thus until it sets. The hole will thus be permanently plugged.