To Weld Cast-Iron.—Take of good clear white sand, three parts; refined solton, one part; fosterine, one part; rock-salt, one part; mix all together. Take 2 pieces of cast-iron, heat them in a moderate charcoal-fire, occasionally taking them out while heating, and dipping them into the composition, until they are of a proper heat to weld; then at once lay them on the anvil, and gently hammer them together, and, if done carefully by one who understands welding iron, you will have them nicely welded together. One man prefers heating the metal, then cooling it in the water of common beans, and heat it again for welding.
To recut old Files and Rasps.—Dissolve 4 oz. of saleratus in 1 quart of water, and boil the files in it for half an hour; then remove, wash and dry them. Now have ready, in a glass or stoneware vessel, 1 quart of rain water, into which you have slowly added 4 oz. of best sulphuric acid, and keep the proportions for any amount used. Immerse the files in this preparation for from six to twelve hours, according to fineness or coarseness of the files; then remove, wash them clean, dry quickly, and put a little sweet oil on them to cover the surface. If the files are coarse, they will need to remain in about twelve hours, but for fine files six to eight hours is sufficient. This plan is applicable to blacksmiths', gunsmiths', tinners', coppersmiths' and machinists' files. Copper and tin workers will only require a short time to take the articles out of their files, as the soft metals with which they become filled are soon dissolved. Blacksmiths' and saw-mill files require full time. Files may be recut three times by this process. The liquid may be used at different times if required. Keep away from children, as it is poisonous.
Twist, Browning for Gun-Barrels.—Take spirits of nitre ¾ oz.; tincture of steel, ¾ oz.: (if the tincture of steel cannot be obtained, the unmedicated tincture of iron may be used, but it is not so good) black brimstone, ¼ oz.; blue vitriol, ½ oz.; corrosive sublimate, ¼ oz.; nitric acid, 1 dr. or 60 drops; copperas, ¼ oz.; mix with 1½ pts. of rain water, keep corked, also, as the other, and the process of applying is also the same.
Gun Metal.—1. Melt together 112 lbs. of Bristol brass, 14 lbs. of spelter, and 7 lbs. of block tin.—2. Melt together 9 parts of copper and 1 part of tin; the above compounds are those used in the manufacture of small and great brass guns, swivels, etc.
Chinese Method of Mending Holes in Iron.—The Chinese mend holes in cast-iron vessels as follows: They melt a small quantity of iron in a crucible the size of a thimble, and pour the molten metal on a piece of felt covered with wood-ashes. This is pressed inside the vessel against the hole, and as it exudes on the other side it is struck by a small roll of felt covered with ashes. The new iron then adheres to the old.
Common Pewter.—Melt in a crucible 7 lbs. of tin, and when fused throw in 1 lb. of lead, 6 oz. of copper and 2 oz. of zinc. This combination of metal will form an alloy of great durability and tenacity; also of considerable luster.
Best Pewter.—The best sort of pewter consists of 100 parts of tin, and 17 of regulus of antimony.
Hard Pewter.—Melt together 12 lbs. of tin, 1 lb. of regulus of antimony, and 4 oz. of copper.
To Mend Broken Saws.—Pure silver, 19 parts: pure copper, 1 part: pure brass, 2 parts; all are to be filed into powder and intimately mixed. Place the saw level upon the anvil, the broken edges in close contact, and hold them so: now put a small line of the mixture along the seam, covering it with a large bulk of powdered charcoal; now with a spirit lamp and a jeweler's blow-pipe, hold the coal-dust in place, and blow sufficient to melt the solder mixture: then with a hammer set the joint smooth, if not already so, and file away any superfluous solder; and you will be surprised at its strength.
Solder, to Adhere to Brass or Copper.—Prepare a soldering solution in this way: Pour a small quantity of muriatic acid on some zinc filings, so as to completely cover the zinc. Let it stand about an hour, and then pour off the acid, to which add twice its amount of water. By first wetting the brass or copper with this preparation, the solder will readily adhere.