Metal and Glass Secrets.

Hardening Composition for Steel.

Spermaceti oil95  quarts.
Melted tallow20  pounds.
Neat’s foot oil4 1/2 quarts.
Pitch1  pound.
Rosin3  pounds.

Melt the rosin and pitch together, add the other ingredients, and heat all in an iron vessel until all moisture is driven out, and the heated mass ignites from a burning chip of wood held over it; the flame is at once extinguished by a close-fitting lid.

In using the method for saw blades, they are first heated in a suitable furnace and then placed vertically, teeth upward, in troughs filled with the mixture. After sufficient cooling they are taken out and wiped with a piece of leather so that only a slight film of fat remains. They are then placed flat over a coal fire until the coating of fat ignites, which may burn as freely as required for great hardness. Screws, or other articles which require a less degree of hardness, are dipped into the hot mixture and brought to a white heat.

Composition to Toughen Steel.

Resin2 pounds.
Tallow2 pounds.
Black pitch1 pound.

Melt together and dip the steel in the mixture when hot.

To Soften Iron or Steel.

Anoint the article all over with tallow, temper it in a gentle charcoal fire, and let it cool itself; or take a little clay, cover your iron with it, and temper in a charcoal fire.

Restoring Burnt Steel.

It is not generally known that burnt steel may be almost instantaneously restored by plunging it while hot in cold water and hammering it with light strokes on the anvil, turning it so as to hammer all over it, again dipping in the cold water, and repeating the hammering process as before. Try again if you do not succeed the first time.

Welding Cast-Steel.

Rock saltpeter 1/4 pound.
Oil vitriol 1/4 pound.
Water1  gallon.

Dissolve the saltpeter in the vitriol and add it to the water. After scarfing the steel get it hot; and quench in the preparation. Then weld the same as a piece of iron, hammering it very quickly with light blows. It answers the purpose much better than borax. Cork it in a bottle and it will keep for years.

Another:

Borax15 parts.
Sal-ammoniac2 parts.
Cyanide of potassium2 parts.

Dissolve all in water, and evaporate the water at a low temperature.

To Drill Hardened Steel.

Cover your steel with melted beeswax, and when cold make a hole in the wax with a fine-pointed needle or other article the size of the hole you require; put a drop of strong nitric acid upon it, and after an hour rinse off and apply again. It will gradually eat through.

To Drill Holes in Cast-Iron.

By means of carbolic acid a hole  1/4 of an inch in diameter has been drilled through  1/2 inch thickness of cast-iron with a carpenter’s brace.

To Solder Ferrules for Tool Handles.

Take your ferrule, lap round the “joining” a small piece of brass wire, then wet the ferrule, scatter on the joining ground borax, put it on the end of a wire, and hold it in the fire till the brass fuses. It will fill up the joining and form a perfect solder. It may afterward be turned in the lathe.

Soldering Without a Soldering Iron.

Cut a piece of a tin-foil the size of the surface to be soldered, then pass over the surface a solution of sal-ammoniac, place the tin-foil between the pieces, and heat over a lamp or fire until the foil melts. Instead of the solution of sal-ammoniac equal parts of water and hydrochloric acid saturated with zinc can be used just as well.

To Clean Gun-barrels from Lead.

Pour in a little mercury, agitate it over the interior surface of the barrel, and pour it out again. The mercury will amalgamate the lead and remove it.

To Resharpen Old Files.

Saleratus4 ounces.
Water1 quart.

Dissolve the saleratus in the water. Boil the old files or rasps in this solution for half an hour. Then take out, wash, and dry them. Next stand them in a jar, filling it up with rain water and sulphuric acid in the proportion of water, 1 quart; sulphuric acid, 4 ounces. Coarse files should remain in the bath twelve hours and fine ones two or three hours less. Take them out, wash them clean, dry quickly and thoroughly, and rub them with sweet oil to prevent rusting.

Another method, though not so effectual, is to pour a few drops of benzole upon the file and brush thoroughly with a scratch brush.

Mending Tinware by Candle Heat.

This is such a simple and cheap way of mending tinware that a person with just a bit of ingenuity can do his own work in this line. Take a vial about two-thirds full of muriatic acid and put into it little bits of sheet zinc as long as the acid will dissolve them. Then put in a crumb of sal-ammoniac and fill up with water and it is ready for use. Wet the cork in the vial and with it wet the edges of the place to be mended. Then put a piece of sheet zinc over the hole and hold a lighted candle or spirit lamp under the place, which melts the solder on the tin and causes the zinc to adhere without further trouble. Do not forget to wet the zinc also with the solution.

A Good Way to Sharpen Razors.

Put the razor blade for half an hour in water to which has been added one-twentieth of its weight of muriatic or sulphuric acid, and after a few hours “set” it on a hone. The acid acts as a whetstone by corroding the whole surface uniformly.

Razor-Strop Paste.

Moisten flour of emery with tallow or sweet oil.

Cutting Ovals and Different Shapes on Glass.

Scratch the glass around the shape you desire with the corner of a file or graver; then having bent a piece of wire the same shape heat it red-hot and lay it upon the scratch, and sink the glass into cold water just deep enough for the water to come almost on a level with its upper surface. It rarely fails to break perfectly true.

Etching on Glass.

Barium sulphate3 ounces.
Ammonia fluoride1 ounce.

Acid sulphuric, a sufficient quantity to decompose the ammonia fluoride and making the mixture of a semi-fluid consistency. It must be prepared in a leaden vessel. It can be used with a common pen, but must be kept in bottles coated inside with paraffine, beeswax, or gutta-percha, with rubber stoppers.

To Drill and Ornament Glass.

Any hard steel tool will cut glass with great facility when kept freely wet with camphor dissolved in turpentine. A drill-bow may be used, or even the hand alone. A hole bored may be readily enlarged by a round file. The ragged edges of glass vessels may also be thus easily smoothed by a flat file. Flat window glass can readily be sawed by a watch-spring saw by aid of this solution. In short, the most brittle glass can be wrought almost as easily as brass by the use of cutting-tools kept constantly moist with camphorized oil of turpentine.