Shellac Cement for Rubber.—Soak in a glass fruit jar 1 ounce of gum shellac in 10 ounces of strong aqua ammonia. Let stand 3 or 4 weeks, or until the shellac is dis solved. Used to cement rubber to wood or metal. This cement softens the rubber, and after the ammonia evaporates, the union will be found to be both air - tight and water tight.
Rosin Cement.—Melt together with gentle heat 8 ounces of rosin and 4 ounces of sulphur, and pour into molds for future use. When wanted, grind to powder 2 ounces of this mixture, and add ounce of iron filings, fine sand, or brick dust. Fill the opening in the handle of a knife, fork, or other implement with this mixture, heat the stock, and force it into the handle while hot.
Or mix 4 ounces of rosin, 1 ounce of beeswax, and 1 ounce of fine brick dust. This cement is used by cutlers. Fill the openings in knife handles with this mixture, heat the stock of the knife, and force it into the handle. When cold it will be firmly set.
Or mix pound of rosin and 1 pound of brick dust. Melt with gen tle heat. Used by plumbers. Apply while hot to joints in lead pipe.
Or melt together 5 ounces of black rosin and 1 ounce of yellow wax, and stir in gradually 1 ounce of red ocher or Venetian red in fine, dry powder. Melt and apply warm. Used by in strument makers for cementing glass to metal.
Or melt 15 ounces of rosin and 1 ounce of wax, and add 4 ounces of whiting previously heated red hot and mixed while warm. Used by glass grinders to hold glass, stones, etc., while being polished or cut.
Rosin and Wax Cement or Bottle Wax. — Mix 4 ounces of rosin, 4 ounces of sealing wax, and 2 ounces of beeswax; melt together with gen tle heat. When the mixture boils, stir it with a candle.
Or melt equal quantities of bees wax and rosin. Used to seal bottles. First insert a cork into the bottle, and then dip the cork and neck of the bottle in the melted wax.
Grafting Wax.—Melt together with gentle heat 1 pound of rosin, 3 ounces of tallow, and 5 ounces of beeswax. Stir continually while melt ing. Pour the mixture into cold wa ter and let stand until cool. Then remove from the water and knead thoroughly to a homogeneous mass. This wax will last for years. It is not soft enough to run in hot weather not hard enough to crack in winter.
Amber or Varnish Cement.—Dis solve 2 ounces of amber in 3 ounces of sulphide of carbon. Apply with a brush and hold the surfaces firmly together until dry. This cement sets almost immediately.
White-of-egg Cement.—For crock ery, white of egg mixed with pre pared lime, or mixed with the same material (ground to powder) as the article to be mended, makes a firm and durable cement. Apply quickly
to the edges and hold firmly to gether until the mixture sets. Do not mix more than is required, as it hardens very quickly and cannot be melted.
Or use for this purpose the white of an egg with plaster of Paris or prepared chalk or finely powdered oyster shells.
Or pound the lime or other solid to a fine powder and sift it through cheese cloth. Apply white of egg freely to the broken surfaces. Dust on the powder and hold the edges together firmly until united.
For glassware, grind a piece of flint glass to the finest powder, mix with white of egg, and apply.
To Mend Ironware.—Make a thin paste of finely sifted lime with the white of an egg and thicken with iron filings. Apply to the broken edges and hold them firmly together until the cement sets.
Casein Cement.—Grate 4 ounces of old cheese in pint of milk. Let stand all day, stirring frequently. Stir in 4 ounces of unslaked lime reduced to fine powder and sifted through cheese cloth. Add the whites of 6 eggs and mix all thoroughly with an egg beater. This was long regarded as a trade secret in Eng land for mending earthenware.
Or add pint of vinegar to pint of milk. Separate the curd from the whey and mix the whey with the whites of 4 or 5 eggs by means of an egg beater. Stir in powdered and sifted quicklime to the consist ency of a thick paste. This cement is said to be fireproof and water proof.
Or dissolve casein in a cold satu rated solution of borax. This is a substitute for gum arabic and dex trin for envelopes, labels, and the like.
Or, to mend earthenware, place the pieces together and tie them firmly as possible by means of a string. If one piece of a set is broken, two other pieces of the same set may be placed one on each side of the broken article to assist in keeping the pieces together, but care must be taken to first wind string thickly around the broken plate or dish so as to separate it slightly from the others and permit liquid to flow around it. Then put it in a boiler or kettle, cover with cold sweet skimmed milk, and let stand for an hour or more to get an even temperature. Bring to a boil with gentle heat and let boil ten or fif teen minutes. Remove from the fire and let stand over night. Wash in warm water and let stand two or three days without using. The dish will be found to be as strong as new.