FIXED-OIL VARNISHES Solutions of resins in boiled lin seed oil have the same durable qual ity as oil paint, with the addition of a high luster. As in paint, the linseed oil absorbs oxygen from the air, and is converted into a tough, elastic waterproof substance.
To prepare fixed-oil varnishes, melt the resins anime, amber, copal, etc.; heat the boiled linseed oil to a high temperature, and pour It into the melted resin in a thin stream, stir ring constantly. To test the proper amount of linseed oil to be added to the resin, take out a drop of the fluid now and then and let it cool on a glass plate. When the proportion: of oil and resins are correct, the drop will be limpid like wax. If the drop becomes hard and brittle, more oil is required. When mixed, remove from the fire and allow the mixture to cool. Then dilute to the proper consistency by pouring in turpentine in a thin stream and stirring constantly.
But first boil the mixture of lin seed oil and resin before adding the turpentine.
The best quality of linseed oil should be employed for a varnish.
The proper proportions for an or dinary oil varnish are about 10 parts by weight of resin, 5 to 95 parts of boiled linseed oil, and 15 to 95 parts of oil of turpentine. Varnishes of this character usually improve with age. The following are formulas for fixed-oil varnishes: Amber Varnish.—Eight ounces of amber, 5 ounces of boiled linseed oil, and pint of oil of turpentine. This varnish is very durable, but a slow dryer.
Or, for larger quantities, 6 pounds of amber, 9 gallons of hot linseed oil, and 4 gallons of oil of turpentine. Melt the amber, add the linseed oil hot, and boil until stringy. Cool and add the turpentine.
Or amber, 16 ounces; boiled linseed oil, 10 ounces; Venetian turpentine or gum lac, 9 ounces; oil of turpentine, 15 or 16 ounces.
Or melt 4 pounds of resin and 4 pound of beeswax. Add 1 gallon of boiled oil at a high temperature. Mix and boil until stringy. Cool and add 9 quarts of turpentine.
Or melt 1 pounds of rosin, add 1 pound of Venetian turpentine, then stir in 1 gallon of boiled linseed oil at high temperature. Boil until
stringy; cool and thin with 1 quart of turpentine. The above are ordinary oil varnishes suitable for common work.
Copal Varnish.—Fuse 2 ounces of African and add 4 ounces of best boiled linseed oil at a high tem perature. Boil until stringy, cool, and add 8 ounces of oil of turpentine. This is a transparent body varnish, hard, clear, and durable.
Or melt 4 ounces of copal, and add at a high temperature 2 ounces of boiled linseed oil. Stir and thin with 3! ounces of turpentine. To make a white copal varnish, color the above with the finest white lead.
Anime Varnishes.—Melt 4 pounds of gum anime and add at a high tem perature II gallons of boiled linseed oil. Boil until stringy. Stir in 2 ounces of camphor and 2 ounces of litharge, cool, and thin with 2! gal lons of oil of turpentine. This is a good carriage or furniture varnish.
Or, for a finer grade of work, melt 4 pounds of gum anime; add at a high temperature II gallons of clari fied linseed oil, 2 ounces of litharge, 2 ounces of dry acetate of lead, and 21 gallons of turpentine.
Lac Varnishes.—Dissolve 1 pound of shellac, and add at a high temper ature 2 quarts of boiled linseed oil. Stir in pound of red lead, pound of litharge, and 2 ounces of umber. Boil until stringy. This dries rapid ly, and has a high gloss.
Waterproof Varnish.—Dissolve 1 pound of flowers of sulphur in 1 gal lon of boiled linseed oil. Boil and stir until they form a perfect emul sion. This is a good waterproof var nish for woven goods.
Or cut India rubber in small pieces, put them in a glass bottle with benzine, and let stand four or five days, shaking frequently. Strain through cotton to remove the ben zine, and thin with boiled linseed oil or turpentine.
Flexible or Balloon Varnish.—Cut 1 pound of India rubber into fine pieces and boil in 1 pound of linseed oil until dissolved. Cool, and add pound of turpentine. Simmer with gentle heat and strain through cheese cloth.