VOLATILE-OIL VARNISHES These are solutions of various res ins, principally gum copal, Canada balsam, resin, and others in oil of turpentine; are more durable and less brittle than spirit varnishes, but re quire more time in drying.
Like fixed-oil varnishes, they im prove with age, whereas spirit var nishes deteriorate in quality. The res ins may usually be dissolved in oil of turpentine without being previously melted. Seven pounds of oil of tur pentine will usually dissolve about 5 pounds of resin.
To make ordinary turpentine var nish, dissolve with gentle heat pound of poivdered white resin in 1 pint of turpentine. Or other proportions rec ommended range from 3 to 5 pounds of resin in 1 gallon of turpentine.
Canada Balsam Varnish with Tur pentine. — Mix equal parts of pure Canada balsam and pale oil of turpen tine. Dissolve with gentle heat and shake occasionally. Let stand two or three days, strain, and filter. This
varnish improves with age.
Copal Varnish with Turpentine.— Dissolve 3 ounces of copal in 1 pound of oil of turpentine.
Ether Varnishes.—These are a solu tion of various resins in ether. They are very little used.
To make an ethereal copal varnish, dissolve 5 ounces of copal and 2 ounces of ether. This is suitable for repair ing jewelry, as, for example, broken enamel, for the setting of gems, and the like. It may be applied to wood by first rubbing the wood with a cloth moistened in oil of turpentine, wiping with a linen cloth, and then applying the varnish. This prevents the ether from evaporating too rapidly.
To make ethereal amber varnish, dissolve 4 grains of amber in 1 ounce of chloroform. Use this for varnish ing photographs, maps, etc.