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1950-51 Theatre Catalog, 9th Edition, Page 420 (398)

1950-51 Theatre Catalog, 9th Edition
1950-51 Theatre Catalog
1950-51 Theatre Catalog, 9th Edition, Page 420
Page 420

1950-51 Theatre Catalog, 9th Edition, Page 420

THE EFFECT OF TIME ON VARNlSH. At the left is a picture (magnification: :5) of a good clear varnish film after 48 weeks' exposure in Florida. The panel IthI no checking or cracking, has good gloss, and would be rated tions. Here the surface is uniformly checked and cracked and the coat

in Iatilfactory condition except that the panel shows some peeling from

the manufacture of flat wall paints and under coats.

Color varnishes, in contrast to enamels, are usually interior varnishes to which transparent or translucent coloring matter has been added. When the coloring matter is opaque, the varnishes are properly designated as enamels.

Rubbing Varnish is a hard-drying varnish, to be rubbed with a soft abrasive and water or oil to a uniform level surface. Varnishes of this class are usually of the short-oil type.

Baking varnish is intended for use on either wood or metal objects to be dried by heat, usually in a suitable oven. A baking varnish, as a rule, contains more oil and less dryer and is more elastic than an air-drying varnish for similar use, as the baking process will dry a varnish containing considerable oil in a reasonable time. Tests have proved that varnish, when properly baked, is more resistant and durable than the same varnish when air-dried, due principally to more thorough, uniform polymerization.

Mixing varnishes are those intended to be added to paints for the purpose of imparting luster or hardness or both. The chief requisites for a mixing varnish is that it shall mix without separation, precipitation, or reaction with any constituent of the paint.

Paste wood fillers, supplied for filling the grain of hard woods so as to produce a level, non-absorbent surface for varnishing, consist usually of finely powdered transparent or translucent mineral substances ground in a special type of varnish. They are applied by brushing and, after setting but before hardening, the surplus is wiped from the surface of the wood. They may be colorless, or colored so as to utilize the grain patterns for decorative effect.

Liquid wood fillers are varnishes of low viscosity, usually containing very finely divided transparent or translucent solid matter, for use a first coating on porous, fine-grain woods, such as poplar and white pine, and to afford a non-absorbent surface for the succeeding coats of varnish. They are frequently colored so as to stain and fill in one operation.

Varnish removers are blends of organic liquids designed for the rapid softening of old varnish coatings, so that they may be removed easily by scraping.

Uses of Varnishes

In the selection of a varnish, the reputation and experience of the manufacturer is of first importance. The varnish user will be safer in selecting a manufacturer than in selecting a varnish.

The only safe test for a varnish, no matter what its intended use, is actual service, and, where time for such a test is available, it should not be neglected.

Quality, of course, is another prime consideration governing the selection of varnishes. That point being conceded, the situation, purpose, color, kind of surface and the style of finish desired should also be brought to bear on the choice.

The finishing coat is the final coat of varnish applied to a surface for decorative effects. It may be the first and only coat on cheap articles, where nothing beyond a superficial finish is required; it may be the third, fourth, or fifth coat on interior wood work; and it may even be the fifth or sixth on fine coaches, and so forth. As a general rule, no less than three coats will produce a satisfactory finish.

Interior varnishes are designed for use on interior surfaces of dwellings and other inhabited structures. As the effects required are diverse, the varieties are numerous, including varnishes intended to produce, without further treatment, on all kinds of surfaces, from a lusterless, wax-like coating to a highly lustrous coating. In still another class are the rubbing and polishing varnishes.

The qualities most desirable in interior varnishes are fair body, moderately rapid drying, fairly light color, fiuidity, moderate hardness, indifference to occasional moisture, permanence of luster, and durability. As interior varnishes are not subjected to the severe conditions of outside exposure, they may, without detriment, to be inferior to exterior varnishes in their qualities of resistance.

the edges. One lees virtually only the texture of the wood! At the right in a picture (also x6) of a poorer quality varnish under the some condi has become darkened as almost to obscure the grain. (S-W photographs.)

Floor varnishes-The use of fioor varnish is indicated by its name. Shellac varnish is much used for this purpose, especially over light colored wood; but the newer quick-drying fioor varnishes are more durable. Floor wax is generally applied periodically over shellac.

Since the largest application to floors is to those already in use, convenience requires that a good fioor varnish be highly elastic, dry moderately hard over night, and be ready for use within 48 hours, be tough and resistant to shock or abrasion, and be unaffected by moderate contact with moisture. It possesses, in fact, the general qualities of a spar varnish, except that it dries more quickly to a harder film.

In the proper care of varnished fioors, the most important precaution is that a fresh coat of varnish be applied before the old coating has worn through at any place. If this precaution is neglected, it will be practically impossible to produce an unbroken surface without removing the entire coating.

Linoleum Varnishes are special, highly fiexible and elastic varnishes used in both clear and pigmented forms as finishing coats on linoleum floors, and the like. Good fioor varnish makes an excellent material for renewing these.

Exterior Varnishes are designed to resist exposure of the exteriors of buildings. They must be durable, elastic, resist abrasion, moisture, the atmOSphere, and the light and heat of the sun.

Insulating Varnish is one designed to protect electrical conductors and the like, and at the same time, to prevent leakage of current, short-circuiting, and so forth. These are special products in which the prime desideratum is permanent non-conductivity. Shellac and some of the synthetic resins have high dielectric strength.

All-Purpose Varnish is a general utility product designed to meet all the requirements of non-professional use. Such a varnish, properly formulated and made, will serve all ordinary uses and requirements.

Polishing Varnish, commonly encountered in such occupations as piano finishing, is similar in character and qualities

1950-51 Theatre Catalog, 9th Edition, Page 420