Other Coating Varnish

¶ Color Varnishes. The carriage painter, and following him the automobile painter, used rubbing varnishes which contained some color. One or several coats of clear rubbing varnish were put on and then one or more coats of the same varnish containing a few ounces of japan color were put on before the finishing varnish coats. These color varnishes were mixed by the painter and also were supplied by manufacturers ready to use with just the right amount of color pigment in them. Of course when color varnishes are made with opaque pigments instead of transparent they really ought to be classed as enamels.

¶ Brush-keeper Varnish. This material is made for use in tanks in which varnish brushes are stored when not in use. It is a long-oil varnish made without driers so that it will not skin over or dry in skins on the ferrules and bristles of the brushes. Varnish brushes should not be kept in oil baths.

¶ Rubbing Varnish. Short-oil varnishes, which necessarily dry quite hard and which have the special characteristic of being capable of withstanding considerable rubbing with pumice stone and water or oil to smooth up and polish the surface, also to cut down any inequalities, roughness and grit accumulations. Rubbing varnish must also be capable of withstanding considerable use of water or oil in the rubbing process without injury to itself. It must cut off sharp and not gum up the sandpaper like a long-oil, very elastic varnish will do. It must also take on a polish by friction of rubbing with rotten stone and must not be injured by the friction heat generated by rubbing with pumice stone. Some varnishes, when rubbed, soften up from the heat generated, some absorb the moisture or oil and take on a white clouded effect or they gum up by the rubbing instead of cutting down smoothly. Rubbing varnish is always used for undercoats, never for finishing coats. If used on top of more elastic coats cracking, crazing or alligatoring is bound to result. You can rub nearly any varnish enough to remove the gloss when it is really dry.

¶ Finishing Varnish. Usually refers to furniture or automobile or carriage varnish. Any varnish used for the final coat or coats, and which is tough and more elastic than the undercoats of varnish. Usually finishing varnish is able to withstand light rubbing with pumice stone and oil and polishing with rotten stone for a high gloss effect. Piano polishing varnishes are of this class, as also are the automobile and carriage body and chassis or gear finishing varnish. They are of the medium-oil content class, having more oil in proportion to the amount of gums contained than the short-oil class, but less oil than the long-oil spar and exterior varnishes.

¶ Polishing Varnish. Finishing varnishes, as described above, capable of taking on a much greater gloss after rubbing with pumice and oil and polishing with rotten stone on the bare hand palm. Usually refers to fine piano and furniture varnishes.

¶ Flaming Varnish. Finishing varnishes made to dry with a very high gloss without being subjected to the rubbing and hand polishing processes. Flowing varnishes are usually flowed on more freely than other finishing varnishes; they must have the characteristic of flowing together and leveling up to obliterate brush marks. It must also dry, when spread to a uniformly thick film, without runs and sags.

¶ Piano Varnish. Fine quality varnish which will dry with a high gloss. It has an unusually hard surface and will take on a brilliant lustre when rubbed with pumice stone and polished with rotten stone.

¶ Hard-Oil Varnish. The first methods employed for finishing wood were those by which hot or cold linseed oil was applied and rubbed into the wood, coat after coat being applied. It was a beautiful finish after years of exposure but the new jobs collected dust too much to be satisfactory. It was a soft-oil finish. So to overcome this defect oils or thin varnishes were made which dried with a hard finish while at the same time giving the effect of the soft-oil rubbing. From that point on the term hard-oil took on a general meaning which includes most any kind of cheap thin varnish for interior use.

¶ Sealing and Suction Varnishes. These are cheap varnishes made for use as sizes for plaster walls or other surfaces to save coats of paint. As the names imply, they are designed to stop suction and seal up the pores of the surface so that the paint coats will not soak into the surface. They are much inferior to first class varnishes thinned with turpentine and used for that purpose. A high grade floor varnish thinned with turpentine is the best and cheapest size of this kind in the long run and the first cost is little because not much varnish is needed.

¶ Gloss Oil Varnish. This is a cheap varnish made for temporary work such as coating barrels and similar surfaces. As a rule it is made of rosin and benzine or naphtha. It is very brittle, hard and crumbles easily. It is the poorest kind of a foundation for subsequent coats of paint or varnish.

¶ Church Pew and Chair Varnishes. Considerable difficulty has always been experienced because the varnish used on these surfaces often remain tacky or sticky. When used under proper conditions this trouble will not occur with ordinary good interior varnishes, but because the conditions of service are often not what they should be, special varnishes are made which will dry hard in spite of improper use, The ventilation in churches is not good;they are too often closed up without circulation of air from one week end to another, Then there is often more or less dampness, and the stale air resulting from crowds of people is likewise detrimental to varnish. Finishers who paint or grain church pews sometimes use too much oil in the under coats and so when the varnish goes on top of an oily foundation hard drying is quite impossible. The under coats of such jobs should contain the least possible amount of oil and each and every coat should be allowed to become bone dry before the next coat goes on. "When the under coats contain little oil, when they are allowed to dry properly and when the ventilation in the rooms is fair, any good interior varnish will serve for the finishing coats without remaining tacky and sticky. Tacky surfaces may often be overcome, once they occur, by spreading on a thin coat of shellac over the varnish.

¶ The special church-pew and chair varnishes have good flowing properties, dry rather rapidly, are quite elastic, have fair gloss and dry real hard. They do not soften by the temperature from contact with the human body.

¶ Mixing Varnishes. These varnishes are made for the purpose of imparting a high gloss to paints and enamels "when mixed with them by the painter or the manufacturer. They also make a much harder surface on the coatings in which they are used. Good mixing varnish will mix with paints and enamels without any unfavorable reactions with any of the other contents of the coating, and will not separate after mixing.

¶ Grinding Varnish. Many compositions are included within this group. Such varnishes and japans as are used for grinding with colors for making what the painters call japan colors and for making flat wall paints and enamel under coats are included in this group.

¶ Flat-Mixing Varnish. Since the advent of prepared flat wall paints for interior use, this flat-mixing varnish has been marketed. It is a varnish which may be mixed with lithopone and other pigments and has the property of drying without gloss while at the same time it binds the pigments together and to the wall.

¶ Dipping Varnish. In many factories merchandise, furniture, toys, etc., are finished by dipping in tanks of varnish. That saves much time required for brushing and produces a coating without brush marks and a cleaner surface. The dipping varnish used for this purpose is more fluid, it is thinner than brushing varnishes and has the property of draining off clean. The bottom or drip edge is usually wiped off clean with a soft brush after draining so as to avoid a fat edge.

¶ Gear and Chassis Varnish. Varnishes made for use on the wheels and running gear of carriages wagons and automobiles come within this class. They are the finishing varnishes for these surfaces and so are applied over color coats. They are elastic, have good gloss and are very durable, being able to resist the action of mud, water, oil, grease and dust.

Next Page: Shellac Varnish & Finish.