The separation of one varnish coat, or certain parts of it, from another, or from a coat of color is known as "chipping," "flaking," or "peeling." Causes: Moisture in the wood; imperfectly dried under coats; grease and smoke from the smithshop; failure to maintain the proper elasticity between the successive color or varnish coats. It is very probable that the most active and effective cause arises from the use of adulterated turpentine, inferior japan, and a poor, low quality material generally.
FIRE CHECKS.
These consist of a delicate tracery of almost invisible fissures radiating every which way. The displeasing effects of fire checks are not fully disclosed until the finishing varnish has been laid. An extra coat or two of rubbing varnish will usually suffice to conceal all traces of a moderate array of fire checks.
GREENING.
This comes from the use of too many clear rubbing or finishing coats of varnish to a black surface. Successive coats of clear rubbing varnish, capped with a heavy coat of finishing, applied over a black japan ground, affords a pronounced and, in some respects, enticing shade of green. Greening of a varnish surface is also effected by confining the freshly varnished work in a dark apartment while the drying is going on. When the work is fit to remove from the varnish drying room, in order to intensify the greening, it may be stored in a dark room or repository for a time. Recently varnished surfaces held for a few weeks in dark apartments green rapidly. Prevention: Use black color-and-varnish over black color grounds. Add a dash of black color to each of the clear rubbing coats up to and including the final rubbing. Furnish the drying room with plenty of light on all sides, and, so far as possible, insist vigorously upon the necessity of light, airy carriage houses and repositories.
BLOOMING.
Blooming is a whitish, metallic-like film, like unto the bloom on a plum or peach, which obscures the brilliancy of the varnish. It is variously known in the trade as going cloudy, smoky, or foggy. Varnish surfaces exposed to a moist atmosphere, to smoke, or to the fumes of the blacksmith shop are apt to bloom. If the blooming is of recent origin, a thorough washing and drying off with the "shammy" will generally restore the lustre of the varnish. If of long standing and therefore of a virulent type, the only effectual remedy is rubbing with pulverized pumice stone and water and re-varnishing.
BLISTERS.
The varnish surface, dry or apparently so, when afflicted with little eruptions, after the fashion of pustules on the human cuticle, is said to have blistered. The disease is caused by moisture in the wood, exposure to the intense rays of the sun during the early days of service, or to the presence of oil or grease on the surface directly under the finishing coat or between any of the preceding coats of varnish or color. Soft under coats develop blisters, their development through this medium being in this wise: Coats of lead, heavy in body, and perchance a bit fatty or gummy, are applied to the surface. Such coats do not dry thoroughly. Oil in color coats tends to the same result. They deceive the workman, being apparently dry, but not really, when choked up under subsequent coatings. A surface so builded is eventually put into service and submitted to the sunlight. Warmed by the heat, these undried particles of color or lead quickly respond to the law of expansion. The varnish, supple and full of elasticity, instead of cracking and splitting into fissures, simply swells up with the paint. Fierce stove or steam heat causes blisters. A varnish blister, if not located upon a too prominent portion of the surface, may be reduced to a surface fracture easily overlooked, by puncturing with a needle and then pressing the rupture down with a wet sponge.