CHAPTER VII. DEPRAVITIES OF VARNISH: GRAINING OUT--CRACKING--SWEATING--DEADENING, ETC.--PITTING--ENAMELING, ETC.--SEEDY OR SPECKY--CRAWLING--WRINKLING, ETC.--RUNS, SAGS, ETC.--RIDGING, ETC.--PERISHING--CHIPPING--FIRE CHECKS--GREENING--BLOOMING--BLISTERS--SPOTTING, ETC., ETC. GRAINING OUT.

The peculiar grain showing a condition of the surface which manifests itself after the job is finished arises from certain incompetent practices observed along in the early stages of painting, or from the use of wood not adapted to the needs of vehicle construction, as, for example, sappy or unseasoned wood. It is a principle of fine surfacing, substantiated by experience, that when a carriage body has been perfectly smoothed and leveled by the woodworker, it should be given a few hours, say four or five, before priming. This delay is to give the wood, subjected to unusual pressure during the surfacing process, an opportunity to expand and shape itself into a normal conformation. Upon high grade work it would be a good practice to first level thoroughly and set away in an unquestionably dry atmosphere for a few hours, and then have the woodworker apply a second sandpapering. Then after another interval of a few hours, prime thoroughly inside and out, top and bottom; in fact, wherever moisture might possibly find an entrance.

Graining out may come from priming too closely upon the completion of the woodworker's leveling process; or it may come from the dry wood having been exposed, after the surfacing process, to a "spell" of damp weather. The dry, porous timber absorbs enough wetness to raise the grain to such an extent that nothing short of a resurfacing will restore it to its normal smooth and perfect condition again. This wood, with its erect fibres or grain fairly visible to the eye upon a casual examination, if painted over and finished, dries out in time, and in doing so responds to the natural law of shrinkage.

Shrinkage involves a process whereby the priming, roughstuff, color, varnish, etc., apparently goes in while the grain of the wood goes out. Graining out is often due to a priming coat that is not given adequate time to dry hard and firm. This soft layer of rather slow drying pigment, if sealed from contact with the air prematurely, is a powerful inducement to grain showing. Spongy, porous roughstuff, deficient in resinous matter and weak in its binding property, is also often responsible for graining out. Good reliable priming, lead and roughstuff coats, allowed to dry thoroughly, each and all of them, arrest the graining out tendency. Improperly seasoned wood is a prolific producer of grained out surfaces.

Moisture confined under a body of paint and varnish is bound to make its exit right speedily, and this it does by voraciously sucking the paint and varnish material in and pushing the grain of the wood out.

CRACKING.

It has been said that the natural destiny of varnish is to crack. When a varnish has worn itself out, lost its elasticity, become brittle, it will, despite the best laid plans of men and science, fissure and crack. In so doing it simply responds to a natural law. The cracking that occurs prior to this period of service is of supreme concern to the painter. Probably the greatest cause of varnish cracking—the cause that towers above all other causes—is developed by the hurried system of painting—forcing one coat over another not perfectly dry. Imperfectly dried rubbing coats, or a lack of uniformity in the selection of the varnishes used, often cause cracking. For example, a quick drying rubbing varnish, or a hard drying finishing, even, is employed, over which a slow drying, elastic finishing is used. Antagonism between the varnish coats, or between the varnish and color coats; improperly adjusted foundation coats; exposure to sudden atmospheric changes, including excessive heat; the action of ammonia; poor material—all of these are underlying causes of varnish cracking. Imperfectly seasoned panels or moisture penetrating thin wood panels will tend to crack the varnish used over such surfaces. The cracks in varnish due to a continued straining of the panels are termed "force cracks."

Force cracks are usually found just over the steps on the carriage body, running in long, circular lines, also on the panels under the seat riser, and on the seat riser. The vibration of light, insecurely stiffened carriage bodies is generally a direct cause of premature cracking of varnish. The accompanying cut of a buggy body shows the usual location and sweep of force cracks. This class of surface fissures is very easily distinguished from those due to causes previously mentioned.

SWEATING.

Sweating is the taking on of a gloss after the varnish coat has been rubbed. The principal cause of varnish sweating is rubbing it before it has sufficiently hardened. Varnish laid over a coat of color or of varnish that lacks somewhat of being dry is prone to sweat. When a coat of varnish has been rubbed and allowed to stand for some time—over night, say,—in a close paint or varnish room atmosphere, it will take on a sort of a gloss or greasy scum which comes under the head of sweating. It would be in the highest degree dangerous to permanent or brilliant results to flow a coat of varnish directly over a sweaty surface. The sweat that overspreads a rubbed varnish surface by reason of the absorption of atmospheric impurities can be quickly removed by lightly rubbing with a little rotten stone and water. The sweating out of a surface rubbed before it has adequately hardened can only be remedied by allowing the surface to become hard and then re-rubbing.

DEADENING, SINKING IN, ETC.

This describes a varnish when it goes "flat," loses its lustre, and refuses to shine in the public eye. The causes of this trouble are, briefly; unseasoned timber, imperfectly dried under coats, such as, for illustration, a four-day rubbing varnish surfaced and finished over after permitting the rubbing only two days in which to dry. Porous under coats which absorb too great a percentage of the oil of the varnish cause deadening; and porous under coats, let us bear in mind, produce by far the larger share of varnish deadening.

PITTING.

Pitting transforms a film of varnish into an expanse of minute indentations or pits, and simply represents in an aggravated form what is commonly known as pin-holing. The depravity is caused by a lack of uniformity in atmospheric conditions during the drying process, such as from warm to cold, dry to moist; mixing varnish of various grades; varnishing over a sweaty surface or over imperfectly dried color or varnish coats, or in an apartment having an excessively wet floor, or during a day of unusual moisture. Pitting may also come from varnishing over a surface rubbed through to the under coats. Varnish charged with gaseous impurities, or a varnish not sufficiently ripened, is powerfully inclined to pit. Dirty varnish, sometimes ditto. Soap or grease smears will cause pitting, as will also too oily under coats. Draughts of cold air have been known to cause bad cases of pitting.

ENAMELING, SILKING, ETC.

Applied to a varnish surface when it assumes the appearance of enameled leather or silk. Varnish used upon a hot, humid, moist, sticky day often goes silky or enamels. Dog day conditions usually invite enameling or silking. Varnish put on in a cold room is liable to enamel. Brushing varnish too long, adding turpentine to it, using an oil-saturated brush or mixing different makes or grades of varnish cause the depravities here mentioned.

SEEDY OR SPECKY.

Caused by want of thoroughness in cleaning and dusting a surface preparatory to varnishing. Likewise by the skinning over of a varnish, the broken particles of the skin then working into the liquid and thence conveyed to the surface. Also by using an unripe varnish, or a chilled varnish, or by varnishing on a cold, damp day in a room not properly heated.

The "lousy" or dirty varnish brush begets the seedy, specky work. It is a fruitful cause of such work, in fact.

CRAWLING.

When a varnish, after having been spread upon a surface, contracts, picks itself up into patches, and otherwise vanishes from parts of the surface which should continue to reflect its lustre, it is said to have crawled. Causes: Putting it over a color or varnish ground not quite dry; using oil in the color-and-varnish, or using oil in the color coat to give it a decided egg-shell gloss; handling the work with greasy hands or washing it with water in the slightest degree soapy or fatty. Probably the egg-shell gloss, however, is the most prolific cause of varnish crawling. To remedy this trouble wash the work with clean water, dry off with the chamois skin, and varnish immediately.

WRINKLING, CRINKLING, ETC.

These are caused by putting on a too heavy coat of varnish, or by not dressing it out and wiping it up properly; also by using a varnish not sufficiently ripened. A varnish which shows wrinkling or crinkling while standing in a warm room may be made to assume an aggravated form of the trouble by simply transferring the work to a cold apartment. In the case of varnish wrinkling or crinkling, methods of prevention are preferable to any system of cure.

RUNS, SAGS, CURTAINS, DRAPERIES, ETC.

Some of the causes which develop the depravities outlined in the foregoing paragraph are responsible for those at the head of this one. Other causes are: Lack of uniformity in the application of the varnish, one brushful of the liquid being nicely worked out and the next one being the reverse, or the varnish being applied heavier on one part of the surface than on another, or too heavy a coat serving as the predominate feature throughout. Careless, incomplete wiping up around mouldings, bolt-heads, nuts, and fixtures of that order, generates runs, sags, etc. To reduce these deviltries, first rub with water and pulverized pumice stone. Then pare off a few shavings from a bar of common house soap, dip the rubbing pad freshly coated with pumice stone into the shreds of the alkaline compound, and rub briskly over the offending deviltry. After using the soap, rinse off with clean water very thoroughly. Then rub lightly with rotten stone and wash thoroughly.

RIDGING, ROUGHING.

These terms are given to a surface that resembles a corrugated panel, showing a ridgy, furrowy expanse. Timidity or the spirit of the painter-afraid-of-his-varnish provokes this lamentable surface condition. After the varnish has set past a certain tack and the brush is then drawn through it, roughing and ridging occurs. When one falls heir to this mishap, take a soft badger-hair brush and, procuring a small quantity of turpentine, proceed to apply the fluid plentifully over the panel. This will quickly soften the coat of varnish so that by wiping the brush carefully out, the loosened varnish can be easily brushed off and the surface immediately revarnished.

PERISHING, CRUMBLING, RUSTING.

By this we mean a gradual loss of lustre, the final result of which is a disruption of the surface ending in a complete destruction of the varnish. Washing with water heated beyond the tepid degree is an engaging bid for the disaster here noted. Ammonia fumes, coal gas, salt sea air, soil of limestone localities, etc., cause varnish to perish and crumble away.

CHIPPING, FLAKING, PEELING.

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.

SPOTTING.

There are several forms of this ailment, viz., mud spotting, soapy or dirty water spotting, and the spotting caused by strong currents of air beating powerfully upon the varnish surface. Mud spotting is by far the most malignant type of the depravity herein mentioned. An elastic high grade varnish is more susceptible to the poison contained in earthy accumulations than the hard drying or the low grade varnish.

Accumulations of mud allowed to dry upon a freshly varnished surface spot the varnish through the action of the suction or capillary attraction of the dry mud extracting the oil from the varnish. Again, the spotting may be due to actual saponification, by the alkaline mud, not only of the oil, but of the gum constituent of the varnish as well.

City mud strongly charged with ammonia, and the mud of lime districts, is notoriously destructive to varnish lustre. While it rarely happens that any sort of treatment short of rubbing off the surface and re-varnishing proves satisfactory, the trouble may now and then be effaced, temporarily, at least, by first rubbing the spots with a rag moistened with equal parts of linseed oil, turpentine, and alcohol, and then immediately polishing with a soft piece of blotting paper.

Soapy or dirty water spotting, which may be distinguished by the usually correct circle outline, is difficult, if not impossible, of effacement, especially if allowed to long remain upon the surface, as the potash and acid nature of the water takes a ready and sharp hold of the varnish. A prompt washing off with clean soft water will sometimes prove a cure. This failing, rubbing off and re-varnishing must be resorted to.

The gases generated by an ordinary coal stove or blacksmith's forge, if permitted for long to attack a varnish surface, will effect a particularly grievous type of spotting. This will manifest itself in the form of dull, lustreless spots richly suffused with a film of greasiness. The rubbing down and re-varnishing is the only reliable and sure cure for this depravity. Spotting caused by unusual or disturbing currents of air beating with moderate or fierce intensity upon a sensitive surface is met with in the shape and appearance of dull, indistinctly defined spots, irregular in form, sometimes elongated, frequently of conoidical outline. The first indications of this variety of spotting should be met with a prompt washing off with clean water and a careful drying up under the chamois skin.

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