Pure raw linseed oil is so essentially a part of durable carriage and wagon painting that especial attention should constantly be directed to the oil supply.
In respect to his purchases of turpentine the painter should be likewise cautious and investigating. The adulteration of turpentine with headlight oil, or a lower grade of kerosene, and with 112 fire test oil has been, and continues to be, actively carried on. This 112 fire test oil, as employed in small southern distilleries not shadowed by inspectors, shows a list of ingredients closely corresponding to, heavy paraffine oil 1/3; kerosene, 1/3; light oil, 1/3. Thus a gravity is provided which registers about the same as pure turpentine and is therefore very difficult to detect. The naval authorities practice—and it is said, successfully—the old-time test of dropping the suspected turps on a piece of white paper alongside of a pure brand of turps and watching the result. The turps containing the 112 fire test oil will leave, upon evaporation, a faint but decided greasy stain. Pure turpentine not too rapidly distilled will leave no spot. The turpentine containing traces of the crude gum due to too rapid distillation will impart a sticky, yellowish-white stain to the paper and this the painter should not confound with the afore-mentioned greasy stain of the adulterated turps. In our Eastern, Middle, Western, and Northwestern cities the practice of kerosene oil injection is the favorite method of cheating the consumer. The sense of smell will sometimes detect the presence of kerosene; the white paper test will sometimes expose it; and again both tests will fail, along with the other usual ones. While so keen an authority as Mr. Geo. B. Heckel, of Drugs, Oils and Paints, has acknowledged that the adulterators can cheat the hydrometer to a certain extent, it cannot be done with the same measure of profit and impunity as formerly. Mr. Heckel has publicly advised consumers to insist on 31° turps, prefacing the advice with the following noteworthy declaration: "If I were a painter I would never accept a gallon of turpentine without sticking a hydrometer into it, and if it registered above 31 1/2° or below 30 1/2° I would not accept it from the United States Treasury."
What vehicle painter vested with the authority of purchasing the turpentine supply for a painting business, be that business big or little, can afford to disregard Mr. Heckel's admonition? To pay turpentine prices for kerosene oil is a disastrous drain upon the resources of a painting business, in addition to furnishing the materials used an element of insecurity, a germ of decay, sure to disturb the durability and comeliness of a painted surface. For it is, or should be, in fact, clearly understood that the kerosene or fire test oil adulterants do not evaporate like turpentine when put into a pigment and spread upon a surface. They strike into the wood or pierce the nether coat of pigment, causing, later on, the flaking and peeling of the pigment; or they retard the drying of colors; and again, they lend a peculiar roughness to the surface, like unto that imparted by benzine when used in a fine coach color.
The carriage and wagon painter has substantial reasons for being interested in coach japans, for upon their quality and judicious employment the durability of his work greatly depends. The many and beautiful colors which he uses almost daily are japan ground, and the pigments and colors shop-mixed are invariably fortified with the ever-useful coach japan. The wide variety of names applied to the drying materials used in the painting business has been the source of annoyance and confusion to the practical mind. In reality, however, there are but three kinds—coach japan, specially adapted for colors to be quickly dried and containing no oil; liquid drier (or dryer) intended for the drying of oil and oil paint; and patent driers purchased in paste form, effective only when used in conjunction with oil. The patent driers are so little used at present that they scarcely merit a notice.
Coach japan, with the merits of which the carriage painter has a right to be concerned, being chiefly used, as before stated, in colors containing no oil require, for purposes of protection and as a service-insuring medium, blanketing under one or more coats of varnish.
It is not to be understood that coach japan will not combine with and dry oil colors; its power in this capacity, however, is less than that of a liquid drier, while its gummy nature shows a tendency to cause surface disturbances of the cracking and blistering order—most emphatically so when strictly exact proportions are not maintained. Its adaptability, therefore, is best confined to colors containing no oil.
So much of uncertainty, so much that is injurious and fatal to the durability of colors, is embraced in the employment of japan in excessive quantities or of an inferior grade that the painter should not be slow in determining, by practical tests, both strength and quality. And to make such tests easy, not to mention other convincing reasons, need we invoke the purchaser's attention to the importance of buying only standard makes?
A first-class coach japan, as a rule, will show a color moderately light, and when mixed with oil should manifest no disposition to curdle. Such a japan, too, should, when floated in a thin film over a glass or other strictly non-porous surface, dry firm and without brittleness in four hours. To observe how the japan unites and assimilates with linseed oil, take a pane of window glass, that furnishing a surface non-porous and decidedly free from suction, and attaching a sheet of white paper on one side as a means of better showing the action of the oil and japan, drop on the reverse side of the glass about four drops of raw linseed oil. Then affix, say, a single drop of japan in close proximity to the oil, immediately inclining the glass so that the japan may come in contact with the oil. If the drier promptly unites and takes kindly to a close relationship with the oil without curdling or showing other evidences of disagreement, it will merit the approval of the painter. Another easily-conducted test consists in comparing the japan of unknown quality with one of acknowledged merit, by taking the samples and confining them in bottles containing raw linseed oil, shaking the contents and then standing aside for at least twenty-four hours. The proportions of oil and japan may be in the ratio of 5 parts of oil to 1 part of japan, exactly the same proportions being adhered to in all the samples tested. At the expiration of twenty-four hours one can see which sample mixes best with the oil. The samples then poured in a thin film over a piece of glass and allowed to stand will determine the drying property of each. It will also be useful to learn by observation and comparisons if the japan holds well in solution. A japan that fails to do this is not valuable in carriage and wagon painting. Study should be made as to how and to what extent the japan effects the light and delicate colors at present so extensively used. In point of fact, the painter should not weary in investigating the qualities and characteristics of his coach japans, and what they are capable of doing. To establish their real value will mark an achievement of the first order in the economy of painting.
In regard to varnishes the buyer can find no excuse for putting aside the fact that quality and not price should determine the value of his supply; and, happily, he has it within his power in the active prosecution of his business to demonstrate the good or bad quality of varnish. It may frequently prove an expensive experiment; and herein is disclosed an apparently good and sufficient reason for the painter's disinclination to change from the use of one make of varnish to another. The varnishing stage of painting may be said to be in a critical period at all times, and having established the quality of his varnish supply, the responsible party in the matter is naturally opposed to changing in favor of a make with which he is not practically acquainted. At the same time, a practical test of different strictly reliable makes is the only way of deciding to one's own satisfaction which is the best, and the most economical to buy. Any first-class finisher can very soon determine the working property, brilliancy, depth of lustre, drying quality and general behavior under varying circumstances and conditions of different varnishes. Nevertheless, that primary requisite, durability, is not so easily nor so promptly established. This essential quality can be determined only after protracted trials upon vehicles engaged in active service, the painter retaining carefully tabulated data bearing upon each make of varnish under observation, the character of the service to which it is exposed, etc. Thus, in due season, may the actual merits of a varnish be defined.