Practical Carriage and Wagon Painting / A Treatise on the Painting of Carriages, Wagons and Sleighs, Embracing Full and Explicit Directions for Executing All Kinds of Work, Including Painting Factory Work, Lettering, Scrolling, Ornamenting, Varnishing, etc., with Many Tested Recipes and Formulas

by M. C. Hillick

THE MIXING OF COLORS,

in view of the fact that the manufacture of them has now reached a very high state of perfection, would seem to be a comparatively easy matter, but it must be understood that in vehicle painting, business vehicle painting especially, there are many hues, tints, and shades demanded which the color maker does not furnish. Such mixtures have to be prepared by the painter, and the work becomes a skilled operation. First he must be fortified with a clear knowledge of the proportions of the ingredients required to form the desired color or hue thereof, or tint or shade. Then he must skillfully and perfectly combine them. The word "perfectly" is emphasized because if the constituents be not perfectly combined, a long train of evils is invited. A most minute and perfect incorporation of all the particles of the paint material must be made, otherwise a lack of uniformity in strength, coloring, and covering power results. Certain colors have a property of unduly asserting themselves when combined with certain other colors in the mixing cup, and if allowance be not made for this assertive strength and a very thorough mixture of the parts effected, the color, when applied to the surface, is apt to show streaks. Some pigments require grinding upon the slab under the muller to obtain an absolutely perfect commingling of the particles.

This rule applies to the mixing of pigments: The more perfect the mixing, the more perfect the product; perfect not only as regards its strength, permanence, and brilliancy of color, but perfect also as regards its working properties.

While two or more pigments may mix nicely together, they may not liquify readily, and unless the workman be thorough in his mixing operations, lack of a uniform film of color ensues, a condition which later on develops the faded and bleached out surface, and in many instances the flaking and shelly one. The painter who would become a skilled mixer of pigment will insist upon exact quantitative measurements of all the ingredients he may employ, both liquids and solids, when such measurements are possible, and he will further see that the ingredients are perfectly united.

The attainment of a high average of results in the use of colors depends greatly upon the achievements of the color maker and upon the uniform quality of his product. Fineness of grinding, uniformity of color in respect to its coloring and covering power, and brilliancy, are valued essentials. It is necessary that the painter should get from the color maker not one, two, or three successive lots of color that are of standard color, tint, or shade, but every lot should correspond to the exact standard. When the painter opens a new lot of color, he desires it to be exactly like the last in every particular, provided, of course, the last lot was standard. Hence, uniformity of color, of tint, of shade, of quality throughout, is a requirement with which the color maker may properly be expected to comply. It will thus be observed that the purchase of colors is one of the really important steps leading up to fine and durable color effects.

In testing a color for covering power or opacity, for coloring strength, and for brilliancy, comparison should always be made with a strictly standard color.

To assay for covering power or opacity, weigh out, say 50 grains, of the standard color and the same number of grains of the color under examination, and to each sample add 10 grains of fine china clay, if the colors be dark, or 10 grains of the highest grade of lampblack (this being a pure black) should they be light, and mix intimately. The sample which departs the least from its own color has the best body or covering power. Or mix exactly equal quantities of the standard color and the color to be assayed, in equal quantities of raw linseed oil, incorporating the oil and the pigment thoroughly, and then apply to glass surfaces (small panes of window glass answer the purpose fully), spreading the pigment as evenly as possible. The sample covering the glass most solidly has the strongest covering power.

Coloring power is determined by mixing a given quantity of a standard sample of color with a certain quantity of china clay or, if preferred, zinc white. Of the sample to be assayed take the same quantity of color and mix with exactly the same quantity of china clay or zinc white used with the standard. The sample showing the greatest depth of color may be accepted as having the strongest coloring power.

The durability or permanency of a pigment may be tested by mixing the pigment with raw linseed oil, spreading on a piece of glass, exposing it to the rigors of the weather, and noting its condition from time to time.

The fineness of a color or pigment can be judged by rubbing the material between two thick pieces of glass or subjecting it to a powerful microscopic examination. Or a common fruit can with a tight cover may be two-thirds filled with clean water, half an ounce of color put therein, and the contents vigorously shaken. The finer the sample is ground, the longer the time it will require to settle out.

The following table is intended to aid in the compounding of the principal hues, tints, and shades of colors used in carriage and wagon painting. It would prove futile to try to make the proportions arbitrary, because the uniformity of colors advocated above does not universally obtain, the product of one firm differing from that of other firms and very often, unfortunately, lacking uniformity in itself.

Moreover, color sense has not reached a uniform development, and the proportions which would, for example, make a cherry red as accepted by one person might not appear that color to the second person. However, in most of the formulas proportions are indicated, and the table is presented not as an infallible guide, but more in the nature of a reliably helpful one.