Coach Painting.

Scientific American 39, 9.6.1855

(For the Scientific American.)

It is by no means as a bone of contention that prompts us to pen the present communication, to meet the almost countless number of eyes which weekly peruse the contents of your highly popular journal, but a desire to correct, with friendly feeling, a most novel error, found on page 250 SCIENTIFIC AMERICAN, of which A. W. II., of Platte City, Mo., is the author.

Every varnish manufacturer in the Union will agree with us in the assertion that copal and coach varnish are not the same thing, being, in part composed of entirely different materials. There is still another kind of varnish used in coach painting, called "body varnish," which also differs from the two former.

But what we wish to notice more particularly is the following direction for painting coach bodies, which we quote from the article above referred to:
"For filling or priming carriage or buggy bodies, grind yellow ocher with linseed oil quite stiff, add drier in proportion, about half a pint to a gallon of paint; thin with turpentine, or use oil well boiled with a quarter of a pound of litharge to the gallon, and use no other drier. Put on three coats of this paint, giving time to dry hard, and sandpaper well between coats. When thoroughly dry and hard, rub down with pulverized pumice stone and water; use a piece of wool hat or thick cloth for rubbing. Then put on three coats of copal (best coach) varnish, rubbing down between the coats with a coarse linen cloth," &c. &c.

As A. W. H. is desirous of having coach painters to comprehend the general principles of the art, we would most respectfully submit the following to his careful consideration:

PAINT FILLING FOR CARRIAGE BODIES

Take 1 lb. yellow oaka, 2 oz. white lead, 2-3 teacupfull of drier, half a teacupfull of copal varnish, 2 tablespoonsfull of boiled linseed oil. Reduce with spirits of turpentine to the thickness of cream, when it is run through the mill, and is then ready for applying to the body. This paint in all cases is applied to the work in as thick and heavy a state as to make it work, never thinner than the thickness above mentioned; after the body has been puttied up, and received two coats of lead paint, mixed as follows: to 1 lb. white lead add half an oz. lampblack, twothirds of a teacupfull of drier, half a teacupfull of boiled oil, and reduce with turpentine,—it is ready for the application of the paint filling.

However, it is considered proper by most painters to sandpaper each coat of lead paint when thoroughly dry. But in no case is the paint filling thus treated. In applying this latter paint, the body should stand at least 24 hours between coats; from two to five coats are required, according to the grain of the wood to which it is applied; when sufficiently hard, rub down with pumice stone and water. To accomplish this, take a small piece of pumice stone, with a flat surface ground upon it; this hold in the right hand, and in the left a sponge filled with water, the water being permitted to flow upon the parts you are rubbing with the stone. Thus a perfectly smooth and level surface is cut upon the body. This done, the work is cleaned off, and then dry a thin coat of lead paint is again applied, which latter being smoothly rubbed down with fine sand paper, the body is ready for the color. This applied, the next step in order is the application of the varnish, which is afterwards rubbed down with pulverised pumice stone and water; and if a polish is desired, this latter process is followed with rotten stone and water, cleaned, off with a fine peace of buckskin, and finished by rubbing the surface well with a fine article of sweet oil.

We would here remark, that by attempting to rub down the paint filling with pulverized pumice stone and cloth, it would be found that the desired effect could not be attained, as it would simply smooth the surface, but not cut it down and make it level.

Pulverized pumice stone is never used by experienced painters for any other purpose than for cutting down the varnish. Again, coach painters, never use a coarse linen cloth for rubbing off the varnish, as that will scratch the painting.

Persons should indeed (using the concluding expression of A. W. II.) "learn the qualities and nature of all the articles used in in paints and varnishes, in order to do good work;" and we may add, that it is of equal importance that they perfectly understand the proper manner of applying the same.

— Editor Coachmaker's Magazine