To repaint tacky seats the best way is to burn off the old paint, and coat up as above; because, if a hard drying paint is put over the old soft paint it is liable to crack. It is well, however, to see if the turpentine and japan will work a cure, or if a coat of shellac will stop the trouble. To do this it is well to first experiment on one seat, or upon a small surface.
I have killed tacky paint by rubbing it with a cloth wet with ammonia; when dry, try it, and see if the “tack” is gone; if not, go over it again; when dry, put on a coat of shellac varnish; this is a pretty sure cure.
TESTING JAPAN.
If japan smells of benzine don’t buy it. Mix it with clear oil; if it curdles, you don’t want it. Mix drop black with some of it; as stiff as good drop black ground in japan; then thin with turps and make a painting test, to see if it is a good binder. To see if it will crack, paint on glass, let it dry and hold the glass between your eye and the light. If you see fine cracks don’t buy any of it.
When you go to buy japan, ask the dealer who made it. If he don’t know, make up your mind at once that it is a fatherless waif without a name, and likely to be worthless. When a man makes a good thing he is apt to send his name along with it as an advertisement. This applies to all material. There is a great deal of bad japan on the market, and a great amount of work ruined by it. Buy none unless it bears the brand of a reputable maker and will stand these tests.
I do not need to tell the practical painter that there is a great amount of bad japan on the market, and that a great deal of paint is ruined by it. Buy no japan unless the can bears the name of some reputable manufacturer, and will stand the above tests.
WHY DO PAINTS AND VARNISHES CRACK?
The following paper was read by Mr. A. P. Sweet, of Iona, Mich., at a meeting of master car painters:
SUBJECT:
“Why do paints and varnishes crack, and what is the reason that cracks in the latter are usually at right angles to the grain of the wood?”