In the above formulas keg lead is referred to.
Priming should contain just enough pigment to stain the oil. Only in this form does it perform the functions of a primer. Some hardwood surfaces, negative in composition, require a priming thinned somewhat with turpentine; otherwise such close textured spaces of wood are not sufficiently penetrated by the oily particles of the priming. The durability of the priming rests largely upon the penetration of the oil into the arteries of the wood along with a certain necessary per cent. of the pigment.
It is a good plan not to follow the surfacing of a job in the wood shop too closely with the priming. Immoderate pressure of the wood fibres usually results from the pressure of the wood worker's leveling methods. Give the wood time to expand before priming, but not time to absorb moisture. Graining out of surfaces often results from priming a surface too soon as well as too late. Many factors must necessarily be considered in order to have the priming coat do all that it should do. The condition of the wood, the climate, season, atmosphere, etc., all require diligent study. The application of the priming to the surface deserves particular attention. Granted that first-class filling and surfacing pigments, combined with liquids rich in gummy resinous matters, make the ideal primer, the coating fails of its mission when practices of neglect mark its application to the surface. Therefore, apply the priming smoothly and in a uniform film to the surface. Coat all parts of a job, outside, top, bottom—everywhere. Insist upon its being well brushed out—just as any coat of paint should be.
Putty-holder.
THE LEAD COATS.
What we shall be pleased to term "first lead" was formerly made of white (keg) lead thinned to a brushing consistency with linseed oil and turpentine, half and half. That was at a time when egg-shell gloss coats were in demand. A different principle has been established of late years in reference to the composition of the lead coats, and the egg-shell gloss is now regarded with suspicion and, to a large extent, abandoned altogether.
Consequently, the first lead should be mixed of 3/8 oil to 5/8 turps, or even with a still smaller percentage of oil if the limitations of time so direct. Apply this lead with a bristle brush and enforce rigidly the rule of smoothness and sleek brushing out.
"Second lead" means in modern paint shop lingo "flat lead"—a lead that dries to a dull, lustreless appearance, practically "dead lead." It is composed of white lead, thinned to a working consistency with turpentine, and given a binder of oil to the extent of, say 2/3 of a tablespoonful of oil to a pint of the lead. These lead coats should properly contain 1 teaspoonful of japan to a pint of the lead, and be shaded with lampblack. The flat, or dead, lead is best applied with a camel's-hair brush.