When "Prepared Mixed Paints" in paste form are used, the limit of inert pigments should be 15 per cent. This percentage may be composed of barytes, silica, or asbestine, or a mixture of such pigments. To this amount there should be no objection, as up to that extent, these inerts have their values as part of a good paint film; but vehicle proportions as set forth should be followed.
The use of asbestine is principally to hold up in suspension the heavier pigments in the paint, its fluffy and rod-like form being valuable for this purpose. It is also said to act as a reinforcing pigment in the same way that iron bars act in reinforcing concrete structures.
Straight white lead makes a splendid primer. Ochre should never be used, nor boiled linseed oil for undercoatings. When the color of the finishing coat is required to be a strong solid color such as green, red, etc., by using these strong colored paints from the foundation up, you will not get a solidity of body; therefore I would suggest the use of a strong tinted white base for undercoatings.
In the painting of cypress and Southern yellow pine, the vehicle in the priming coat, and priming coat only, should be 40 per cent of 160 degree benzole, 10 per cent pure spirits of turpentine, and 50 per cent pure raw linseed oil, proceeding with the subsequent coat as specified above. The character of these woods is such as will not permit of the penetration of paint made by the usual vehicle practice. With the turpentine and the addition of benzole, which is one of the greatest penetrating solvents of rosin, gums, and grease known, they carry the oil and pigment, when well brushed out, into the wood; and it there finds a lodgment, forming a substantial and permanent foundation for the subsequent coatings. The benzole, like turpentine, after performing its mission, evaporates entirely, leaving no residue.
From the beginning to the finish of a first-class residence, or other important operation, considerable time may elapse, not infrequently a year or more, therefore a necessity for the additional or fourth coat of paint. I would recommend for their distribution, after the priming or first coat and the necessary puttying up, that the second coat be applied, the third and fourth coats about the time of completion of building. Another sub
stantial reason for the fourth coat is that the householder, realizing that he has a new residence, is usually less watchful as to any necessity for repainting for a term of years.
With the application of the priming coat when the work is first put in place, followed by the two coats probably six months or a year after, such a condition will of necessity require repainting in probably less than four years. This proves the economy of the fourth coat, which, under average conditions, lasts as a protective agency for probably six or seven years before the necessity for repainting arises.
The basic paint pigments should be as specified in "Note 1." The proportions of vehicles for first coat must be determined by conditions. For instance, if the vehicle of the old paint coatings is dried out, leaving an absorbing surface, hungry as it were, the vehicle for first coat should consist of about 75 per cent raw linseed oil and 25 per cent turpentine, second or final coat 90 per cent raw linseed oil and 10 per cent turpentine; or, if the surface be hard and non-absorbing, the proper proportions of vehicle for first coat should be about 50 per cent oil and 50 per cent turpentine, the final coat 90 per cent oil and 10 per cent turpentine. Not infrequently I have found it necessary in repainting, from a number of causes, to give all of the woodwork three coats.
The overcoming of these imperfect conditions and producing the best results possible, is largely a work of diagnosis consisting of about 75 per cent man and 25 per cent material. The remedy for the different ailments consists in the different proportions of the vehicle to meet the diversified conditions, and not with the pigments.