Page:Popular Science Monthly Volume 88.djvu/662

 A Can of Paint and How to Use It

��By H. A. Gardner Assistant Director, Institute of Industrial Research, Washington, D. C.

��PREPARED paints, contained in sealed packages, are the most economical and convenient. The brand selected should be composed of pigment and liquid, the pigment being white lead (corroded or sublimed) ad- mixed with zinc oxide, with or without a small amount of chemically inert pig- ments. These pigments should be ground in a liquid composed of linseed oil with a small amount of drier and thin- ner. Small amounts of color pigments have been added to such mixtures, if the paint is tinted. These paints are suita- ble for the exteriors of all wooden struc- tures.

If the painter desires using a paint mixed by hand, paste paints may be ob- tained either in the form of white lead ground in oil or zinc oxide ground in oil, which may be mixed together, or pur- chased in the form of a paste paint made of these two pigments. It is c'us- tomar}' to add to lOO lbs. of a paste paint from 4 to 6 gallons of linseed oil and a pint of liquid drier. The mixture may be thoroughly stirred in a barrel or tub. Labor and time are necessary to produce a smooth paste. Loss by spat- tering should be avoided, if possible. A gallon or more of turpentine may be used to take the place of part of the oil for first-coat work. If a colored paint is desired, color ground in oil may be added to produce the desired result. The paint should then be stirred for half an hour or so in an endeavor to get the color thoroughly into the mass in order to prevent streaking.

What Color Shall I Paint My House?

The color of a paint to be selected for a house requires consideration. In many rural localities, white paints are used, and they contrast pleasantly with the green of the surrounding foliage. It must be remembered, however, that white paints which have been tinted, by grinding into them small percentages of

��permanent colors, are more economical to use, since the wearing value of these tinted paints is from 30% to 60% great- er than the wearing value of whiet paints. For instance, if a white paint is applied to one house and a similar white paint, tinted with say 3% or 4% of color, is applied to another house in the same locality at the same period of time, the surface painted white will probably require repainting at the end of a period of three years, while the sur- face painted with the colored paint will be in an excellent state of preservation and will probably not require repainting for two more years. Therefore tinted paints should be used whenever durabil- ity is the commanding consideration. The property owner should also remem- ber that the lighter shades or tints are in many instances best adapted, since the lighter colors reflect the heat rays from the sun, while the darker colors, such as dark red, dark blue and very dark gray absorb the heat. For this reason, a house painted in light colors will be cooler in the summer than one painted in very dark colors.

Before the paint is applied, the wooden surface must be freed from moisture. If new, weathering of the wood for a short period is generally advisable in order to allow thorough seasoning and drying-out of absorbed moisture. Paint- ing should never be done in damp weather. A successful job depends upon the application of the paint during clear dry days. If the wood has not been painted before, any visible sap streaks or knots should be brushed with turpen- tine just before applying the paint. This treatment will soften the resin in the wood and allow the priming or first coat of paint to soak thoroughly into and combine with the resin, thus pre- venting scaling. For the priming coat, there should be added to a gallon of pre- pared paint from 2 to 4 pints of turpen- tine, or benzol when obtainable. The

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