Page:Cyclopedia of Painting-Armstrong, George D (1908).djvu/403



There are certain times of the year when outside painting should not be done if satisfactory results are to be expected. If painting is done too early in the spring, the surface is very apt to be full of frost and moisture and the pores closed through contraction, thus producing uneven absorption. The side of the building exposed to the heat of the sun will expand and the pores open to a greater extent than the protected side of the building. All paints and oils are much heavier in cold than in warm weather, and if applied under a low temperature there is apt to be too heavy a coat over a contracted surface, which will crack through expansion under the summer heat.

Do not paint after a frost or in early spring when frost is leaving the ground, filling every part of the building with dampness. Remember that heat ascends and brings the dampness with it.

Paint should never be applied to extremely hot surfaces. Paint applied under extreme heat sets and dries very rapidly, and under the direct heat of the sun's rays is very apt to blister, especially on old work. Remember that tints absorb while white reflects heat, and when it is too hot to paint with white, remember it is also too hot to paint with tints. This should not be taken as an argument against summer painting, but only as a caution against working on extremely hot surfaces.

In spring painting follow the sun with your work. In summer painting let the sun follow you. Switch your work according to the time of the day.

Do not paint while the plaster is drying out; allow time for it to harden through. Remember there are 80 to 90 gallons of water used in every 100 yards of plastering, most