Page:Cyclopedia of Painting-Armstrong, George D (1908).djvu/384

376 which contains moisture will assist in producing better penetration.

In repainting an old surface, the first coat must be reduced with turpentine according to the porosity of the surface. If a hard, flinty surface, much more turpentine must be used than if porous or weather-beaten. The mixture should range from flat, half flat to semi-gloss. Never apply a heavy coating of full oil reduction.

Paint which has become fatty and gummy can be partially remedied by the addition of a small amount of turpentine. When painting in hot, humid weather, a small amount of turpentine added to the finishing coat will aid in hardening the paint.