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.