Perma-Crete® Concrete Stucco Primer. 4-503, is specifically designed for exterior, above ground, non-staining wood, fiber cement, wallboard, stucco, concrete, and masonry surfaces. Perma-Crete® 4-503 is formulated to provide a uniform seal, good holdout, adhesion, alkali and blister resistance, and mildew resistance on the dry film. This Perma-Crete® Concrete Stucco Primer is ideal for use on a variety of exterior masonry projects including apartments and condominiums, hospitals, schools, parking garages, hotels, resorts, and residential homes.