Zinsser Cover Stain Primer Sealer Spray Stain Blocker with Turbo Spray System is a versatile, multi-purpose formula that blocks and seals stains caused by graffiti, smoke, water damage and other sources. Ideal for medium and large-sized disaster restoration projects. Excellent bond coat for hard-to-paint surfaces such as railings, shutters, outdoor furniture and sticks to glossy paint, glass and ceramic tile.