Rust-Oleum LeakSeal Flexible Rubber Coating spray effectively fills and seals leaks and cracks, providing a flexible water-tight seal that prevents moisture penetration, rust and corrosion. It has a high-build formula specifically developed to fill cracks, gaps and holes while maintaining superior flexibility even with temperature changes and UV radiation. LeakSeal contains twice the solids of competitive coatings to quickly build a durable barrier and maintains its flexibility so it can be used to seal leaks and cracks on metal, vinyl, plastic, PVC, concrete and other surfaces year round. LeakSeal can be used to seal skylights, roofs, ductwork, vinyl, plastic, metal roofs and vents. Ideal for both homeowners and maintenance professionals, it is also great for use on gutters, downspouts, pipes, air conditioner drip pans and units, PVC, metal buildings and sheds, flashing, shingles, concrete foundations and more. LeakSeal dries to a semi-smooth, firm black finish that will not sag or drip and can be top-coated with any latex or alkyd based paint.