Rust-Oleum LeakSeal™ is an easy-to-use, rubberized protective utility coating designed to fill and seal leaks and cracks. It provides a water-tight, flexible seal that prevents moisture penetration, rust and corrosion. LeakSeal™ dries to a semi-smooth, firm finish that will not sag or drip, and can be top-coated with latex or oil-based paints.