Unique underwater “silicone” sealer. This sealer looks like black silicone sealer but it sticks and sets underwater. It is non-toxic and solvent free and can be used safely with fish actually in the tank / pond, fresh or saltwater. Bonds all materials even under water. Butyl Rubber Vinyl Glass Ceramic Stone Concrete Wood Gold label Underwater Sealer for Full cure needs 24 hours, initial tack 2-3 hours, can be painted over up to 4 hours.