Boatlife Silicone Rubber Sealant is all-purpose, non-corrosive, non-yellowing, mildew-resistant and low-odor. This sealant is tack-free in 30 minutes or less and fully cured in 24 hours. For use above or below the waterline. Superior flexibility and adhesion to fiberglass, plastic, metal and wood. Acid free cure will not corrode metal.Will not shrink, crack, dry out or yellowRetains hardness, flexibility and tensile strength through years of exposureNot sandable or paintable