TotalBoat 42 Million is a fast cure marine adhesive sealant, with a professional-grade polyurethane formula for strong, flexible, semi permanent bonds on boats and RVs. Creates strong, flexible, semi-permanent bonds above and below the waterline. Use 42 Million on just about every surface; fiberglass, gelcoat, wood, metal, glass, and even some plastics. The semi-permanent formula is perfect for sealing deck hardware, hatches, thru hulls, railing, fittings, and other components that may need removal for repair or replacement in the future. This marine sealant cures quickly; it's tack-free in just 30-50 minutes, forms a watertight bond in 24 hours, and reaches full cure in 3-5 days. The fast cure formula means repairs take less time, and get you back out on the water sooner. 42 Million is unaffected by saltwater, continuous sunlight exposure, vibration, moisture, or temperature changes. The 10 oz cartridge fits all standard caulking guns, and is easy to apply. Once fully cured, this ultra dependable, weather-resistant sealant lasts for years in tough conditions, but can be removed as needed. Compare to 3M 4200 Marine Sealant, Sikfaflex, Berkland, and Fortivo.