A one-part general purpose polyurethane that chemically reacts with moisture to deliver flexible bonds with good adhesion to wood, fibreglass, gelcoat, certain plastics and metals. Paintable and sandable. Forms watertight, weather-resistant seals on joints and boat hardware above or below the waterline. This product is approximately half the strength of 3M™ Marine Adhesive/Sealant 5200, which allows for disassembly of parts. Note: Not recommended for sealing wood decks because it may be permanently softened by certain teak cleaners or sealers. On plastics, test 3M™ Marine Adhesive/Sealant Fast Cure 4200 to determine suitability.