General Purpose Polyurethane Sealant A fast curing, one-part, medium strength, polyurethane that chemically reacts with moisture to deliver strong, flexible bonds to wood, gelcoat and fiberglass. It forms watertight, weather-resistant seals on joints and boat hardware above and below the waterline. In addition, its flexibility allows for dissipation of stress caused by shock, vibration, swelling or shrinking. 3M Adhesive/Sealant Fast Cure 4200 is designed to allow disassembly of wood and fiberglass parts bonded together. If a permanent bond is desired, use 3M 5200 or Fast Cure 5200. 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. Features: Fast cure formula Allows for disassembly Non-sagging Do not use in high temperature applications (>190°F) Use for sealing purposes only on glass or metals (prime first) and some plastics (test first) Not recommended for the installation of glass, polycarbonate or acrylic windows unless they are also mechanically fastened Sealant should be used within 24 hours after inner seal is punctured, as product will start to cure in thecartridge and nozzle Sandable, paintable - but test first for compatibility; sealant is more flexible than most paints, do not paint in high elongation applications