3M™ Marine Adhesive Sealant Fast Cure 4200FC is a multi-purpose adhesive sealant made specifically for the marine market. This medium-strength adhesive forms a weather-resistant seal that still allows for disassembly. It's unique formula reacts with moisture to cure fast, forming a tack-free skin in 1 hour and fully curing in 24. Ideal for use above and below the waterline, it reliably bonds dissimilar materials including wood, fiberglass, gelcoat, plastics, and metals. Polyurethane sealants such as this form permanently flexible, elastomeric bonds that seal against the elements, maintain joint movement, and absorb stress caused by shock, vibration, swelling or shrinking. Such durability, versatility, and flexibility prepare 3M™ Marine Adhesive Sealant Fast Cure 4200FC for tough applications like sealing portholes, deck/hull fittings, rub rail attachment, screw holes, and stanchion supports.