3M Marine Adhesive Sealant 4000 UV is a one-component, medium-strength, moisture-curing, gap-filling sealant that cures to form a firm, flexible and waterproof seal on aluminum, wood, gel coat and fiberglass, making it well-suited for marine applications above or below the waterline. This product offers excellent UV resistance for reliable long term performance. Forms a skin in 30-60 minutes but can be painted over with water-based paints immediately after application. The seal is extremely strong, retains its strength above or below the water line. Stays flexible too and allows for structural movement so stress caused by shock, vibration, swelling or shrinking is effectively absorbed. Has excellent resistance to weathering and salt water. Check the bonding and sealing jobs this product can handle for you: fiberglass deck to fiberglass hull, wood to fiberglass, porthole frames and deck fittings, under mouldings, hull seams above and below water line. Stern joints. Deck housing, etc.