3M Marine Adhesive Sealant 5200 Fast Cure White is a fast drying, one-part polyurethane that chemically reacts with moisture to deliver strong, flexible bonds. It has excellent adhesion to wood, gel coat and fiberglass. It forms a watertight, weather-resistant seal on joints and boat hardware. In addition, its flexibility allows for dissipation of stress caused by shock, vibration, swelling or shrinking.