Glue Devil Marine Silicone is a premium, 100% acetoxy-based silicone sealant specifically engineered for the harshest aquatic environments. Formulated to withstand constant immersion in both fresh and saltwater, it provides a permanently flexible, high-strength seal that is resistant to UV radiation and marine degradation. Key Performance Features 100% Waterproof & Submersible: Designed to maintain its seal integrity even when permanently submerged, making it the primary choice for hull and deck fittings. Saltwater & UV Resistant: Specially stabilized to prevent cracking, shrinking, or yellowing despite prolonged exposure to harsh sunlight and corrosive marine salt. Superior Flexibility: Maintains a high degree of elasticity to accommodate the natural "flex" and vibration of boat hulls and marine structures. Excellent Multi-Surface Adhesion: Bonds powerfully to non-porous surfaces including fiberglass (GRP), glass, stainless steel, aluminum, and most coated metals. Ideal Applications Below-the-Waterline Sealing: Perfect for sealing through-hull fittings, transducers, and seacocks where a watertight bond is critical. Deck Hardware: Ideal for bedding and sealing cleats, rails, winches, and hatches to prevent leaks into the cabin. Aquariums & Fish Tanks: Safe for use in large-scale glass aquarium construction (once fully cured and rinsed), as it contains no harmful fungicides that could leach into the water. Portlights & Windows: Provides a weather-tight seal for marine windows and portlights exposed to heavy spray and wind. Product Benefits Rapid Cure Speed: Skins over quickly to protect the joint from dust and light spray shortly after application. Non-Shrinking Formula: Ensures that the seal remains tight and leak-proof over years of service. Professional Grade: The 280ml cartridge fits standard caulking guns, allowing for a smooth, pressurized bead into deep joints. Pro Tip: For the strongest marine bond, clean the application surface thoroughly with a solvent (like acetone) to remove all traces of salt, wax, or old sealant. If using on fiberglass, a light sanding of the gelcoat in the bonding area will significantly increase mechanical adhesion.