Boat Life Caulks & Sealants

BoatLife Caulks & Sealants: Purpose-Built for the Marine Environment

When it comes to keeping water where it belongs — outside the hull — few names carry more weight on the water than BoatLife. With more than 60 years of marine chemistry behind them, BoatLife has earned a reputation as a go-to source for professional-grade caulks and sealants engineered specifically for the punishment of saltwater, sun, and constant structural movement. Browse the full Caulks & Sealants category to explore the complete range of formulas available.

Life-Calk: The Flagship Polysulfide Sealant

At the heart of the BoatLife sealant lineup is the legendary Life-Calk. This one-part, thiokol-based polysulfide sealant is a workhorse above and below the waterline, trusted by boaters for demanding jobs like bedding deck hardware, sealing thru-hull fittings, caulking teak decks, and closing underwater seams. What sets Life-Calk apart is its unique versatility: it can be sanded and painted over for a clean, finished look, and it bonds to fiberglass, wood, metal, glass, and even itself. It offers excellent resistance to teak oils, gasoline, and diesel fuel, making it equally at home in engine compartments and on exposed decks. One of its most practical features is the ability to be applied to damp surfaces and even underwater, making it a reliable choice for emergency repairs in the field.

Life-Calk is available in both Type H (heavy) and Type P (pourable) formulations, giving boaters the flexibility to choose the right consistency for the job — whether filling wide seams or working into tight joints.

LifeSeal: Silicone-Polyurethane Hybrid Technology

For fiberglass-heavy builds and applications that demand flexibility without bulk, BoatLife's LifeSeal® sealant offers a distinct approach. It is formulated as a unique combination of marine silicone and polyurethane, delivering a fast-curing, low-odor, non-sagging, non-corrosive, and non-yellowing formula. LifeSeal® is ideally suited for sealing decks to hulls, thru-hull fittings, vinyl ports, windshields, and general hardware bedding. Importantly, it can be removed without damaging gel-coat — a critical advantage when working on fiberglass boats where cosmetic integrity matters. The formula is mildew resistant, acid free, and cures in the presence of moisture, making it practical in the humid marine environment. LifeSeal® is available in white, black, clear, and aluminum finishes, with custom colors available for special-order applications.

Marine Silicone Rubber Sealant

Rounding out the lineup is BoatLife's Marine Silicone Rubber Sealant, an all-purpose 100% marine silicone that cures quickly and will not shrink, crack, or dry out over time. It retains flexibility and tensile strength even after years of UV and weather exposure, and its acid-free cure means it will not corrode the metal hardware it contacts. Available in both tube and cartridge formats, this sealant delivers solid performance for above- and below-waterline tasks across fiberglass, plastic, metal, and wood substrates.

Choosing the Right BoatLife Sealant

• Life-Calk – Best for teak decks, thru-hulls, hardware bedding, and applications requiring a paintable, sandable finish
• LifeSeal® – Best for fiberglass joints, windshields, vinyl ports, and joints with significant structural movement
• Marine Silicone – Best for general-purpose above- and below-waterline sealing where a fast-curing, flexible silicone is preferred

All BoatLife caulks and sealants are designed for the unique stresses of the marine environment — UV exposure, saltwater immersion, fuel contact, and constant hull flex — making them a trusted choice for both weekend boaters and professional marine technicians.