Best Epoxy Fillers for Boats: Top Marine Repair Compounds You Can Trust
For boat owners and marine craftsmen, selecting the right epoxy filler is a crucial step in structural repair, deck bonding, and hull cosmetic work. This guide highlights five marine-grade epoxy fillers and kits that withstand water exposure, provide strong adhesion, and finish smoothly. Each option below is drawn from trusted marine brands and tailored for fiberglass, wood, and metal applications. The table below offers a quick snapshot of the featured products.
| Product | Brand | Type | Typical Use |
|---|---|---|---|
| TotalBoat Polyester Structural Repair Putty | TotalBoat | Fiber-reinforced polyester putty | High-strength structural filling and bonding |
| TotalBoat Thixo (185ml Cartridge) | TotalBoat | Thickened epoxy adhesive | Structural bonding, gluing, sealing, filling |
| TotalBoat High Performance Epoxy Kit | TotalBoat | Epoxy resin and hardener kit | Woodworking, laminating, repairs |
| TotalBoat Fixwood Epoxy Putty | TotalBoat | Marine epoxy putty | Stainable wood repair and replacement |
| Ankita Marine Fiberglass Repair Kit | Ankita | Fiberglass repair kit | Gel coat and fiberglass hole/ chip repair |
TotalBoat Polyester Structural Repair Putty
This pre-thickened, fiber-reinforced polyester putty is designed for high-strength structural filling, fitting, bonding, bedding, and radius forming. It suits boat building and repair on fiberglass, wood, metal, and core materials, and is appropriate above or below the waterline. The formula uses premium polyester resin with long strand glass fibers to boost strength, impact resistance, and elasticity. It’s ideal for bonding decks, stringers, and liners to hulls, as well as filleting and bonding bulkheads, and filling screw and bolt holes, chips, and dents. The mix is easy to apply and resists sagging. For a 100 g mass, catalyze with 1% MEKP to yield about 15–20 minutes of working time at 70°F; adjust catalyst to control cure time.
TotalBoat Thixo (185ml Cartridge)
Thixo is a high-strength, two-part thickened epoxy adhesive delivered in a 185 ml cartridge for structural bonding, gluing, filling, and sealing. It cures to a robust bond that can be drilled, sanded, and painted, and it is 100% waterproof. The cartridge design provides a no-mess 2:1 mix ratio with included tips, making it convenient for use on overhead or vertical surfaces where sagging can be a concern. It’s designed to wet out fiberglass effectively while maintaining a thickened consistency for vertical applications.
TotalBoat High Performance Epoxy Kit
This kit includes low-viscosity resin and a clear, non-blushing hardener for woodworking, boat building, laminating, and repairs. It supports clear coating projects and offers a simple 2:1 resin-to-hardener mix. The non-blush formula eliminates washdowns between coats, speeding up completion. It features low odor and low VOCs for indoor work. Available with Slow, Medium, or Fast hardeners to control working time and cure rate, making it flexible for various project scales. The cured surface is BPA-free and safer for potential food contact during certain uses.
TotalBoat Fixwood Epoxy Putty
This marine-grade two-part epoxy putty is designed for permanent repairs to rotted, missing, or damaged wood, including soft wood and dry rot. It’s easy to use: mix in equal parts, mold to shape, and it stays in place on vertical surfaces. The filler won’t sag, shrink, or crack, and it’s suitable for interior and exterior use. It repairs wood stairs, doors, frames, fascia boards, rafters, sills, hinges, ladders, and deck boards, among other structures, offering a wide range of applications for long-lasting fixes.
Ankita Marine Fiberglass Repair Kit
This fiberglass repair kit provides gel coat repair and epoxy filler for holes, chips, and deep cracks. It cures to a glass-hard, glossy, smooth, non-run, and non-sag finish suitable for both above and below the waterline. The repair kit emphasizes durable results under sun exposure, with fast curing and high fill-rate performance designed to withstand marine environments and shocks across boats, jet skis, yachts, and other watercraft.
Buying Guide
Key considerations when choosing an epoxy filler for boats include compatibility with substrate (fiberglass, wood, metal), water exposure, cure time, sag resistance, and finish quality. Thicker, thixotropic formulations excel for vertical surfaces and overhead work, while clear, low-odor epoxies suit indoor shops and fine laminating. For structural repairs, prioritize products with strong bonding, glass fiber reinforcement, or high-fill capabilities. If you need deep pours or casting, select a resin system designed for deep pours with clear, glass-like finishes. Always follow ventilation and safety guidelines when handling resins and hardeners, and test on small areas before full-scale application.
Two common approaches are (1) using a filler putty for quick, durable wood or deck repairs, and (2) employing a two-part epoxy kit for bonding, sealing, and long-term repairs on multiple substrates. For each project, consider cure time relative to climate, surface temperature, and working time. Safety data sheets and product labels provide precise mixing ratios, pot life, and recoating windows, which helps minimize humidity or temperature-related issues during application.
Comparing the options above, you can mix and match fillers for different repair needs—structural bonds with Thixo or polyester putty for high-strength fills, single-component epoxy adhesives for quick joints, and putty or gel-coat repair kits for cosmetically demanding surfaces. Evaluating project requirements—whether you need ultra-smooth fills, waterproof bonding, or above/below-waterline performance—will guide the best overall choice for your marine repair toolbox.