Gelcoat, Resins and Fillers

Gelcoat protects the boat's structure, but impacts, UV rays, and general wear leave it vulnerable. Material selection is critical: using a resin that is incompatible with the existing substrate causes delamination or chemical reactions. The success of a repair depends on correct layering technique and proper surface preparation.

At Nautiba, our technical approach prevents compatibility errors. We know what it means to have the boat hauled out with materials that will not bond. Before every shipment, we verify that the product chosen is correct for the type of damage at hand - whether it is a cosmetic gelcoat touch-up or structural work with epoxy resin, we guide you with clarity.

We manage supply with reliable lead times, making sure you know when the material will be available. Our goal is not to sell the most expensive product, but the one that guarantees the chemical and mechanical integrity for your specific need. If you have doubts about compatibility between the existing gelcoat and the new resin, contact us before purchasing.

Choosing the right material for restoration

A correct repair starts with analyzing the substrate and understanding the type of damage. There is no universal product, only the right sequence of steps.

• Verify the nature of the substrate: an epoxy repair on an old polyester base requires thorough sanding and a specific adhesion primer.
• Consider exposure: for the hull bottom subject to osmosis, epoxy resin is the technically correct choice due to its hydrolysis resistance.
• Factor in temperature: most resins require conditions between 15 and 25 degrees Celsius for proper cure.
• Use epoxy fillers for structural loads and gelcoat only for surface cosmetics, never to fill deep voids.

Can gelcoat be applied over an epoxy resin repair?

Technically no - gelcoat does not bond well directly onto a cured epoxy resin surface. If you intend to finish a repair with gelcoat, you must first apply a specific primer to bridge the two materials, or use compatible two-component finishing products.

How do I tell epoxy resin from polyester resin?

Epoxy has superior adhesion and greater water resistance, making it suitable for structural repairs. Polyester is less expensive and cures faster, but is less resistant to chemical agents and less waterproof.

What should I check before ordering resin?

Check the technical datasheet for pot life (working time after mixing) and total cure time. Also verify whether the product requires a specific catalyst ratio, as an error in dosage would compromise the resin's final stability.