How to Repair Gelcoat Part 1

How to Perform a Simple Non-Structural Gel Coat Repair

Gel coat is a protective outer layer applied to fiberglass surfaces like boats, jet skis, camper shells, and trailers. While durable, gel coat can still suffer from chips, gouges, and cracks. If the damage is only cosmetic and does not affect the fiberglass structure underneath, a simple repair can restore the surface. This guide covers part one of the process: preparation.

Understanding Gel Coat Damage

Chips and gouges that do not penetrate the fiberglass layers are considered cosmetic damage. These repairs focus on restoring the appearance rather than structural integrity. Cracks, however, may indicate flexing beyond the gel coat’s stretching capability. If the flexing continues, any repair will only be temporary.

Step 1: Preparation

Proper preparation is the key to a long-lasting gel coat repair. Follow these steps before applying new gel coat:

Protect the Surrounding Area

• Apply blue masking tape a couple of inches away from the damaged area.

• Blue masking tape is recommended as it does not leave adhesive residue even after several days.

Remove Loose Gel Coat

• If there are any loose or chipped pieces, carefully remove them to create a clean repair surface.

Widen Small Cracks (If Necessary)

• Narrow cracks should be widened to ensure proper bonding of the new gel coat.

• Use a scraper or a Dremel grinder to open up the crack and create a tapered edge.

• Avoid sharp edges; a tapered repair area allows for better adhesion.

Sand the Surface

• Sand the repair area to remove deep contamination and smooth the surface.

• Ensure the area is even and ready to receive new gel coat.

Clean with Acetone

• Wipe the sanded area with acetone and a clean rag to remove all contaminants.

• Use a straight wiping motion, not circular, to avoid spreading contaminants.

• Turn the rag frequently to prevent smearing residues.

Next Steps

With preparation complete, the surface is now ready for gel coat application. In part two of this guide, you will learn how to properly apply and finish the gel coat repair for a smooth, professional result.

By following these preparation steps, you ensure a strong bond between the new gel coat and the existing surface, leading to a durable and visually appealing repair.