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Boat repair professionals have relied on fibreglass for many years because of its durability and versatility. They choose it primarily for its lightweight strength.. During the course of its lifetime, all fibreglass boats will undergo maintenance to keep the boat looking its best and to ensure maximum protection. Common boat repairs undertaken by the customers of Tricel Composites are in relation to small cracks, gelcoat discolouration and patching small holes.
For the purposes of this boat repair article we will focus on patching a small hole in a fibreglass boat.
Resin (Isophthalic, Lloyds Approved, or Epoxy)
Catalyst (All resins & Gelcoats at Tricel Composites are supplied with Catalyst)
Acetone
Masking tape
Fibreglass Mat
Wet & Dry Sandpaper
Gelcoat (to match current colour)
Compound
Quantities will vary dependent on the size of the hole to be repaired.
Good preparation is critical for a successful fibreglass boat repair.
After wiping down the area to be repaired with acetone, the first step in the process is to enlarge the size of the hole to be repaired. With a disc sander and medium grit disc, grind the edges of the hole. This should be done until the outer edge of the hole is approximately 2-3 inches wider than the inside edge. This will provide a solid surface for the repair materials to bond with.
After completing this step, wipe down the area with acetone again to remove any dust or debris. If the hole goes all the way through, make sure to cover the back. For smaller repairs, tape works well. Alternatively, use a smooth, flat material that resin won’t stick to.
Ensure that it is firmly in place before continuing with the repair.
Cut layers of Chopped Strand Mat to fill the repair area. Make the first layer slightly smaller than the area to be covered, the second layer about the same size as the hole, and the third layer large enough to cover both the hole and the ground edge. Add extra layers if the repair is deeper.
Apply the first layer of the glass mat to the area and using a brush, completely saturate or ‘wet out’ with the catalysed resin. Use a paddle roller to remove any trapped air. Repeat for second and third layers.
After approximately 30 minutes, when the repair surface is tacky to touch, the area should be sanded as required.
Allow to cure completely. (If the repair is below the water line of the boat it is recommended that a period of 7 days has passed before putting the boat back into the water.)
To finish the repair, first apply a topcoat that matches the boat’s existing colour. Manufacturers offer topcoats in a standard range of colours; however, you can pigment them to match specific shades.
Next, mix the topcoat with 2% catalyst—just like you would with resin—and apply it at a thickness of approximately 1mm.
After it cures, sand the area down using Wet/Dry sandpaper to smooth the surface.
As a result, the topcoat will provide enhanced protection against weathering and offer greater scratch resistance.
Finally, once applied correctly, the finished fibreglass repair will be strong and durable—ready to withstand the harsh conditions of the sea!
Tricel Composites brings over 40 years of experience to the fibreglass industry. We keep all our materials in stock and ready for immediate dispatch.
If you need more technical information about anything in this article or have questions about upcoming DIY boat projects, feel free to get in touch—we’re here to help.
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