How to Fix A Fiberglass Boat

Knowing how to fix a fiberglass boat can open up many opportunities to enjoy a sailboat or powerboat that may have otherwise been too expensive to obtain. Just like buying a beat-up car or a rundown house to fix up, a boat with damaged or even heavily-aged fiberglass can be purchased well below its market value and then fixed up with minimal investment. A few cosmetic changes to an otherwise sound vessel can make a big difference in its functionality and appeal. Careful consideration should be taken if more serious problems are present, such as blistering in the fiberglass layers of the hull.

1. To deal with a blistered hull, the boat will need to be hauled to dry land. Each blister should be ground down to clean, solid fiberglass, then sanded smooth. The hull should then be allowed to dry for days or weeks until the hull material’s moisture level reaches about fourteen percent. This value can be measured with a moisture meter. Most boat yards have one that can be borrowed if the work is being done in their yard. A boat yard may also have several boat builders that may be happy to share tips on repairing your fiberglass hull.
2. If the boat is located in a particularly humid climate, drying can be aided by swabbing each repaired blister with denatured alcohol. The evaporating alcohol will help carry away excess moisture.
3. After the hull is dry, wipe each blister with acetone and then apply a thickened coat of marine epoxy. Allow each coat of epoxy to dry and then reapply until the blister is filled flush with the hull’s surface. Sand the repairs smooth, wipe with acetone, then apply a clear coat of epoxy resin over each repair.
4. Sand the clear coat epoxy to roughen the surface so it will hold paint, then apply an anti-fouling paint to the hull. Many marina boat yards do not allow boat owners to do their own work in the yard, so be sure to check first before having your fiberglass boat hauled. Knowing how to fix your fiberglass boat can save you money better spent on fishing gear or boat fuel.