How to Prevent Fiberglass Blistering

Fiberglass blistering is a problem all too common for boat owners.

Fiberglass blistering is an all-too-common problem for boaters and those people with fiberglass that comes into contact with water often. The cause of the blistering is simple to understand--the fiberglass absorbs water and begins to blister. The way to treat this problem, on the other hand, is more difficult. This issue is not only unsightly but can also lead to structural weakness if left untreated, so it is in your best interest to prevent blisters before they happen.

Things You'll Need

• Epoxy sealer
• Epoxy filler
• Sander
• Paintbrush

Instructions

Fiberglass Blister Prevention

1. Use a paintbrush to apply a layer of epoxy sealer to any parts of the fiberglass that have blistered or are now exposed to the water (i.e., the old sealer has worn away). Let the sealer dry completely.

2. Apply a layer of epoxy filler over all the areas you placed a new layer of epoxy sealer on. The epoxy filler will replace the fiber glass that was destroyed due to the water damage. Let the epoxy filler dry completely.

3. Use a sander to smooth out the epoxy filler. The filler should match the shape of the fiberglass so it completely blends in. No one should be able to tell that you applied epoxy filler to the fiberglass.

4. Wipe away any excess epoxy filler that may be left over on the fiber glass.

References

• Ship 2 Shore Marine: Prevent and Repair Blisters on Fiberglass
• I Paint: Fiberglass Blister Repair & Prevention
• Diseno Art: What is Fiberglass?