What method is used to repair hydrolysis (blisters) on fiberglass?

Question

How expensive is it and how reliable is the repair?

Answer 1

Take a 9" orbital grinder and heavy grit (i.e. 36) sandpaper and gouge out the blister. Remove all of the damaged (wet) fiberglass. Go back with a 6" orbital and 120 grit and smooth it out.... you're basically creating a dimple where the bump used to be. Build it back up to the original level with fiberglass cloth (not mat) and epoxy resin (not polyester resin). Allow to cure and feather back out with 220 grit. Seal with Interprotect barrier coat.

The average sized blister (~2 - 3") takes about 1/2 hour of yard labor. We charge $65/hour.

Answer 2

Chad: The word blister is the last thing you want to hear. We had some on our Pearson 28'. They can be ground out and gel coat reapplied. Depending on how severe the blistering is. It certainly doesn't mean the vessel is ruined. Water has found a way to seep between the gelcoat and paint. Just make sure you find a competent mechanic for the repair.