blistering

[NALANI13]

we just removed the cushions in our cockpit and discovered that the fiberglass was blistering behind them. it isn't anywhere else, just there. What is the best way to deal with it?

[EO32]

Don Casey's Hull and Deck repair book shows how to fix blisters. It looks pretty easy if you're handy with tools.

He cautions that the blisters are under pressure and the water has turned to acid, so be careful when you pop them. Wear safety glasses.

Basically you grind them down and gelcoat over them.

[TrueBlue]

I would first check to determine if the blisters are osmotic. One way to do this is if when pierced with a sharp knife, a darkish, noxious smelling fluid oozes out from beneath the bubble. Otherwise, moisture may have gotten behind the gelcoat, creating delamination from the fiberglass layer.

Either way, the affected gelcoat needs to be ground down to bare fiberglass, or deeper if delaminated. Then repair the area by filling/fairing with the appropriate compound(s).

[NALANI13]

there are a lot of areas where the bubbles have opened on an edge so hopefully they aren't osmotic. But there are larger bubbles that may be. I will have to get his book. I am really worried about leaking. thanks for your help

[sailingdog]

Wear goggles or other eye protection, since the fluid in osmotic blisters is generally under pressure and can spray...and is rather caustic.

Are you sure they are gelcoat blisters? Paint will also blister in a similar manner.... and if the deck was Awlgripped, it might be paint blistering.