I'v lost track of the thread where someone was asking about fiberglass' absoption of water. The following www address should take you to a com. page where there is a link to an article all about the water - glass situation causing blisters and the treatment of same. I hope this finds you and that it helps.
http://www.wessex-resins.com/home.html
MAKurtis (Emak41-at-excite.com)