[cfelton]

Welcome to the site! Kracker Jack is probably right. I'd drill small holes at various locations and see what the wood looks like that comes out. Check around the bottom drain, and any spot where the glass has a hole or has been drilled to mount anything. If its only one small spot, I'd remove the glass and expose the wet wood to let it dry. Remove as much of the decayed wood as possible. You can inject GITROT into the remainder and fill it back in with tigerhair or just cut up some matt and glass it back in. Be sure to grind or sand and wipe clean with acetone before appling fiberglass. Good Luck!