I own a 1975 CD 25 with O/b well that I like very much. I recently noticed small blisters approx 1/8" in diameter , in a group just abovethe waterline mid ship. i punctured a couple of them and no water came out. What has happened here and what can i do about it. I like the boat VERY much , but dont want to put good money after bad. also the boat has been out of the water & covered for 2 yrs in LI , NY.
SSPIN63636@aol.com
Hull Blistering
Moderator: Jim Walsh
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Ron
Re: Hull Blistering
Mike,
Since your boat has been out of the water for a while it is possible that your problem is occurring from the inside out. Blistering can happen on boats with inadequate ventilation and a high interior moisture level. If this is the case then that might explain the location of the blisters. You might want to check your moisture level of the hull all over and make sure the interior is properly ventilated. Then I would get the hull as dry as possible before making repairs. A good source of info is West System booklet "Gelcoat Blisters - Diagnosis, Repair and Prevention". Good luck.
ronrussell@mindspring.com
Since your boat has been out of the water for a while it is possible that your problem is occurring from the inside out. Blistering can happen on boats with inadequate ventilation and a high interior moisture level. If this is the case then that might explain the location of the blisters. You might want to check your moisture level of the hull all over and make sure the interior is properly ventilated. Then I would get the hull as dry as possible before making repairs. A good source of info is West System booklet "Gelcoat Blisters - Diagnosis, Repair and Prevention". Good luck.
ronrussell@mindspring.com
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Dana
Re: Hull Blistering
___________________________________________________________________Mike wrote: I own a 1975 CD 25 with O/b well that I like very much. I recently noticed small blisters approx 1/8" in diameter , in a group just abovethe waterline mid ship. i punctured a couple of them and no water came out. What has happened here and what can i do about it. I like the boat VERY much , but dont want to put good money after bad. also the boat has been out of the water & covered for 2 yrs in LI , NY.
CD blisters commonly occur at the mid ship location you describe as well as along the forward upper section of the boat. Not all blisters need to be "wet". I had found a few above the waterline which were just air voids. Well, I should clarify this a bit.....It had a bit of dry fiberglass mat which did not appear to have ever been saturated with resin. I had just repaired them.
The other type in this area had wet fiberglass mat behind the gel. These areas "wick up" mositure from the hull below. Again, I just repaired them. This was about 10 years ago. Because the repairs were in an exposed area I took the opportunity to raised the entire waterline and relevel it to the actual boat float angle. That really helped the fouling around the boot top which was occuring and covered the repairs.
My repair proceed was straight foward. There are a basic three layers going into the hull surface.....first the thin gel, the chopped sprayed mat/resin layer and then the laminate fiberglass lay up. Cut away the gel over the blister to about the size of a quarter I think for what you describe. Grind back the gel around the edges until wet, losse dry or discolored mat is gone. Don't go thru that laminate. Clean out the surface with acetone. Paint a thin layer of West 105 epoxy and hardner (comes in small packs of both) onto the surface. Fill the area with Interlux two part epoxy filler (Parts A and B) if you want something close to a light cream color. Some folks like the Red Hand two part filler but it is red.
For above the waterline this is probably ok, for below the waterline I take off a section of the surrounding bottom paint and coat the general surrounding area over the former blisters with West 105.
darenius@aol.com