c-26 fixed keel refinishing question

Post All Keel Topics Here
Post Reply
KeyWest
Posts: 53
Joined: Wed Oct 13, 2010 10:57 am

c-26 fixed keel refinishing question

Post by KeyWest »

We are re-doing the hull and keel on our boat. The lower half of the keel, is covered with fiberglass, and then bondo on the outside, with several layers of paint on top of that. The bondo is a porous pink substance and absorbs water out of the air. Do I need to strip the entire keel? I've opened a large patch and there's no place where there's no gap between the bondo and the fiberglass underneath it. I can always stick a putty knife in the crack, although it's not easy to remove the bondo. What should I do? The edges of the hole are always wet because the bondo seems to be hydrophilic. The bondo layer is a few mm thick.
User avatar
Banshi
Site Admin
Site Admin
Posts: 691
Joined: Wed Jul 04, 2007 10:10 am
Location: Jacksonville, FL
Contact:

Post by Banshi »

Sounds like a no brainer, gotta take it off or you will be doing it again real soon. I'd go back to virgin material what ever that is and do it right this time.
KeyWest
Posts: 53
Joined: Wed Oct 13, 2010 10:57 am

Post by KeyWest »

The bondo IS original. I've searched on the internet and apparently this was a common filler material for keels, and people are still using it! I was very surprised.
User avatar
EmergencyExit
Site Admin
Site Admin
Posts: 2956
Joined: Wed Dec 10, 2003 5:02 pm
Location: Mississippi Gulf Coast

Post by EmergencyExit »

Hi KW,
I'm surprised as well as Bondo isn't too flexible nor too waterproof - I would say get it off if possible and refair the low spots with something like a mixture of West System epoxy and filler strands, then glass over that, paint, etc.

You might find some helpful hints and tips here
http://www.westsystem.com/ss/assets/How ... ishing.pdf
User avatar
Banshi
Site Admin
Site Admin
Posts: 691
Joined: Wed Jul 04, 2007 10:10 am
Location: Jacksonville, FL
Contact:

Post by Banshi »

There are some waterproof bondo type materials. Perhaps this was redone at some time using regular bondo, maybe the result of a hard grouding and not done correctly. Still think it needs to come off and get done right. Any water trapped like that will eventually cause blistering and rotting of the fiberglass.
KeyWest
Posts: 53
Joined: Wed Oct 13, 2010 10:57 am

Post by KeyWest »

It gets worse. I finally got everything off the keel, several pounds worth, then started stripping the delaminating fiberglas sheets off, because I realized they were put on OVER some of the original gelcoat, and therefore not part of the original shape of the boat. There were several inches of extraneous bondo on top of the original gelcoat on the keel changing the shape and the angle of the heel. Underneath that was the delaminating fiberglass that was added on top of the original surface. When I took that off, I realized my keel had no heel. The added fiberglass was like a sock. Underneath, the bottom of the keel heel (the rear corner) was chewed up and missing. Instead, it had been filled with bondo, that WAS STILL WET after almost three years on dry land. It had sand and burnt oil mixed in with the water, all forming a nasty plug inside what had once been the keel heel. As I tried to chisel out the bondo, which was coal black from the absorbed oil, water was dripping down my chisel. So now I don't know what is supposed to be inside the bottom corner of the keel. Is it supposed to be hollow? The guy who did our floor says the bottom of the deep bilge was not as deep as the bottom of the keel. I can't check, because he made the bilge shallower by filling with foam and covering it with fiberglass. This boat had run aground, because we found sand above the keel underneath the floor. Now I know where the hole was.
KeyWest
Posts: 53
Joined: Wed Oct 13, 2010 10:57 am

Post by KeyWest »

Post Reply