In the refurbishing of my CD 27 hull number 8, 1977 , I began removing 30 plus years of paint down to gel coat. I found a few blisters which have been opened and repaired except for a recurring problem at the heel (forward of the shoe of the rudder post) of the keel.
It appears on my boat and several other CD's in the yard that this is a vulnerable area for water and would very much appreciate any experience other CD owners may have on how to fix the problem. As mentioned, I carefully opened the area, dried it out and patched and began barrier coating. On my third coat, a tiny bubble again appeared followed by a small dip of water which was less than an eye-dropper amount.
So any suggestions, experience, remedy?
Many thanks
weeping keel - CD27
Moderator: Jim Walsh
-
Matt Cawthorne
- Posts: 355
- Joined: Mar 2nd, '05, 17:33
- Location: CD 36, 1982
Hull # 79
One possible procedure.
I could use a little more information, but it sounds like a condition that I had on my CD-36 when I purchased it. The deep, narrow portion of the back of the keel is close to impossible to gain access to when building a boat. Building a laminate in there is a real challenge. I can't be certain, but from what I can tell, the semi-cylinder of glass that forms the pocket into which the rudder nests, is made in advance of the hull on a separate mold. At some point, that is placed in the mold, gelcoat is sprayed in, a generous blob of chopped fiber and resin are loaded into the bottom-aft portion of the keel and then layup begins. The chopped fiber/resin combination can have lots of air pockets (some of them connected) and the interface between the pre-manufactued semi-cylinder, with the attendant re-entrant angle can be tough to fill. I had weeping along this line. My solution was to drill in and find out what was back there. When I drilled the top it weeped a bit, but when the bottom was drilled, a geyser erupted for several seconds. I filled a syringe with acetone and flushed out the cavity. With the aid of a vacuum pump, the cavity was dried. Using a syringe, epoxy was pumped into the bottom hole until it exited the top. The bottom hole was plugged until the epoxy hardened. The entire surface was ground down a bit and allowed to dry for several months. Two layers of 181 glass cloth were applied with epoxy and then the surface was faired in and barrier coated. No problems in the 14 or 15 years since.