Keel Bottom Paint Peeling

[David Lewis]

I wet stored my O'Day 35 for two consecutive winters after first applying multiple coats of Micron CSC ablative paint. I scub dive and noticed this summer that the paint on the keel in many spots had worn off and I was getting a lot of marine growth, barnacles, mussles, etc. After the boat was hauled I noticed the keel paint was peeling badly but the paint on the rest of the hull is in excellent condition. Does anyone have any ideas on proper preparation for the keel....primers, etc? Could the adhesion be related to electrolysis since the keel is lead and the paint contains copper? Any advice is most appreciated.Thanks,Dave

 

[Tom Ehmke]

bottom painting

Dave,There are a couple of possibilities besides electrolysis (galvanic corrosion, in this case). First, you had the boat in the water for two years and an ablative will slough off. If it seems to be worse on the keel, check how well you faired the keel before you painted it. Also, if the keel were not properly cleaned and prepared, the paint may not have bonded to it as good as it should have.As to galvanic corrosion, if lead keels were a problem with copper-based paints, a lot of us would be having problems like yours. I don't think that there is any HARMFUL current flow from lead to copper or vice versa. If anyone can find lead on a galvanic scale and compare it with copper, that would be definitive. My scale (admittedly not complete) doesn't show lead at all.