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windrift2
6th July 2014, 09:54 AM
In the process of bringing back my families 69 17 ft Carver runabout.Boat is in great shape.Lapped plywood.As a kid I remember sanding and repainting it but what about bottopm paint.I,m a retired carpenter and dare I say sailor for 45 yrs,so I know about bottom painting,but whats on this is not bottom paint.Some type of bronze color paint.Boat has always been trailererd and stored inside.Any help with paint and can you use 3M 5200 on bottom .Thanks Will be my winter project

PAR
9th July 2014, 02:52 PM
Bottom paint is an anti fouling coating, used on craft moored or berthed for more then a few days, typically months at a time, but any boat that will spend more then a weekend in the water. If you have a trailer borne boat, you don't need anti fouling (bottom) paint, as it's not in the water long enough to need it's properties.

3M-5200 can be used under the LWL, but it has to remain under pressure for the full length of a cure (a week or more). This is typical of all the polyurethanes, because of the way they cure. If applied topically and immersed for extended periods, it'll just peel off in long, rubbery strings. Polysulfide (like 3M-101) is the usual choice below the LWL on wooden boats. This is the goo used on production lapstrakes, such as Chris Craft, Thompson, Lyman, etc. This said, if you use polyurethane (like 3M-5200) inside the laps, when doing repairs and fasten them down tight, it'll work fine. It just doesn't work well if it's topical or an unsupported (read crushed) bead.