There are a couple of issues with epoxy and paint that have to be observed. Not all oil based paints are compatible with epoxy, and paint manufacturer's are often hesitant to tell you if their paint will work for sure. Most of the water-borne paints are OK. You can do a "scratch test" to verify compatibility: somewhere paint a 4" x 4" rectangle, let it cure a few days, and then use a metal ruler and x-acto knife to score the paint in a grid pattern every 1/4". Apply a piece of cellophane tape to the grid pattern, burnish it down with your thumbnail and then rip it off. If any of the paint comes off in 1/4" pieces then the paint is not compatible. Another way is to paint the entire boat, launch it after two weeks, and note if the paint comes off in large, 2' square sections. Also, make sure the body filler you use is waterproof. Bondo brand auto body filler is not. It works on cars because you paint over it, and cars are not submerged in water (or, if they are, you have worse problems than your body repair work!) A good alternative to Bondo is to use epoxy mixed with collodial silica (or "fumed silica") to a paste the consistency of Bondo. Epoxy has much more water resistance than Bondo brand body filler. On Thu, Apr 30, 2009 at 8:08 AM, Chris Smith <chris.r.smith@gmail.com>wrote:
Hello all, I've been following this thread with great interest, as I'm involved in the same project. My M15, though, is in a bit rougher shape than I expect most others are. I rescued it from the salvage yard, repaired some gaping holes and am getting quite near to the paint issue. As I'm in Minnesota, I'll be exclusively freshwater sailing, so I'll be following your collective advice on paint.
But, with the numerous dings, scrapes, scratches, barnacles and other places where the hull has been rubbed down to (or through) bare fiberglass, my question is this: can I do a skim coat of epoxy over the entire hull before painting to even out all these imperfections?
There are still some rough patches in the hull that need glassing, and the front of the keel needs to be built back up (I plan on using bondo covered with fiberglass), but once those are done, there will still be the issue of minor imperfections that can't be sanded out.
Thanks to all for your collective wisdom!
Chris M15 Persephone
On Wed, Apr 29, 2009 at 5:49 PM, John and DesAnne Hippe <jdhippe@gmail.com>wrote:
Hello All,
Thanks for everyone's input. After consideration I have decided to follow Gary's advice and go with VC 17. It is a thin antifouling paint recommended for fresh water. Because it is formulated with teflon it should be slippery. It is also said to produce a "hard, super-smooth racing finish." Just the thing for an M-15...
I am almost done removing the old bottom paint. I began with 80 grit on my random orbital then switched to 100 grit on the random orbital and am finishing with 100 grit by hand to get into the corners of the lapstrakes and the other areas that my random orbital wouldn't go. I love the looks of lapstrake but it sure is a pain to sand. It is a joy, however, to see the bottom beginning to look so much better -- and smoother. No more old, lumpy, flaky bottom paint.
If I had it to do again I would have begun with a scraper. I originally tried this with a bad scraper and then abandoned it. Later I found a better scraper (a pull type) that worked very well.
In addition the the cracks that I mentioned in previous posts, I have found a couple of spots where the gel coat has chipped off. So, before painting I will be repairing these.
John M-15 Jester _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats
Remember, there is no privacy on the Internet!
-- Chris _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats
Remember, there is no privacy on the Internet!