Painting over old bottom paint

s calder · Post by **s calder** » Apr 20th, '05, 23:03

My CD 25 was purchased last year. It has ablative bottom paint. 80% of it is in good enough shape to sand and paint over with a couple of new coats of the same thing, but the aft 20%, around the rudder (including the rudder) has "aligatoring" or a network of small cracks in the paint that look like cracks in a dry lake bed. What should I do? Can I just remove what loose paint I can get to flake off, sand, prime with a tie-coat primer and apply more bottom paint? Or does it have to be stripped and started fresh from the gel-coat? By the way, I'm in fresh water. Any input would be helpful. Thank you.

S. Calder

Mark Yashinsky · Post by **Mark Yashinsky** » Apr 22nd, '05, 07:11

is "usually" the result of a too thick coat of paint applied at one time. Do you know what bottom paint is currently on there and what bottom paint you are planning on using? Read the direction on the new paint and see what they say on how to apply over what you currently have. The fine cracks should not affect the efficiency of the current paint, but if you are having a lot of flaking, that will. Remember, the ablative is SUPPOSE to wear off over time, so sometimes there is issues w/ putting a different type of paint of ablative.

s calder · Post by **s calder** » Apr 22nd, '05, 08:38

Thank you Mark for the info. I will check the compatability of the new paint.

Steve Laume · Post by **Steve Laume** » Apr 23rd, '05, 07:04

I am currently scraping the entire bottom of a CD-30. I have similar crazing in previous layers of paint that had been painted over for years. There are many areas where the paint had chipped off down to bare glass and then been painted again. I know I could just scrape off the lose areas and paint away but there will be patches that will chip off and not be protected. There is the uneveness of the hull that just doesn't seem right. I also get to look the hull over very carefully for any areas that could use some care. When I am done I will not have to deal with paint problems for many years to come. It will never be easier for me either as I have the enthusiasm of new ownership. The good thing about the condition of the paint we face is that is does peel off fairly easily with a good sharp chisel with the corners rounded a bit. If you you don't want to do the whole boat, I considered doing it in stages over a couple of years. The rudder seems like a critical area for good smooth water flow. Hey or you could just go ahead and paint it, Steve.

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