Is Gel coat over old polyurethane paint even remotely possible.

I probably know the answer to this, but I thought I'd ask some experts. About six years ago, I completely re-shot my sailboat with Petit Perfection polyurethane paint. I live in Texas, and the sun here is brutal. the hull still looks brand new, but the topsides have already taken quite a beating. I am very disappointed in this boat finish. I have painted boats with cheap Dupont automotive paints that actually held up to the sun better than this stuff. I am now wishing I had put the extra work in and gone with gel-coat. so.......

Any possibility that I can shoot new gel coat over this old paint if properly prepped, and scuffed? or am I stuck regrinding the entire thing back down to old glass/gelcoat once again? Any help appreciated.

 

Welcome to the forum.

Sorry, you have to grind off the paint and get back to good mat, reprep and . . . you know the rest.

 

What's to stop you re-painting the topsides ? If the paint is just faded or chalked, rather than lifting off, it should not be a huge job, but trying to go back to gel coat is nigh on impossible. In any case, the gelcoat must have been weathered for you to paint it, who's to say it wouldn't be looking weathered again by now ?

 

Use a high quality two part urethane paint and you will not need or want gel coat.

 

Im confused, you say that the hull still looks brand new but the topsides have taken a beating, which is it? The topsides are the hull sides. Perhaps you are reffering to the deck molding.
No, you cannot gelcoat over paint, your best bet is to sand it down and re shoot it with a compatable paint, you dont need to sand it down to the gelcoat if its still sound other than faded.

 

I concur with messabout. Compared to 2C polyurethane, gel coat is in fact a mechanically and chemically inferior product.