Yes, you can apply bottom paint over polyethlene (plastic). We recommend applying an ablative bottom paint, preferably ablative such as Cukote.
You should sand the boat with a 60 grit sandpaper, then wash it off with S-80 Cleaner and Dewaxer. After it is cleaned, you should apply 1-2 coats of 1277 bottom paint primer. Let it dry overnight and then apply the Sea Hawk antifouling paint of your choice.
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