I am in the process of redoing a drink cooler/minnow box on my boat. It was previously gel coated and then someone at one point painted on the inside with some crappy paint. I'm in the process of sanding the old paint off and filling in all of the gaps and cracks. Can I just recoat it with some restoleum using harder? Should I just regelcoat it? Also, I need to insulate the outside of the box and I do have access to it. Should I just use canned spray foam or would hard pink foam work better and then epoxy/glass the outside of it?