My 88 searay was terrible. I wet sanded with 1200 and buffed it then waxed it real good. Its looked great for a year. All the topigraphical fixes in the world wont fill the tiny pin holes that cause the oxidation. Only sanding with wet sand paper seems to work. As long as you do it lightly, you wont have any problems. If you use too low a grit, it can cut right through to the fiberglass