I have a 1980 e-35. when I bought the boat the top side looked in good shape and was shiney. Over the last two years a majority of the topside has gotten a powdery supstance on it. I have been told and I do not believe its oxidation. I have tried to buff it out, sand it, used some chemicals but nothing seems to work. If I take my fingernail and scrape it, the powder stuff will come off and leave the haul looking shiny. Looking for the best way to clean this stuff off.