I can’t be the only person with this problem. I got a U.S. Coast Guard Capacity Information plate, made out of aluminum screwed into back of boat, well oxidized, very hard to read, can barely read it now. My question is How do you clean these plates without taking all the paint off, and making this plate worthless?. I had other plates that I tried cleaning with Dawn soap, had good luck with some, not so on others. Thanks, Gene.