I have a 95 carver 355motoryacht and the radar arch and some other parts aluinum the paint has flaked off ,I want to repaint ,but I'm worried about the different color white because off the sunfade of other parts of the boat and the aluminum prep and bonding,any suggestions?
You want to compound the gelcoat of the area near the arch to get as close to the true gelcoat color as possible. A good paint supply place can color match the paint you would be using on the arch to the existing color of your gelcoat. As for the arch, the best thing is to strip it down to bare aluminum, put a good primer (usually zinc oxide) and repaint. There are even additives you can add to make the new paint less shiny if you want it to look closer to the gelcoat. Or have it powdercoated (but this is a pricey option and requires removal of the arch.
