Re: painting aluminum boat?
If the paint is holding well, you should be O.K. just spot-priming any bare metal with zinc oxide self etching primer and scuff sanding the existing paint for adhesion. I read a lot of posts and it seems to me most people like one component paints like Petit Easypoxy for aluminum boats. I used it on the bottom of my hull and was very happy with the result. Are you planning on spraying or using the roll-n-tip method?
Good luck,
Jim