My 1983 has an aluminum roof and I had to repair a section under a plastic top box. Anodic corrosion had pockmarked holes all over the front of the aluminum skin.
My solution was to use USeal-Band roof repair tape from Home Depot and Eternabond. The U-Seal was the most affordable way to cover a large area and I used 1" strips of Eternabond to seal the seams between strips and the outer edge of the whole repair area.
If you need to seal individual cracks in the roof, clean with acetone or Eternabond prep. and then fix with Eternabond. Use a metal roller.
If you have to repair the entire roof because it is damaged all over, then there is something called BusKote that is specifically designed for buses and RV's (both vehicles that live outdoors and tend to have sectional roof's).
Jose
