I searched for an hour for sacrificial anodes for aluminum roofing such as is on RV's and I could not find any such application. Do you have any information for something that would work for RV's or have you tried it?
Sacrificial anodes will prevent or slow down galvanic corrosion. In order to this the anodes need to be in contact with the electrolyte. This is not possible on the roof of a Hi-Lo because the corrosion is starting on the underside of the roof. Moreover the electrolyte appears to be a bit of moisture. This is not enough to ensure electrical continuity with a localized anode.