I believe that the entire roof may have pinholes so I'm coating the whole thing.
It's a 1994 Four Winds 5000 which is 29 feet. I have ripped out most of the wood and foam in the cab-over and I plan on rebuilding that when I can. First I'm just trying to seal it and stop leaks. Later I'll reinstall the foam and put in new wood framing as needed. It has some aluminum framing.
I plan on cleaning the aluminum roof with TSP (tri-sodium phosphate) before I apply the elasomeric coating... unless anyone here thinks I should prep the roof differently