I have 1998 F150 that paint on roof cracked and flaked off from heat in Arizona. Nobody wants to repair due to rust that formed and I would like to know if RE is appropriate to use after removing loose rust? Can it then be primed and painted with automotive finishes? Don’t want to spend $1500 – $2000 to have roof skin replaced as truck has over 124,000 miles on it. Same token don’t want to drive down road holding an umbrella during rain storm because roof rusted through.