Auto body repair & detailing: Rust Under a Vinyl Roof on a Vintage Mustang, vintage mustang, duraglass

Question
I have a 67 Mustang coupe with a vinyl roof. To my horror, when I started removing the trim to replace the vinyl, I discovered rust; so bad that it has perforated the sheet metal in several places. And this is the desert! This car is only a driver and not a rare Mustang so extensive repairs just aren't warranted but I have to do something. I happen to have a roof from a same year Cougar but I know that trying to find enough solid sheet metal to weld in a patch can be a problem. So far it appears that the window openings and the drip rail are solid. My first thought was to kill the rust chemically and then fiberglass the entire roof followed with a new vinyl top. But so far no one here thinks much of that. So what is your take on my problem? Lee in Tucson

Answer
Hey Lee! The rust needs sand blasted , then the holes need filled. The cougar roof will not work. I would seriously consider finding someone who can lead the holes shut, especially if you are going to put back on a vinyl top. It will last a heck of a lot longer than anything else, so the extra expense it totally warranted. If this is not an option, fill the spots with a waterproof filler like duraglass. Then use high quality metal etching primer, then a primer sealer. Then paint the roof. Only paint will finish sealing the roof properly before putting on the vinyl top. Bill