Pitted roof from rust under vinyl top repair

barbee6043 said
Phosphoric acid which Ospho is a diluted version. Soak in decent temps several times, scuff with scotch brite, and rince good with plenty of water. Neutralize!!!!!the acid!!!!! Some will say add baking soda. Remember most epoxy primers can react to OSPHO if not neutralized and it can react months LATER!!! I would then apply 3 good coat of a good epoxy primer, level with GOOD filler, I would use a fiberglass reinforced filler, and THEN a good general filler , block, and do a heavy urethane sanding primer, or a polyester primer, block seal and topcoat.. If any imperfection you know it will show in the topcoat!! Or replace that roof!!!!
Vinyl roofs were the worst auto invention...ever!!

The op is not going to like this but, its way less effort to replace the roof section if you can find a good doner car. That roof is so bad , you will see it break out somewhere else anyway after repairing it. We estimated 40-60 hours to fix the original roof on this car. I decided to replace the whole roof from a good doner. Less than 8 hours from cutting the old roof off , replacing it with the doner. Make good measurements and reinforce the structure before proceeding.

Ask me how I know LOL !!

Finished result...