Originally Posted by FrankR
I'm getting conflicting information from this thread. I was treating a hood last night that had an even coating of rust on it. (Almost looked like primer). I sanded it all smooth as much as possible with a scotchbrite before I attempted spraying on a phosphoric acid based rust killer. Rust Cure to be exact. Anyway, the only part that ever blackened as some deep rust pits in a few areas. I was expecting it would turn the whole thing black, but instead it now just looks like wet rust. Its a dull reddish color. What should I do now? Sand it down and treat again?
Yes, I would power wire brush it versus sanding it at this point. Then put another coat of your rust remover on. You will be able to tell while you are putting it on if there is any rust left in the pits. Do it over and over untill you are sure that all the rust or black spots in the pits are gone. Wipe it down with thinner or reducer then do a final sanding with 80 grit, treat with metal prep and put on your epoxy primer. Then coat it with a urethane primer-surfacer.