Did you follow the direction on the bottle ? Most of them will say not to use on clean bare metal so if you spray something rusty and get it on the clean metal it can flash rust.
I did review what was available before applying, but Nothing on the bottle or website about avoiding bare metal. I'm guessing I probably just shouldn't have put it on. Live and learn. I'll take the advice of seeing if it'll brush off and maybe grab some other stuff to hit the pitted spots.
