Some years ago I stripped a petrol tank and left the metal bare - result, lots and lots of tiny spots of rust. I rubbed these down and sprayed a single coat of undercoat on it and the spots reappeared through that. Doesn't seem to have become much worse in 5 years, just lots of bumps and little rust spots through the paint
I'm planning now to strip and repaint this for use on a project - does anyone have experience of how I should treat the metal / anything I can paint it with to stop these coming through again and to let me kave a nice smooth finish?
thanks
Andy