You can find it in gel form, or spray on form. Put on, wait for paint to bubble up, wipe/scrape off. Hell of alot less work then sand paper.
If you don't feel comfortable with chemicals, get some automotive stripping sandpaper. Its 40grit, and will rip the paint right of your frame. Makes sure you don't contact the metal too though, because itwill scratch it up.
nitromors could work it will strip paint of anything and won't leave your frame scratched from sandpaper
doesnt wet sanding help with scratches? when me and me and my dad were doing his street bike frame...we snaded it then wet sanded with a finer sandpaper and it made it super smooth
NOOOOOO don't sand it. It leaves marks and makes it rust faster. go to wal-mart and pick up a heavy dutie chemical paint stripper. take a brush and paint it on think. leave it over night and when you come back in the morning the paint should just fall off giving you that natural raw look! If you sand or use a wire brush it makes scratch marks and doesn't look natural.
go to home depot and get this acid stuff forget what it is called bout my friend used it to get oil off his drive way( bit of over kill) and if you put it on paint it will just melt it straight off