I have a steel surface that I'd like to treat to a brushed finish. The steel has been sitting around for a while so it has a fair amount of rust and dirt. The rust comes off quite easily by sanding. However, under the rust there are small pits and cavities with black dirt in them and these are very hard to sand away.
Any suggestions on how I could remove the dirt? The pits are so tiny that I don't think they'd be too visible if I could just get the telltale black dirt out of them. I'm willing to consider even drastic measures. Or do I have to just sand deeper?