I have a friend which bought a Jet 6 inch planer for a job. He used it very little and it set under a Window AC unit in his shop. Well the bed and side piece rusted after a couple of years and he gave it to me because he did not want to deal with it. I covered it with my home made penetrating oil so it could soak into the rust. It has been soaking for about 6 months. I think I need to deal with it. What grit sand paper should I use? Should I start with 220 or coarser? There are no rust pits.