Now that I've got my Torchmate plasma table up and running I've obviously been going through a lot of flat plate. I've also been practicing a lot with the TIG, and to get good welds you have to take that black coating off of the plate first. I've always loved my 36 grit sanding disks for shaping and smoothing parts, and they work great to remove the scale when they are new, but they quickly get polished smooth and stop working. My wire wheel doesn't do any better. What are you guys using to get your steel clean? Thanks.