I keep getting black gunk off of my pen bushings and it is staining my wood. It is happening with all my bushings, even the ones that are supposed to be hardened steel. When I use EEE and even Renaissance Wax it gets real messy. I can put a clean rag up against a bushing and it always comes off black. I can see this the first time or two but I have busuhing I have made over 20 pens with and it still happens. Yesterday I was making a pen out of holly and when I switched from regular 400 sandpaper to micro mesh the holly turned black on me. I had to go back and sand from 150 again to get it out and had to just stop at the 400 level. I'm not sure if its the sandpaper, bushings, or combo of both casing the mess but it is making it hard to keep the grains looking nice. Any tips would be much appreciated.