I have been having this odd problem when sanding my handles. I used a light coloured wood on the last knife i made (cherry I believe) and while sanding the wood handle, I kept getting super fine metal dust from the tang mixed into the dust. If I didn't notice it right away and clear it, I would essentially rub the grey fine filings into the wood grain leaving it grey looking. Has this every happened to you guys? Am I doing something wrong? Is there a better way? Thanks in advance guys.