Hi folks! Thanks for all the great responses about keeping files
clean. I went ahead and tried the experiment of placing the file in
a ferric chloride solution. It was the exact same stuff I use for
etching copper. I put the file in the ferric, right in the bottle,
made it a point to swirl it soundly every couple of minutes, and
pulled it out after about 1/2 hour. The file looked terrible and I
thought I’d ruined it. However, I went ahead and neutralized it in a
soda solution, washed it soundly under running water, and ran a
brass brush all over it, It came out great!! All clean and sharp and
no indication that it had ever been used on copper at all. I gave it
a quick dip in kerosene for protection and all appears well in the
file world. At least as far as I can see so far. Thanks for all the
tips. I figured I’d better provide a follow-up. The ferric chloride
worked very well.
Mike