Etching machinist files

I'm looking for an appropriate acid solution such as muriatic acid ⇦ on eBay or Amazon [affil link] to etch laminate and machinist files as to sharpen them after a long use by removing some of the metal on the teeth so as to "sharpen" them anew.

I really doubt if it can be done. My guess is that it will preferentially attack the point of the tooth several times more than the root of the tooth. Solution flow and what I will wrongly call internal stress are my thoughts on why.

I think you're right, Jim, and only hesitated saying so until somebody else had a chance. Tensilely stressed areas are cathodic to the balance of the item and will be attacked first. I don't know for sure, but I would hazard a guess that the points of the teeth would be tensilely stressed.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

In answer to your question, there is a company that uses a "reverse electrolysis" process to re-sharpen files.
I used to pick up auto body files, send them out; when they were sent back, I delivered them. Files are called " cheese graters". Also vixen files and horse rasps. I would guess most any metal file could rejuvenated. Thanks, Paul