Sharpening Files

You can send files out to be re-sharpened. Lore also says you can sharpen them up yourself by soaking them in battery acid or vinegar. October 28, 2005

I have a large number of old files from my father-in-law. Some of them are of a size and shape that I find would be useful in my work. However, after a number of years of abuse in toolboxes, drawers and bench tops, they don’t work as well as new ones. The cost to replace would be significant. Is there a company that would refurbish and sharpen them?

Forum Responses
(Furniture Making Forum)
From contributor A:
I spent a few years working for a large laminate display manufacturer and we sent our laminate files out to be acid etched about three times each before throwing them away.
They weren’t quite as sharp as a new one but they were sharp. If the files have a lot of rust then they are probably a loss. As far as who to call about acid etching files, I would start by calling a large sharpening service.

From contributor B:
I would recommend Boggs Tool.

From contributor C:
Weyger’s book on blacksmithing talks about using used battery acid (free) to sharpen files. I’ve heard about that for years from folks but never tried it personally.

From the original questioner:
None of the files I am considering are rusted, just dull. I will look into getting a quote from Boggs. I have heard of some company in Ohio but I think I will avoid sulfuric acid myself.

From contributor D:
I just had some files sharpened by Boggs, and I recommend them. The price was very reasonable, $1-3 a piece, and I was impressed with the results. Including shipping both ways, I ended up paying a total of about $2 per file, which was a lot cheaper than buying new ones.

From contributor E:
An old gunsmith told me he sharpened files by immersing them in pickling vinegar. I have not tried this but if you have a lot of files it might be worth a try. The amount of time the file is left immersed is a matter of trial and error. Also, I suspect the condition of some files may prevent the use of this process to revive them.

From contributor F:
I just want to second the recommendation of Boggs Tool - they will even sharpen a brand new Nicholson 49 or 50 rasp, before shipping it to you, and when they do so, it's noticeably sharper than a stock one. I've used them a couple of times. The service is not fast, but they offer incredible results.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor A:

I have bought a lot of old worn out files and I sharpen them myself with muratic acid. All acid is dangerous so I'm not recommending anyone do this but I scrub the oil off and soak them in muratic acid. It doesn't take long, maybe 15-20 minutes at the very most. You have to stay with them and watch. The acid eats down past the rolled over or dulled edges and brings the file back to life.