Sharpening a File Using Vinegar

[Bruce Wrenn]

I have a 50 year old (bought it new) 12" Mill Bastard file that finally had to be sharpened. I used a bath of white vinegar to soak file for 24 hours. Rinsed file off, dried using paper towels and heating with torch. Sprayed with WD-40 to prevent rusting. Cuts like new now!

[Jebediah Eckert]

Good tip, I’m trying that tomorrow.

[Tom M King]

Ones that aren't worth fooling with are little ones that you use the edges of, like triangular saw files. The teeth get worn down on the corners too much to have enough left to sharpen. You can take off too much too, and the teeth will be too irregular to cut smoothly, so it's not as easy as it sounds.

[Brian Tymchak]

Ok, I'll bite. How does a vinegar bath sharpen a file?

[Bruce Wrenn]

Ok, I'll bite. How does a vinegar bath sharpen a file?

Google "Using Acid to Sharpen a File."

[Chris Fournier]

In my experience this technique will bring back an "almost good" file but it won't restore dead ones. The cutting edges need to be good enough that a small amount of material removal sharpens things up. I use muriatic acid and I do so outside of my shop, you don't want the acid fumes affecting your cast iron and tool surfaces.

[Tom M King]

When you send them off to be sharpened, they are acid sharpened. Rust remover will do it too. I find they're never as good as new though, so quit bothering to try.

[Joe Rogers]

Boggs Tools does not use acid to the best of my knowledge.
Joe

[Tom M King]

Yes, looks like I might have been wrong about that. The only two places I know of that sharpen files, are Boggs, and Save Edge.

It's been many years since I sent any off. I don't know where I got it from that they used acid. Found this:
https://boggstool.com/file-division

edited to add: My memory must be worse than I thought. I went to the SaveEdge site, and didn't find anything about sharpening. Might have been someone else. I think it's been close to 30 years since I sent files, and horseshoeing rasps off to be sharpened. I do remember thinking that they didn't come back as good as new, so maybe things have changed.

[Dave Cav]

I sent a pile of files from school to Boggs and was pretty happy with both the results and the price. I've sharpened my own files using battery acid, citric acid and muratic acid; all will work reasonably well but you really have to keep an eye on them and wear your PPE.