Speaking of files....OK, we wern't

[Bill White]

If I put what brain I have left in gear, I seem to remember that files could be soaked in some substance that would etch/sharpen the teeth.
Phosphoric acid comes to mind. Am I right? Can ya still buy that stuff? Does it work? Is there an alternate product?
Dang! I really do know how to spell weren't.
Bill :confused:

[David Weaver]

citric acid
phosphoric acid
uric acid (aged, not fresh!)
acetic acid

phosphoric acid is probably the most aggressive of the bunch.

All of them will do a little bit to etch the teeth, but I think the consensus was that the teeth won't be that durable after the fact. That's been my experience using a file on metal after a phosphoric etch, but it may not be a big deal if the files are being used on wood.

Phosphoric acid can be found in concrete etch products. The one I've used is in the paint section at home depot, called phosphor prep and etch, and it's fairly inexpensive. I've used it more for rust removal than for anything else, though.

[steven c newman]

Seems I reall something about White Vinegor? An over-night soak?

[Zach Dillinger]

Seems I reall something about White Vinegor? An over-night soak?

Works well, but only for a little while, then the teeth start to chip with any normal use. At least in my experience. I believe the proper term is "hydrogen embrittlement". George Wilson has had some good posts on this topic.