- Joined
- Feb 1, 2015
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- 9,574
I have sharpened files with muriatic (hydrochloric) acid. It basically works by removing metal from the surface at a more or less uniform rate so the radius at the edge of the worn file reduces to zero. It doesn't correct gouges in the file though. and there can be a slight uneveness to the new surface. I expect that electrolytic sharpening would be much the same with the exception that there is no need to replenish the spent acid.