Just did all mine, 1-10 hydrochloric solution for 2 hrs. Like new and super sharp.

Thanks for the tip. I will print it and place in the tool chest with the checkering tools.

I’ve thrown a lot in the bin over the years but after a discussion on here about sharpening files with acid I gave it a go. I like Dembart cutters a lot, but they don’t last long.

Have you tried it on files?

How about rasps?

Roger

Craigster no, Yuma yes.

....from that, I assume it was a success?

Roger

Sorry, yes you can do rasps, but I haven’t.

Just wondering was this process invented or discovered?

quote:

Originally posted by richj:
Just wondering was this process invented or discovered?

I have sharpened files this way for 40 yrs. An old guy I worked with told me about it about "74"??

Acid etching is not really sharpening..it simply roughens the surface...but.. will get you a little extra life out of an old file. Sharpening is done with carbide blasting..actually removes metal from the back of the tooth.

Many firms do this, I happen to like Boogs Tools, 800 543 5244. They are n CA.

They come back better than new..Really! and at a surprisingly low cost. I have had some old Nicholson 49's & 50's done four or five times

I wonder if a place like Boggs could resharpen DemBart checkering cutters. They do tiny needle files and such,,

Maybe if you clamped them up in a multiple/gang set-up so they'd be easy to handle??

I've owned a European manufactured "hydro hone" water-blasting setup for 7-8 years now. It's brilliant for sharpening files, rasps, even end mills and some other cutting tools. It also can be used to leave a vastly superior surface finish on blasted parts than traditional dry-media blasting. Nothing new about it's use, just not many people seem to cotton on to it.

Prior to that I was using the acid bath technique on files and rasps. No comparison in the results I've obtained as far as sharpness goes, the hydro honed edges last longer and cut better, there is no fume and waste problems, and after-rusting is much easier to deal with when hydro honing. Good files are getting really hard to come by and my setup has paid for itself between sharpening and hydro-blasting parts. With the right media of appropriate mesh size, it's a versatile system, and without most of the horrid mess and contamination of a dry blasting setup.

The quality of DemBart cutters took a huge dive some years back IMO. For several years they got so bad that they were not only unable to cut freely when new, but the Vee facets were nothing like straight. Checkering cut with an ogive is ugly. I ditched them and now make my own, and have much improved cutter life to boot.

However, I had a stash of DB cutters from the 80's which were good, but eventually ran out of them. I resharpened them several times with the hyrdo-hone technique when I first got it. Trickier than needle files, but it worked if the correct mesh size was used. If checkering cutter quality was good, I doubt it would be worth hydro honing them unless you owned the setup.

If the cutting edge has gone too far by continued use after the file dulled, the results will obviously be compromised. Sometimes this is just one side of a file however, or one area of the cutting surface. A lot of folk are really hard on files and keep using them once dulled. With acid sharpening, my experience is forget it with the files with a damaged tooth form rather than if they are just dull. With the hydro honing technique, they come back a little better and can often be serviceable if not brilliant. The most important thing is to stop when they start dulling off, and then hydro hone.