Well, that's what it seems like. I just sent off a bunch of really worn and dull nut files for resharpening, and I have to tell everybody that the results were fantastic!
I'd heard about the practice some years ago, but hadn't acted on the info until just now.
28 files went off to Boggs Tool in Paramount, CA. Some were really dull nut files, some were mill and other style files, etc. 28 files came back, all in better shape than they left. Many were rejected in the process, but still came back pretty sharp. Most of the others came back noticeably sharper than new.
From their Web site:
"We call our file sharpening process LIQUID HONING. Using steam, we relief-grind with abrasive blasting. Abrasives driven by steam pressure remove metal from the back edge of the file teeth until the edge is reformed. If you look at the edge of sharpened teeth under a microscope, you will see that the edge has no serrations. This is called a true honed edge. It is very sharp and it will far outlast regular files. The analogy of using a sharp razor versus a dull razor is appropriate here.
The limitation to liquid honing is that we are not re-fluting the gullets between the teeth. A very fine-tooth file will take only one sharpening. A coarser-tooth file can take several sharpenings. To best use our services, don't overuse your files. We block-test every sharpened file. If it does not pass our inspection, we dye the end in dark red dyekem and reject it. These rejected files will still give you service,
All shapes of files are sharpenable: flat, square, round, half-round and 3-square. All types of files are sharpenable: American Pattern, Milled-Tooth or Vixen, Horse Rasps, Wood Rasps, Swiss Files, Rifflers, Needle Files and Machinists' Files. In addition to sharpening new files, we can sharpen any size, shape or style of used file to a "like new" condition.
This type of honing has been going on since the turn of the last century, and I mean 1900. My grandfather started Keystone File Sharpening in 1932. Though this process has been around for a long time, there's still no better method to be found. Acid and electro-chemical milling has been tried, but it won't improve an edge like liquid honing. We've had some of our customers for thirty to forty years. Let us make you our customer and keep you on the cutting edge.
Our process will give you the sharpest edge possible."
That's quite a good endorsement! So not an "acid-etch" sharpening, but "abrasive blasting"? OK, I've got a fistful of some dull clunker files that should be good candidates. Thanks for the tip!
Oh, and the price.
My total bill was for 66 bucks, including return shipping, for 28 files. Interestingly 13 were marked as rejects, but they were not rejected from treatment. They just didn't respond well enough to pass testing, but they were MUCHO better than before treatment. Charge for them was 20 cents each.
I think Mark Kane had glowing reports a while ago about Boggs file sharpening too.
"liquid honing" sounds futuristic, not like something that's been around for 100 years.
I'll have to round up box of my tosted files. Thanks!
I had a similar experience. My dual-sided tapered files came back FAR sharper than when new, albeit smaller in size. This is a bonus as I now have a bunch of "in-between" sizes. I reach for the sharpened set more often than the newer set.
Anyone know where I can get a diamond file recoated?
I have used then - fantastic on rasps too. You can fit about 8 pounds of files in a Priority cardboard envelope. Just tape up the ends a bunch. You might also try a few hours in muriatic acid - works too.