Restoring auger bits

[Australopithecus scobis]

Greetings, Having fixed the Yankee with a little help from my friends, it's time to work on my latest eBay find, a baker's dozen of Russell Jennings bits. Yum.

Some previous owner cared enough to try to sharpen them. Alas, he seems to have been a botcher. All the larger bits' cutting lips have been refiled from the top. His file left a channel between the lead screws and the spurs. There's an angled land left at the base of the lead screw, which shortens the cutting edge of the lip. This is happening beyond the end of the lead screw's thread. Fortunately the smaller bits were too small for his file. A slip of wet-n-dry folded over a sliver of wood has put them in good shape.

I want to know if a dremel grinder (I don't have one) could get in there and nibble down the base of the lead screw to meet the rest of the lip. There's not room for a file or stone; has to be rotary.

Anybody tried this?

[Jim Behning]

[Australopithecus scobis]

Only working space is between the spurs. Carat and vee point at the trouble spots.

v ( @ ) ^

Run a file from front edge of spur to edge of lead screw; there's a bit of cutting lip that can't be reached. That's the problem. I suspect that over-eager filing in the past may have moved the lip back toward the spur.

[Larry Jaques]

On Wed, 15 Sep 2004 13:03:37 GMT, Jim Behning calmly ranted:

No, but I'd mount the dremel in a vise and hand touch the bit to it under bright lighting, with good face/dust/hand protection.

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[Wood Butcher]

Have you looked at an auger bit file? They're designed for just this application.

(watch the line wrap)

Also, if you're in need of instructions on how to sharpen auger bits, there was an article a year or two ago in FWW, AWW, WWJ, or Wood mag on this. I'm too lazy to go check right now, but if you need it let me know and maybe that'll motivate me to go look.

Art

[Australopithecus scobis]

Yah. It's already highlighted in my new catalog. ;) Next budget-month I'm getting one, and a feather-edge or two, also. However, a file won't work in this case. I did all that was possible with a XX-Slim triangular file and a sandpaper slip. There's no room for a linear object there at the base of the screw. A correctly-shaped cutting lip would be nice, but that's not what I have to work with.

I've reviewed web sites, a couple of library books, and my copy of Leonard Lee's book: I can sharpen a correctly shaped auger bit, no problem. This is a restoration project, however.

Thanks for the suggestion, anyway.

[mike]

I haven't tried this but a 3/16" chain saw grinding wheel in a Dremel tool will work. Even a flat cutoff wheel will work but it may be harder to control. Get yourself a Dremel, very handy tool. For years I thought a Dremel tool was just a hobbiest tool, then I needed one for something and have been using it ever since. mike

[Fdmorrison]

Australopithecus scobis [e-mail]

wrt reducing mis-filed auger bit.

? Why can't you grind a small flat or three-corner file for a safe edge (no teeth) that will skate on top of the cutter lip as it reduces the excess metal beyond the thread of the spur?

There are a great variety of die sinker's files. Might have some candidates for producing the same result. Frank Morrison

[Australopithecus scobis]

Been there, done that. But the lip is encroaching on the spur. Need a 1/4 inch long file! Gotta be rotary. Would work on a new bit, but after having been filed enough times down the flute, the lip creeps around toward the spur. Safe edge files are indeed useful critters, and I wish I'd had one whilst doing the rest of the work on the bits. A shield made of whatever came to hand at the moment sufficed.

Now, thinking about your suggestion, perhaps I could break off a piece of file or hacksaw and epoxy it to a cross-handle. Use it as a saw... Itty-bitty azebiki... Hmm. Heck, I've got a couple of glue-spreaders made of hacksaw and dowel... (5 minutes later) Well, it sorta kinda works.

I also have to figure out something to make with these bits. (Yes, holes; I've got one in me pocket.) These things have been a pain to recondition, but $30 for a full set of Jennings bits is terrific.

Thanks for the advice, all. Vise-mounted dremel, chainsaw stone, face shield, proper files, and kludged filesaw: These bits have a future!