So I took an old hatchet to my new dremel tool 4000 (Christmas present) today and got a pretty nice edge on it. I was thinking about taking to some older beater knives also, is there any problem using a dremel to sharpen? I'm using the grinding bit.
Well a Dremel is going to generate a lot of heat and can get out of control. I would save the Dremel for lawnmower blades and the like really. Hard core grinders (like a Dremel can be) are not a good way to go on knives.
When it comes to sharpening pocket knives I would advise against it. It's not so much a problem of heat generated, but more of angle consistency and pressure. You are not likely to maintain the same angle throughout the entire blade length. The end result would be less than useful. For large machete, khukuri, axes, chisels, etc. it would be perfect.
Like the others have said. Too fast, too much heat. I have tried it in the past myself on some rough edges and was never happy with the results. Took more time to fix it than I "saved" using the Dremel. It's a great too but not for sharpening, at least not in my mind.
I could see using a Dremel on a machete or axe, but that is about it. I used to have a terrible time sharpening machetes, hatchets, and axes until I started using a hand held diamond sharpener (Smith brand I believe). No problem now.
Even at slow speed and with a very steady hand it would be too easy to royally screw up a blade. I know how much fun a new Dremel can be, and how tempting it is to use on everything , but as everyone else has said, I would advise against using it on a knife blade. Axes, and other similar blades would probably be fine though. Enjoy the new Dremel!
I tried this on the false edge on a cheap dagger like folder and the results were not good. Even with steady hands, I could not get any consistency with the grind. I did eventually sharpen the edge, but boy did it look like crap. For the record, the steel was 154CM. If you like the knife I would advise against it, or practice on beaters to get the feel.
I did it once on an Okapi ratchet knife. These are inexpensive knives. I wouldn't recommend it on a knife that costs very much. This knife was literally the dullest knife I've ever seen. It couldn't even really be classified as a knife the way I received it. I think they totally skipped the sharpening stage at the factory. I carefully ground a preliminary bevel on both sides of the blade with a Dremel, then went to work with stones to get an edge. If you decide to give it a try, I would recomend going very slow, using a very light touch, and checking often to make sure there is no heat building up. It is easy to let a Dremel slip and mar your blade. I managed to only have one slip that put a small stripe near the tip
I used a Dremel on a nice Benchmade knife with 154CM steel. I wanted to reshape the blade a little bit, take some of the recurve out of it, and now it no longer holds an edge. I ruined the tempering, so beware! On a side note, can a blade be re-tempered after this bone-headed move, and if so, does anyone know a person/place I can contact for this? Thanks!
you should get a good smiths or dmt course bench diamond hone for this kind of stuff. i like my dremel too but imo its not for sharpening knives. theres a safety issue doing this as well.
I screwed up a lot of blades that way, not advised. You can get a small belt sander, which will be faster if you are doing some major re-profiling, but heat is also a big problem there. If you aren't adjusting the primary bevel on the blade, I would just use a coarse utility stone.
Just in general with a Dremel..no joke, don't use one without safety glasses. They are small, the work you use them on is generally small and it's very easy to discount what 30k RPM will do with shavings or shattered bits. Also almost a matter of practice, you wind up down close to the work with your face to keep an eye on it. I've had one for years and years, I've had cutoff discs shatter and cut my face but had glasses on at least. I simply never use one without glasses on. Also agreed, horrible to sharpen anything with, particularly anything thin bladed. The temper issue, the fact that a small slip will ruin a blade and it's very hard to keep an even grind with one. You could maybe use one for things like a mower blade that don't matter much and are large surfaces but an actual grinder would be far more efficient for that. I did use mine to put a nice lanyard hole in a Mora the other day though ;-).
That is what horrifies me personally. I was working in a shop once where a guy was using a 6" table top grinder incorrectly and that wheel exploded. Needless to say the user was seriously injured, no eye protection at all - he lost the use of his right eye, lost a tooth and was cut up on his face and hands.
If you want to use a power tool to sharpen get a Harbor Freight 1" belt sander. I just checked the site and they are still about $40. Safer and easier to control than a Dremel. I used mine yesterday to sharpen a half dozen kitchen knives to use to prepare Christmas dinner. Took about 10 minutes.
