Sharpening Knives

[Jeffrey]

I found this on Grizzly Tools: http://www.grizzly.com/products/Combo-2-Belt-Sander-6-Disc-Sander/H7761
I would appreciate and views on if this would be a good way to sharpen knives.
I have seen people use non powered systems before and to be honest I really do not relish sitting for hours grinding away on a knife blade like that.

[edge9001]

grinding away for hours, not so. I've sat for an hours sharpening a blade. if you use a proper very course stone, after running the blade across a sanding belt or grinder once. and then progress through the course to the fine and then finer still stones, It doesn't take hours to sharpen a blade. BUT take one of these belt grinders and use it carefully it should work well. I prefer a hands on aproach instead of power tools for sharpening.

[BIGGUNDOCTOR]

I wouldn't get it to sharpen a knife, too fast which can burn the temper out of a blade. Motorized sharpeners are generally slow turning to keep the heat down.

With proper stones, and technique, it does not take long to sharpen a knife.

[NRunals]

I agree, just take the time to learn proper sharpening methods with stones. It isn't that much slower when you get good at it, you have more control (in my experience at least), and you can sharpen a knife anywhere you have water and your stones.

[bigfootnampa]

I consider myself somewhat of an expert on sharpening edge tools (knives included). I use lots of them and have, over time, used most all sharpening systems from completely hand powered to totally motorized. I use a similar machine often and I like it quite a lot! I consider it overkill for a knife that already has a quality bevel and simply needs a rehoning. Using it for that sort of purpose will result in a much shortened useful life for your blades. On the other hand, I would be likely to use it on most new knives (as few come with truly optimal bevel grinds). I'd also be likely to use it on most larger blades that have had abuse which left them with nicks or badly rounded edges. It does require some skill to use effectively... so it is a poor substitute for practice and patience. In the hands of an expert it can be nearly magical though! I have sometimes (often) put edges that will shave hair on blades with only a grinder like this and a buffing disc charged with white diamond. If you want an optimal edge though a few other steps will improve the edges. You can easily overheat a blade on it... though with care and skill you will rarely do so. In summary I will say that most pro knife guys will get great results with it... I would NOT really recommend it for those who do not at least aspire to such levels of skill though.

If you own good quality knives which have very hard steel blades, you may want some good diamond stones. They will cut the hardest steel and get pretty good edges too. Some of the modern blades are of (IMO) steel that has been hardened to extreme levels and a file won't touch them and even a good coarse abrasive stone is VERY slow going. These blades are no match for diamonds though. IMHO they are hardly worthy of the time spent sharpening them though... they are usually sharpened to quite blunt bevels (to make their edges last and last... though they are never very good). This blunt sharpening method also helps to prevent chipping of the blade edges (which these overly hard edges are very prone to). It also dooms them to a level of sharpness that I personally find less than acceptable... even for backyard utility work.

[ThomasPowers]

There is a big difference in just touching up a properly shaped blade that's just got a touch dull and re-setting the bevel to a better angle and then sharpening the result!

I consider "touching up" to be easily done with stones if the alloy/heat treat doesn't require diamond OTOH I would much prefer power if I have to waste much material to get a decent angle!

[Dragons lair]

I am not a blade maker. Just have to ask what happened to the old razor strop.
Have an old 70+ farrier knife maker friend. 4 strokes with an arkansaw stone
6 with a strop. Drop a horsehair and cut it in half. I have soft stones, hard stones diamond stones still can't out do him.
Ken. PS I grew up with barbers who didn't use throw away razors.

[edge9001]

Just have to ask what happened to the old razor strop.

I still use them. My last haul came from a guy whos grand dad was a blade smith and made folders. in the trunk fullof stuff I got 5 strops in great condition, a small tub full of brass folder parts, 7 or 8 scythe blades, as many or more saw blades a champion blower, and about 20 lbs of lead with ladle.

so i stilluse the strop, both on the blades and the kids. hehe grab the strop and the kids jump in line, never even need to use it on them, just threaten to.

best thing ive found is when you get the knife as sharp as you can, run it up and down the strop a few times and it will shave you quite easily.

[cracker72]

That machine looks useful for getting edges true when tool making, but I agree, hand sharpening is the way to go. It's a skill that takes time to learn.
I use Japanese water stones 1000, 7000 and finish with my leather belt(strop). If it will slice a sheet of A4 like it's not there then it's good enough for me.