How do you guys get your knives shaving sharp?

Leu Custom

Leu Custom

Joined
Jun 2, 2007
Messages
1,354
Just like the topic asks.... What grind belt do you guys grind to/width after heat treatment before you polish or strop or whatever you do. I know how to get a knife shaving sharp, however mentally, i always seem to forget what I did in the process to do so ! (a few hundred blades later even!)

Does an edge need to be polished well and to the eye have no *teeth* in the edge to define sharp or can the edge have what appears to be teeth (from lower grit belts) and still be hair popping sharp.

Thanks!
 
I am no expert but, I sharpen my knives with a stone and then progressively higher grits of sandpaper (up to 2000) on a flat block. Ceramic gets em pretty sharp too but, I'm also interested in hearing how the pros are doing it.
 
I asked Tai Goo once and this is what he said:

Tai Goo said:
The "angle" the "grit" and the "burr".

Angle- determines the degree of sharpness

Grit- determines how smooth or toothy the edge is lengthwise.

Burr- acts as the point of reference for each grit and side. When you raise a burr it is past as sharp as the angle can get... so it tells you when you are done with each grit and each side.

Raise a burr all along one side nice and even, then turn and do the same to the other side. You should be able to "feel" the burr. Then, just walk it down in grits, being sure to keep the burr even and all the way along the full length of the edge. After you reach the desired grit, either use a strop to reduce and align the burr, or use a fine stone.

---------

The angle does not have to be held perfectly as long as you raise a burr and keep the angle fairly even... I usually use a circular motion on the stones and just work it down until I can feel the burr.
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After I used his advice, I got my knife shaving sharp, but it took like 30 minutes.
Richard J uses paper sharpening wheels, and everyone says it's a scary sharp edge.
 
On a newly ground knife I put the initial edge on with a 320 or 400 grit belt, new. I've been playing with the slack belt more, but I keep going back to the 8" wheel, edge down. After I develop a consistent wire edge and push it from one side to the other, I buff it off on a stiff buff with green chrome rouge, also edge down.

When someone asks me to sharpen their knife and it's not totally beat down, I just use the tri-angle sharpmaker. You can feel the difference in the edge that I get, it grabs when it shaves hairs. Many buffed edges will not "feel" sharp but will easily shave hair or filet paper. The hair shaving edge from my spyderco system always has some grab to it, but I find it to be plenty sharp.
 
I'm still experimenting to find what I like.

One of the attempts that impressed me the most was a knife I sharpened with a 'slightly' used 150 belt, edge up and then a couple swipes each side on the strop. it was shaving sharp and had some tooth.

I've found that when an edge is highly polished it is difficult to run it across a plastic shopping bag and actually make it cut and that bothers me, even though it is still shaving sharp. With the 'tooth' from the sharpening method I described it will slice through the plastic with very little effort and pop hairs off your arm.
 
On a knife I'm making that has never been sharpened, I start with a 120 grit belt till I get a burr. Then 220 grit, then 65 micron, then 30 micron. Each time till I get a burr. Then I strop with a leather belt and green rouge compound for a nice mirrored edge. I do all my sharpening on a KMG rotary platen for a nice scary sharp convexed edge.
-John
 
I use an EdgePro Apex sharpener, use one grit till i get a burr, flip blade, use same grit till burr again, flip blade, move up a grit, use till burr, etc till i get up to 800 grit, then i go to 2000 grit polishing paper then strop
 
I hand-sand right down to the edge, getting/removing a burr as others described, then put a small micro-bevel on it with a bench-stone so it's easy to resharpen. Then strop. The problem with this is not cutting yourself when hand-sanding. :eek:
 
How much thickness are you leaving before moving to a stone? Zero edges are very sharp, but also very unsupported and quick to break down. Of course, that's fine for knives that don't see hard use and get sharpened every time after using them.
 
I just started doing it this way, but it works great and I've always been sharpening-challenged prior to trying this. Per the tutorial on this (and other forums), I sharpen edge down on a 1x42 Craftsman with a 220x belt, followed by 400x (if I feel like it, it's not necessary), then finally a leather belt loaded with while compound. I now can get a shaving edge in just a few minutes with pretty good consistency, which I've never really been able to do by hand....at least not without tons of time and messing around.
 
AcridSaint said:
How much thickness are you leaving before moving to a stone? Zero edges are very sharp, but also very unsupported and quick to break down. Of course, that's fine for knives that don't see hard use and get sharpened every time after using them.
Click to expand...

They end up being about 1/64"-1/32" just behind the micro-bevel, depending on how convexed they are. (I need to get a caliper to measure them properly) I realize that wouldn't do well on a chopper or tactical knife. I haven't had any trouble with chipping or dulling on the cutting board or whittling.

How much thickness behind the bevel do you recommend for a fine/general purpose knife? I'm certainly open to suggestions.
 
I also don't measure them - I would guess I'm coming in around 1/32", I just know that they are not so thin that they zero, if I get too thin and it starts cutting, I usually hit it on a belt to bring some meat back. On a chopper or "combat" knife, I try to leave even more thickness since they aren't necessarily meant for fine cutting.
 
For chefs knives I leave a little tooth with a 400X belt. I found the slack belt sharpening is less sharp then flat platen sharpening. I like convex edge only on field knives not on kitchen cutlery. After I create burr on each side I first buff the edge with gray compound, this leaves a great performing tooth and sharpness is more durable. After I always strop with blue or pink compound. I had no luck with the stones as my steel selection is very abrasive resistant. For example to get a burr on a 61-62 HRC D2 knife you have to work on stone sometimes forever. On the contrary with a 400X belt on flat platen it takes a minute or so...
 
I set the edge with a 150 or 220 fresh belt. I grind several passes on one side then flip and repeat. I do this until I am able to raise an even burr along the entire blade on one side (the burr forms on the opposite side of the blade than you are working on). At this point, when help up and examined in the light, you should not be able to see any light reflecting off the edge when viewed head on under a bright light (other than the burr).

Once the burr is raised, I switch to a somewhat dull 400 grit belt and do the same thing until a uniform burr is raised on one side, then the other.

At that point, I sometimes use a very dull 400 with white rouge worked in to draw it out, or I go straight to a sewn cotton buff loaded with white rouge. I make very light passes on each side, just bringing the flat of the edge into contact with the wheel. At this point, I picture that I am trying to straighten and thin out the burr even more. Back and forth with gentle passes on the buff, and then I either finish with a higher angle against the buff to knock off the burr or strop on leather.

This makes a very nice polished push cutting edge. For a toothier edge, I'll stop after 400 (maybe 600) without buffing and finish on a strop.

--nathan
 
It should also be said if you are using your belt grinder to start your cutting edge don't get it hot. I am very particular about this. Why risk destroying your heat treat in the most critical spot. I use a slow rpm wet grinder for roughing, then I go to a coarse diamond stone, a soft arkansas and then 400-800 grit paper. This may take a little longer but I am confident that I am not damaging my heat treat job.
 
I place the edge of the knife against my palm after every pass to see if heat is building. If so, a quick dunk in the bucket and a wipe dry before the next pass. Careful near the tip. It's really easy to dig the tip into the belt when sharpening on the belt. I never pull the tip past 1/2 way across the width of the belt in an attempt to avoid this. If you dig in the tip, it will either thin it out too much, or it will overheat it (purple will happen very quickly on the tip).

--nathan
 
VS grinder is a real + and run it slow

i grind non hand honed edges to a max of 9 micron wet

the 3m micron belts are made of some sort of plastic or cellulose so you can run them wet (bearings don't like it much tho)

my view on honing is a bit limited tho as i make mostly kitchen knives and razors
not hunters / fighters

and there can be a big difference in the way they are best sharpened
 
i use up to a 400 grit belt to work up a burr if i'm putting on a convex edge before buffing with the paper wheel. if i'm putting on a v edge i use the abrasive wheel before going to the buffing wheel. thats all i have used for the past 17+ years with good results.
 
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