Buuuuuuurrrrrr!!!!

After a fine stone 15000+ I take a kitchen towel and stroke the edge at a 90 deg angle to the hanging towel a few times back and forth. This will clean up the edge. After I give a few very light strokes on my finest stone at the primary edge angle.
 
There are exceptions and qualifications for every technique. When I talk about a 45-degree deburring angle that is the most extreme case for stubborn burrs. Hard and fine-grained alloys often have a lessor tendency to form burrs than soft alloys. Some of the worst stuff I have seen is cheap and soft high chrome stainless. The 45-degree deburr is particularly necessary if you have removed a lot of material from a troublesome alloy. In that case a microbevel at 25 degrees or so just may not work. If it doesn't work do the 45 degree deburr and then a light sharpening. Often you can get the result that you need by careful micro beveling.

For example tonight I sharpened 50 kitchen knives prior to going down to the local soup kitchen. I'm tired and I don't want to spend more than a couple minutes per knife. I am willing to compromise the edge quality for speed. I hit them all with fresh 220 grit on my belt sander. I try and do a light deburring with the same belt. Then I move on to a worn 400 grit belt. I polish and slightly convex my bevel and deburr as best I can. I set the edge using the edges of my Sharpmaker medium rods at 15 degrees per side. I finish with a very light microbevel at 20 degrees on the flats. I really run this on an assembly line style of processing. I need to get up at 5:15 tomorrow to haul food down to the kitchen. If I haven't sharpened or deburred perfectly I just don't care. They will still be the sharpest kitchen knives those 30 volunteers have ever used.
 
Nosmo said:
Ben who owns EdgePro once told me that you have to 'cut' the burr off, ( very high angle ) in essence blunting the blade, and then re sharpen stopping just before the burr re forms.
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Have you ever tried that technique? I've seen it mentioned as his method of forming the ultimate edge, but haven't tried it.
 
I,m Going insane here guys!!!!
I read this thread five different times and tried to use all the techniques on some knives i was taking camping this weekend. I could not get a shaving edge from a coarse stone like Cliff Stamp says i can; with the 45 degree angle approach from jeff, I just seem to be dulling my knife (even after regrinding); and Im not seeing a burr at any stage after using these steps, EXCEPT after i progress from my finest stone to my triangular ceramic rod!!!!
NO BURR until I run my already shaving sharp knife over the fine ceramic a few times!! Once it shows up on this sucker, the only thing that gets rid of it is going over it at a REALLY high 45 degree angle like TEN times; and this leaves my actual cutting angle when i whittle or cut anything waaaaaaay too high for me, plus, any ability to shave or slice paper is gone due to the blunt edge!!!
WHAT IS GOING ON HERE????!!!!! :confused:
Could it be that my ceramic is just too worn out to be effective at cutting??
It seems like all my problems are stemming back to that thing. It is pretty old and getting smooth, so maybe it is just abrasive enough to create that micro-burr on an already super- fine edge, but not take it off????
Thank you all for your patience and dilligent responses..
 
bzzhewt said:
I could not get a shaving edge from a coarse stone ...
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There are lots of things you accept as impossible until you have seen it.

I thought ~125 g on light thread was acceptable for sharpness until I tested a bunch of Spyderco's which made me realize my standards were way too low. Now I look at ~90 as decent, and only really see ~75 as acceptable.

I have seen shaving abilities on really coarse edges, it is just a matter of getting the edge alignment and extent of grinding. There are people who can file edges and shave smoothly with them.

Phil Wilson for example prefers the edge the Norton x-coarse SiC hone leaves on his edges, it is very sharp, he has no burr problems though as his steels are usually harder than average at 60+ HRC.

[high burr angles]

... I just seem to be dulling my knife
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Even very high angles can be sharp, they don't of course cut as well as low ones, but they should still slice paper and shave easily, again it is in the alignment.

..Im not seeing a burr at any stage after using these steps, EXCEPT after i progress from my finest stone to my triangular ceramic rod!!!!
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To be clear here, how sharp are the blades before you go to the ceramic rod? It is pretty common for ceramic rods to induce burrs, I found when sharpening Randalls for example that it was easy to get a nice crisp edge on large benchstones, but as soon as I tried to apply micro-bevels with the Sharpmaker it was very difficult to keep the edge crisp. The steels are just too soft to deal with the high pressure created by the low contact areas.

If you are not getting a full crisp edge with the x-coarse hone then the very edge isn't getting hit by the abrasive and thus there is metal left there which has seen extensive use and is likely weakened from fracture or plastic deformation. Thus if this metal finally surfaces on the finer hones, likely just from the repeated abrasion, the resulting edge will be very prone to burring and resisting forming a crisp line.

...this leaves my actual cutting angle when i whittle or cut anything waaaaaaay too high for me, plus, any ability to shave or slice paper is gone due to the blunt edge!!!
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I can understand the first, but the second indicates an odd problem. If I had to guess I would say the edge is cracking off. Does this happen on more than one knife? Can you check out the edge under 10-20 magnification?

Could it be that my ceramic is just too worn out to be effective at cutting??
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If it was perfectly smooth, it would just act as a smooth steel, which would induce a burr but it would not dull the edge unless you used a lot of force, plastically deformed the edge and then it fractured.

What you are sharpening by the way in softer stainless are one of the worst steels to form into a very sharp edge. It is like trying to give a tomcat a bath. Some things can be an exercise in frustration. A really nice steel to sharpen is 52100 at ~60 HRC.

-Cliff
 
I don't have much new information to add, but I can highly recommend the others' suggestions of not just sticking with light p[ressure to remove the burr.

If a blade is messed up enough, it can be real real pain to get rid of the junk steel hanging off of the edge.

The worst one I had to deal with was a Boker Toplock II (420 steel). It came new in the box with not just a burr but a thin flaked layer attached to parts of the edge. I sharpened that damn thing for I don't know how long, and that stupid layer on the edge wouldn't go away. The edge ground down, but the last little bit kept adding to the floppy part.

I had the same problem on a Microtech (not sure if it was ats34/55 or 154cm) which had a nearly useless factory angle. I was impatient and probably used too much pressure trying to grind away the steel to get a new edge, and the same thing happened. I actually didn't use a whole lot of pressure because I had a coarse diamond stone and I was not too careless with a $100 knife, but it still happened.

Same results with a Cold Steel Voyager (AUS8) which I wasn't too careful with because it was a serrated model and I was just grinding it down to some kind of useful edge for the heck of it.

In all cases, I took a grinding device to the knife at 90 degrees (or close to it) and just ground that damn thing off. It's easier to start over with a dull edge than to keep bending that burr or flake back and forth. Once I did that I got them sharpened up fairly easy. I think on one I used a metal impliment to scrape it off instead of the stone. I am fairly sure the Microtech was not as bad as the others, and the Boker was the worst.

Going back in time, I had a burr issue on a G2 Dragonfly. It wasn't as severe as the flaking problem, but it was before I figured it out with the other knives. At the time I didn't even know it was a burr issue, all I knew was the thing wouldn't get sharp. Man was I mad about it!

One thing I learned for sure--light pressure is better for avoiding burrs than getting rid of them. Once you have a major burr problem, it can be a lot easier to just make sure you grind that sucker off.
 
I think I'd try a different ceramic or just skip the ceramic in your process. It sounds like you are fine up to that point. To be honest with you I have never cared much for ceramic anyway and don't use them in my sharpening at all. (if I did it would be a Spyderco and nothing else though) Maybe I'm from the old school because I started sharpening before those were even invented and for myself, I can get better results with Japanese water stones and reprofiles with a diamond stone moving progressivley on the two sided stone to a strop in the last step. If I'm in a real big hurry or have a bundle of knives to do for even faster than the Japanese water stones will cut I'll use my belt sander, and polish the edge with a fiberboard wheel and some white rouge and then strop it, but like I said. I'm old school and old habits die hard.

Have you tried stropping at that point instead of using the ceramic? It sure can't hurt at this point and you said you were quite happy with the edge before the ceramic so it sounds like you just need to eliminate it. Try stropping it on some leather at that step to raise the polish and then blend the micro bevel back into the primary edge grind and go camping.

Wood maybe if you don't have leather, but for me nothing seems to work as good as leather.
 
I am using silicon carbide powder on leather starting from 600 right after Diamond EzeLap and then 1500 silicon carbide and then diamond powder - this way I never experience blurr at all.

600 as I understand corse then Spiderco medium stones.

Probably because leather is soft blurr does never form.

sharpening-01.jpg
 
thombrogan said:
Have you ever tried that technique? I've seen it mentioned as his method of forming the ultimate edge, but haven't tried it.
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Thom,
No......I have not done this yet, but I am going to experiment.
I have got to the sharpening stage that I can flip the burr from side to side with one stroke, but have to be honest and say that I am not sure that my 'burr removal' is also 100%. I suspect I am guilty of 'straightening the burr' on a couple of knives.
 
I see no reason to get too anal about the burr really. This doesn't have to be rocket science. Take the 'grandma approach' and be done with it. My grandma cut in the kitchen and if the knife started dragging or not cutting the fat the way she liked she stropped or steeled it and it either cut or it didn't. I doubt she even knew or much cared what a burr was. Sometimes we just think too much and know too much for our own good. In these situations we are our own worst enemy really.

If the steel is still sound and the burr isn't that long it is probably still a very effective edge anyway so, I'd say just use it. Even if the burr is long it will probably still perform well for most cutting jobs. I doubt seriously that you would notice it unless you were really doing something harder where the edge is going to tear down fast regardless of a burr being there or not.

Besides all this if the steel you happen to have in that knife is prone to burrs there isn't really much you can do about it except keep exercising yourself in frustration by repeating steps over and over again until you have no knife edge left. You'll die before you get rid of that burr if it is one of the more malleable steels. It may be that the steel you have is just too prone to forming fine weak threads when it gets to a certain thinness which would explain the burr showing up when it does there towards that last step when you use the ceramic sharpener.

I guess the best course of action would be to stop right before that step you know is going to cause the burr and just use it at that point where it is a good looking burr free edge.
 
nozh, do you use a trailing motion (edge trailing, like on a regular strop) on the leather in all steps?
 
A few strokes on a ceramic rod does not remove enough material to create a burr (at least in the conventional sense of what constitutes a burr). So all the preceding suggestions for burr removal may be trying to fix the wrong problem. Either you already have a burr before you start on the ceramic rods and somehow the ceramic rods make the burr more noticeable or troublesome, or you are inducing some different problem with how you are using your ceramic rods. How are you determining when you have a burr? Are you really using the same type of inspection at each step?

It is quite common to have a nicely alligned burr on your edge that does a very good job of shaving and light-duty cutting. If you have a troublesome soft alloy it may be very hard to match the cutting performance of that burr with a clean burrless sharpening job. In that case removing the burr will have a maddening tendency to make your blade duller. A lot of these alloys seem to be filled with lumpy chrome carbides that are hard to cut cleanly as you hone. You can sort of line them up, but you can't easily trim them or shape them. A sharp abrasive like a diamond hone can help some. If this is the case you may notice that you get your most effective cutting edge if you strop on leather just a little, very lightly after honing on your finest stone.

The other possibility is that you are causing some other type of degradation to your edge with your ceramic rods. Usually when I use a bench hone I sharpen my knives at a much lower angle than the 15 degrees of the "30 degree" Sharpmaker setup. The lower the angle that you use the more effective that edge will be for shaving. If you've done a good job of manual honing at 10 degrees per side your edge will probably not shave as well if you do any appreciable sharpening at 15 degrees. This is not a matter of a burr or hone material, it is just a matter of angles (10 degrees shaves better than 15 degrees). If you have honed at 10 degrees and suddenly apply strong honing pressure at 15 degrees you will bend your edge sideways by 5 degrees. This could look like a burr, but is really a bent "true edge". Ceramic rods are narrow compared to a bench hone. If your rod is 1/5th the width of your bench hone then you get 5-times the amount of pressure on your edge for a given amount of honing force when you switch to the rod flats. If you switch from honing at 10 degrees to honing at 15 degrees with 5x the amount of pressure on your edge you will deform the edge more than you are honing it. If you use the edge of the rods the pressure goes up around 50x what you had on your flat hone. You will probably not only bend your edge you will probably start to break it through metal fatigue. You need to use a light touch with ceramic rods.

When I sharpen at 10 degrees per side on a bench hone or a sanding belt I normally try and use my Sharpmaker at around the same angle. In order to do this I have to tilt the base as I work. I set one of the Sharpmaker rods crosswise under the center of the base as a fulcrum. I tip the Sharpmaker left and right as I work. When I tilt the base to the right I hone on the left rod and when I tilt the base to the left I hone on the right rod. This is closer to the 10 degree angle that I used with my bench hone. I am careful to use fairly light pressure as I work at this angle, but since I am working at closer to my previous angle my honing pressure is spread over more of the blade surface which reduces the pressure at the edge. I go through the standard Sharpmaker sequence: medium-rod-edges, to medium-rod-flats, to fine-rod-edges, to fine-rod-flats using this technique at 10 degrees. I finish by switching to a pencil as a fulcrum under the base instead of the Sharpmaker rod. I use the same teeter-totter tipping technique and put a micro-bevel on the edge at around 12.5 degrees. I use only the flats of my finest ceramic rods and extremely light pressure.

I don't do any deburring unless it seems indicated. I may do some very light stropping after this step. This will get most alloys to shave pretty well. It will get any alloy that I have seen to do a good cutting job.
 
STR said:
My grandma cut in the kitchen and if the knife started dragging or not cutting the fat the way she liked she stropped or steeled it and it either cut or it didn't. I doubt she even knew or much cared what a burr was. Sometimes we just think too much and know too much for our own good. In these situations we are our own worst enemy really.
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A few years back I gave a 59 HRC fillet knife to a bunch of fisherman who were used to really cheap blades which you maintained with a coarse butchers steel and had to sharpen after pretty much every fish. These were very experienced fisherman, even the "novice" of the group had 25+ years at sea.

I asked them to not hit the knife with the steel, as they would do it out of habit, to keep the knife sharp. They never actually let them dull, it was fillet / steel, repeat. They were all amazed that the knife never needed to be sharpened at all during the cutting, and *many* times over more work was done.

Yes the S90V was a factor as it was harder, more corrosion resistant and far more abrasion resistant than the blades they were using. However the sharpening method was also a huge factor. Later on I sharpened a couple of the old ones and got a crisp edge and gave them to another few guys.

One of them started steeling out of habit and the edge retention was horrible, the other guy didn't and let the edge run its course and he processed many times over more fish. A steeled edge is really weak compared to a freshly honed edge and has a small fraction of the edge retention.

You can't use the same methods on the softer carbon steels as the newer and harder high alloy steels and expect similar behavior, plus there is a lot more performance there if you maximize the steel by taking advantage of what it can do.

My grandmother was also trivial about sharpening and used a rock on the wall outside her house, my grandfather (carpenter) had much higher standards for sharpness and edge retention for his tools. If you took one of his carving knives, chisels or axes to the rock - well I don't know what would happen, but it likely would not be pleasant.

Of course you have to factor your skills into the equation, right now I tend to see about 75% of optimal sharpness (~75 g on light thread) as acceptable when I sharpen my knives and I am pleased when I go above that. Some knives are easier to get there than others. On some making even 50% is decent.

-Cliff
 
It seems to me if you have repeatedly noticed that a burr is forming after the ceramic rods and the edge was burr free before that, that what you are seeing is not a 'true burr' or there is a burr before you get there and you just don't notice it as much but there have been times in my experience when I would swear that the ceramic rods brought up the burr. Probably not the case I guess but it wasn't noticed before the rods were used..

If this is the case you may notice that you get your most effective cutting edge if you strop on leather just a little, very lightly after honing on your finest stone.
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I'm glad Jeff put this here because it is exactly what I suggested earlier when I said to skip the ceramic rod step and use a leather strop. Some steels respond better to stropping.

I asked them to not hit the knife with the steel, as they would do it out of habit, to keep the knife sharp. They never actually let them dull, it was fillet / steel, repeat. They were all amazed that the knife never needed to be sharpened at all during the cutting, and *many* times over more work was done.
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Yes, when I took a carving class one of the biggest obstacles for the teacher was to condition the guys to not sharpen so frequently and change the way they were used to doing things. Making them use the knife without the benefit of the strop right there in front of them was the only way to keep some of them from using it. The definition of "dull" is different from one person to the next.
 
Thank you all for helping with one of the best threads I have ever read. I have learned a ton.
Cliff, as a side note, i am very intrigued as to how one would go about getting a usable, shaving sharp edge from a coarse stone. I do not think it is impossible, i just said i have never done it. Any pointers?
 
bzzhewt said:
I do not think it is impossible ...
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That was more of my perspective, before I read about it and saw it first hand. There is nothing any different in the sharpening, just make sure your stone is clean and flat. In general I find coarser hones generally easier to get sharper blades as the micro teeth are more forgiving to alignment when they are larger so you can be sloppier. To take all the guesswork out of it, just shape the angle freehand, and the v-rod a micro bevel with your coarse hone by making something similar to the Sharpmaker or the Razor Edge Guides.

-Cliff
 
HoB said:
nozh, do you use a trailing motion (edge trailing, like on a regular strop) on the leather in all steps?
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Yes, edge face me and I move it away when sharpening. I notice that it starts shaving later and I need a bit more effort do have it shave then on ceramic. And I use that triangilar base to keep right angle. I always keep one angle and never raise it to get rid of the burr - I don't have it at first place.

But this shaving ability is even on left and right sides. It is burr what make knife shave earlier I think, and you may detect it shaving by left and right sides of the blade. If burr is there - usually bended on one side - it shave in one case and did not in another.

Thanks, Vassili.
 
Hey, Vassili,
Do you still use your waterstone? Have you tried sharpening your higanokami on the strops and have you tested them for thread cutting?
 
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