I love my small Sebenza but I hate sharpening the thing. I profiled to 20 degrees on the Sharpmaker which took forever due to the lack of an aggressive cutter on the 204 and due to the high Rc of the Sebby. When that was done I went about polishing up the edge on a belt with some Flitz on it to give the edges that mirror look when it was NIB. When I stropped the Sebby I must have overdone it and rounded over the edge because it would not shave hair easily and it struggled to cut through paper. So off again to the Sharpmaker. I used the fine rods for about 15 strokes per side and the knife showed no improvement. So I marked the edge with a permanent marker it to my surprise, I still had a little black line at the edge, meaning I was not raising a burr. But how could this be?. When I originally reprofiled on the 204, I used the marker and I'm sure I raised a burr. So in go the medium rods. After about 50 strokes I raise the burr and work up to the fine rod and then finally its time to strop. Before stropping, entire edge is popping hair. After I strop on untreated leather belt, the edge up to and including the belly is scary hair poppin sharp but the quarter inch to the tip will barely cut hair. So I go back to the fine rods on the sharpmaker and now I can't raise the burr on the edge with the fine rods. I guess the med rods are back up after work. What the **** is my problem. I didn't overstrop this last time and the rest of the edge turned out fine after stropping. So why is the tip and screwed up? Anybody else having these problems or am I an original. BTW, I sharpen all my knives this way and they all turn out wicked sharp. Am I missing something with the BG-42? Is it possible that I have a Sebby with defective heat treat because it seems impossible with the impeccable quality of CR Knives. Comments welcome and appreciated.
Sharpening the Sebenza. Arrrgg.
- Thread starter kutch133
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Question - Are you stropping the edge at the proper angle? If you're rolling the edge by stropping, you ought to be able to feel the edge roll.
Personally, I only use the angled sides of the SharpMaker for my Sebenza. The flat sides seem to throw my sharpening into an utter state of confusion and dullness. Also, I haven't really found any reason to strop after the fine rods.
Personally, I only use the angled sides of the SharpMaker for my Sebenza. The flat sides seem to throw my sharpening into an utter state of confusion and dullness. Also, I haven't really found any reason to strop after the fine rods.
Esav Benyamin
MidniteSuperMod
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This is an interesting problem. I'd like to know why you aren't getting consistent results.
My Sebenza cuts up fruits and vegetables practically every day. When I walk through the woods, it gets gunked up with plant juice when I slash off the weeds along the trail. I cut some tape and cardboard.
I keep it clean, water or soap and water, and dry. I touch it up on the Sharpmaker, white rods, edge only, at 20 degrees, maybe 10 strokes each side.
Am I wrong, or does the Sharpmaker, by alternating strokes to each side, eliminate the burr by itself? As I understood the instructions, only when sharpening a chisel grind on the one side only do we have to throw in an occasional stroke on the other side to keep the burr down.
My Sebenza cuts up fruits and vegetables practically every day. When I walk through the woods, it gets gunked up with plant juice when I slash off the weeds along the trail. I cut some tape and cardboard.
I keep it clean, water or soap and water, and dry. I touch it up on the Sharpmaker, white rods, edge only, at 20 degrees, maybe 10 strokes each side.
Am I wrong, or does the Sharpmaker, by alternating strokes to each side, eliminate the burr by itself? As I understood the instructions, only when sharpening a chisel grind on the one side only do we have to throw in an occasional stroke on the other side to keep the burr down.
Hi,
Just my view.
From what I hear, CRK sharpens to a convex edge rather that the usual straight one. So, if this is your first sharpening and you are not planning on sharpening to the orginal edge shape, you will spend A TON of time (especially with the Sharpmaker)wearing down the sides of the convex edge to get the typical "V" shaped one. The Sharpmaker does not have stones coarse enough to remove metal quickly.
Since I do not have the experience to create a convex edge, I used a coarse DMT bench stone and ground the bevels flat. I dont know what angle, but the bevels seem to be the original size, and they are pretty much even on each side. Then, I proceeded to hand sharpen using the Sharpmaker in "bench-stone-mode" and clean up the edge a bit, followed by stropping with leather and Flitz.
I got good results but not as polished as the CRK edge, not quite as keen, and the edge did not last as long.
Recently, I have been REALLY lucky, and Tom Mayo has put his polished edge on my UCG Classic...WOW!!!!! He uses belts and buffers to get his convex edge. But hey, he sharpens stuff for a living and is known for his SHARP edges.
Aloha
Reread your post, and I missed the part where you said you had already reprofiled...in that case, sorry, no insight....
Aloha #2
Just my view.
From what I hear, CRK sharpens to a convex edge rather that the usual straight one. So, if this is your first sharpening and you are not planning on sharpening to the orginal edge shape, you will spend A TON of time (especially with the Sharpmaker)wearing down the sides of the convex edge to get the typical "V" shaped one. The Sharpmaker does not have stones coarse enough to remove metal quickly.
Since I do not have the experience to create a convex edge, I used a coarse DMT bench stone and ground the bevels flat. I dont know what angle, but the bevels seem to be the original size, and they are pretty much even on each side. Then, I proceeded to hand sharpen using the Sharpmaker in "bench-stone-mode" and clean up the edge a bit, followed by stropping with leather and Flitz.
I got good results but not as polished as the CRK edge, not quite as keen, and the edge did not last as long.
Recently, I have been REALLY lucky, and Tom Mayo has put his polished edge on my UCG Classic...WOW!!!!! He uses belts and buffers to get his convex edge. But hey, he sharpens stuff for a living and is known for his SHARP edges.
Aloha
Reread your post, and I missed the part where you said you had already reprofiled...in that case, sorry, no insight....
Aloha #2
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Interesting this, perhaps the fitz is over abrasive or the belt is so slack that the edge is rounding to the point of dullness? I intend to use a leather belt quite slack with some Chrome polish as a strop to keep the convex edge on my CRK and my Spyderco Moran. Perhaps the stones on your 204 are in need of a good clean as they may be clogged up with metal, same goes for the strop? Hope it helps.
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I have had similar results with a spyderco delica as well as my sebenza. I will finish on the flat whites and it is RAZOR sharp. Then i will strop and I either don't notice an improvement or I get a duller edge. I am starting to dislike stropping. It seems pointless and I cannot make out any improvement. I am NOT raising up at the end of the stroke either, I lift straight off. Also I wipe down the edge with my shirt to get all the grit off before stropping. The edge is very sharp and feels real straight after the flat sides of the white stones. I read in a Dick tools catalog that the Japanese sword maker does not use leather strops for the simple reason that there is a chance that the leather can dull it by rounding over the edge. Also I would find it difficult stropping a sword on anything other than a leather belt on a sander. I just don't know.
Went back to the med stones and finally raised a burr. It is posible that I hadn't raised a burr before. I don't know. Anyway, I got the entire edge poppin sharp, in fact sharper than the factory edge. I think the problem I was having sharpening the Sebbie was in fact because the factory edge is convex. It takes forever to get the v-grind. This raises some questions in my mind. Why does CR Knives put a convex edge on the Sebenza and then recommend the Sharpmaker which puts a v-grind on the edge, knowing the difficulty in doing so?
Will CR Knives put a v-grind as the factory edge upon request? Is there any advantages or disadvantages of the convex vs. v-grind? Am I rambling on senselessly.
Will CR Knives put a v-grind as the factory edge upon request? Is there any advantages or disadvantages of the convex vs. v-grind? Am I rambling on senselessly.
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The Convex edge is quite simply the Ferrari of edge styles, it is amazingly sharp, while still having reasonable edge strength. Many here recomment using a strop slackly to re-sharpen the convex edge, that is what I will do. The Convex edge is also called a rolled edge or a Moran edge. It is a benifit to get this on a knife and while few have the skill to keep such and edge (done using a slack belt sander) there are few knives as sharp as a Sebi out of the box.
Do you want your Ferrari with small tires as they are cheaper and easier to get? No, the Benza is a performance machine and you can't blame it if it is too good? The Vee grind is not that hard to put on after all and you need only re-profile this once.
Do you want your Ferrari with small tires as they are cheaper and easier to get? No, the Benza is a performance machine and you can't blame it if it is too good? The Vee grind is not that hard to put on after all and you need only re-profile this once.
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It sounds to me like CRK uses a variety of edge types. I have heard of the "flat ground Sebenza" and now am hearing that they are "convex ground". But looking at my Classic MM, it is hollow ground with "V" cutting edges.
As for stropping, a lot of folks strop at too high of an angle and since the leather "rolls" as the blade moves accross it then the cutting edge gets rolled away. Lay the blade flat on the strop and just raise it about 10-15 degrees MAX. and then move the blade AWAY from the cutting edge. It takes a lot of stropping to make any difference to an already sharp edge as it just a polishing mode.
As for stropping, a lot of folks strop at too high of an angle and since the leather "rolls" as the blade moves accross it then the cutting edge gets rolled away. Lay the blade flat on the strop and just raise it about 10-15 degrees MAX. and then move the blade AWAY from the cutting edge. It takes a lot of stropping to make any difference to an already sharp edge as it just a polishing mode.
Esav Benyamin
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The Sebenza is hollow ground, which is concave, not convex, this is, it bows inward, not outward. But the secondary bevel is convex, rather than the simpler v-grind that a sharpener like the Sharpmaker naturally puts on a blade.
I think if you go for a thirty degree bevel with the Sharpmaker, you will end up reprofiling -- at great cost of time and effort. If you go for the forty degree, you will re-establish the cutting edge fairly close to the original.
So, use the thirty degree lightly to reprofile only the shoulders of the bevel, above the actual cutting edge, and then use the forty degree for the edge. You should end up with a double angle in place of the smooth convex curve of the original edge, but it is a good approximation.
Unless your Sebenza is really getting heavy use, and you feel the edge has degraded seriously, you should be able to get by with the white rods, edge on, not flat, maybe ten strokes each side.
I think if you go for a thirty degree bevel with the Sharpmaker, you will end up reprofiling -- at great cost of time and effort. If you go for the forty degree, you will re-establish the cutting edge fairly close to the original.
So, use the thirty degree lightly to reprofile only the shoulders of the bevel, above the actual cutting edge, and then use the forty degree for the edge. You should end up with a double angle in place of the smooth convex curve of the original edge, but it is a good approximation.
Unless your Sebenza is really getting heavy use, and you feel the edge has degraded seriously, you should be able to get by with the white rods, edge on, not flat, maybe ten strokes each side.
Kutch:
I don't claim to be an "expert", or have any enlightening wisdom. However, I've found that if I take a good, close look at a blade before putting it to the stone, I can develop a pretty good strategy for sharpening it. Some blades, depending on the grind style, how they "thicken" towards the tip, etc... can be real challenging. Some of these are too challenging for me and my EdgePro and I don't even attempt it. I don't sharpen a blade unless I'm sure that I'll get excellent results.
Here's what's unique about a Sebenza blade. It's extremely thin, but thickens considerably (relative to the thinness further back) towards the tip, for a strong point. CRK uses a wheel to produce their polished edges. With this method, they raise the blade a little as they approach the tip. Otherwise, the edge grind would widen, would not look right and the tip would be weak. What I'm saying is, is that the edge is ground at a slightly greater angle out towards the tip. Another characteristic of using a wheel is that you get sort of a convex edge grind. The blade is hollow ground, not convex. The way CRK does it, is excellent and probably the best way. But, it's impossible for anyone using a Sharpmaker, Edgepro, etc...you need a wheel.
My Edgepro will put a nice, uniform V-grind on the edge. I don't really know (or care) what angle I use. Taking magic marker as a reference guide, I adjust the angle to equal the angle it's already ground at midway down the blade. I then position the blade on the Edge Pro so that the curve is off the end of my guide table and actually curves towards the pivot, thereby slightly increasing the angle of the grind as I work out towards the tip. I use a fairly coarse stone to even out the edge and produce a uniform burr. After 220 grit, I use 600 and then 3000 to produce a high polished edge. This edge is awesome and holds very well. It's way beyond simply being able to shave hair. After going through this whole procedure, which produces a really nice, evenly ground edge, all that I do for subsequent sharpenings is use 3000 to touch it up. Sometimes, if it's too far gone, 600 is used to raise a burr, and then back to 3000.
Anyway, that's probably why you raised a good burr and wound up with a sharp edge, except for out near the tip. If you force the issue and try to take the exact same angle all the way to the tip, you'll ruin the blade. The area directly behind where the blade starts to thicken towards the tip, will hollow out. If fact, be careful not too let this happen during normal sharpening. Might consider sending it to CRK and then as you use it, just touch it up frequently on a very fine stone or steel. If you do this often, you can maintain a great edge for a very long time.
Pete Bransky
I don't claim to be an "expert", or have any enlightening wisdom. However, I've found that if I take a good, close look at a blade before putting it to the stone, I can develop a pretty good strategy for sharpening it. Some blades, depending on the grind style, how they "thicken" towards the tip, etc... can be real challenging. Some of these are too challenging for me and my EdgePro and I don't even attempt it. I don't sharpen a blade unless I'm sure that I'll get excellent results.
Here's what's unique about a Sebenza blade. It's extremely thin, but thickens considerably (relative to the thinness further back) towards the tip, for a strong point. CRK uses a wheel to produce their polished edges. With this method, they raise the blade a little as they approach the tip. Otherwise, the edge grind would widen, would not look right and the tip would be weak. What I'm saying is, is that the edge is ground at a slightly greater angle out towards the tip. Another characteristic of using a wheel is that you get sort of a convex edge grind. The blade is hollow ground, not convex. The way CRK does it, is excellent and probably the best way. But, it's impossible for anyone using a Sharpmaker, Edgepro, etc...you need a wheel.
My Edgepro will put a nice, uniform V-grind on the edge. I don't really know (or care) what angle I use. Taking magic marker as a reference guide, I adjust the angle to equal the angle it's already ground at midway down the blade. I then position the blade on the Edge Pro so that the curve is off the end of my guide table and actually curves towards the pivot, thereby slightly increasing the angle of the grind as I work out towards the tip. I use a fairly coarse stone to even out the edge and produce a uniform burr. After 220 grit, I use 600 and then 3000 to produce a high polished edge. This edge is awesome and holds very well. It's way beyond simply being able to shave hair. After going through this whole procedure, which produces a really nice, evenly ground edge, all that I do for subsequent sharpenings is use 3000 to touch it up. Sometimes, if it's too far gone, 600 is used to raise a burr, and then back to 3000.
Anyway, that's probably why you raised a good burr and wound up with a sharp edge, except for out near the tip. If you force the issue and try to take the exact same angle all the way to the tip, you'll ruin the blade. The area directly behind where the blade starts to thicken towards the tip, will hollow out. If fact, be careful not too let this happen during normal sharpening. Might consider sending it to CRK and then as you use it, just touch it up frequently on a very fine stone or steel. If you do this often, you can maintain a great edge for a very long time.
Pete Bransky
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You will ruin the blade by sharpening it at 20 per side on a Sharpmaker? WHAT? So if the blade is from tip to tang sharpened at the same angle it will ruin it? You cannot be serious?
I know of a lot of people that sharpen at 20 per side on the white stones and have done for years with no problems, I think you exaggerate the situation. I think you are right about the different angle, but this is common on many knives I have seen, I have to disagree that the knife would be ruined.
Anyone else?
I know of a lot of people that sharpen at 20 per side on the white stones and have done for years with no problems, I think you exaggerate the situation. I think you are right about the different angle, but this is common on many knives I have seen, I have to disagree that the knife would be ruined.
Anyone else?
General:
Did I say that if take 20 passes on a sharpmaker, that you would ruin the blade?
No, I did not.
Did I say that if you use the same sharpening angle from tip to tang that you would ruin the blade?
No, I did not.
What I DID say, was that if you took the same angle all the way through to the tip, you would ruin the blade. Maybe I wasn't clear enough, but that means if you reprofiled the edge, trying to grind in the same angle and raise a burr all the way through to the tip, you would thin it out considerably at the tip, weaken the tip and also cause a hollow area to appear at the point where the edge profile goes from thin to thick.
Like I said, I'm not the world's greatest authority on sharpening, but I get good results. Real good. I also don't post comments and suggestions if I don't know exactly what I'm talking about. As AG Russell has written, when sharpening on a flat stone, you lift the knife in order to increase the sharpening angle as you're moving out onto the tip. It's a basic and necessary technique for most knives.
I felt like I could give valuable info here as a solution to the problem, as I understood it to be. I'm not too excited about having to post again for the sake of someone who has not carefully read my post, or is just looking to be arguementative. I feel these forums are slipping in quality as a result of those who have nothing of value to contribute, but post in order to spark feuds. If someone needs further clarification on my sharpening point, I'm happy to help. I won't, however, argue my point. It's pretty simple sharpening theory.
Pete
Did I say that if take 20 passes on a sharpmaker, that you would ruin the blade?
No, I did not.
Did I say that if you use the same sharpening angle from tip to tang that you would ruin the blade?
No, I did not.
What I DID say, was that if you took the same angle all the way through to the tip, you would ruin the blade. Maybe I wasn't clear enough, but that means if you reprofiled the edge, trying to grind in the same angle and raise a burr all the way through to the tip, you would thin it out considerably at the tip, weaken the tip and also cause a hollow area to appear at the point where the edge profile goes from thin to thick.
Like I said, I'm not the world's greatest authority on sharpening, but I get good results. Real good. I also don't post comments and suggestions if I don't know exactly what I'm talking about. As AG Russell has written, when sharpening on a flat stone, you lift the knife in order to increase the sharpening angle as you're moving out onto the tip. It's a basic and necessary technique for most knives.
I felt like I could give valuable info here as a solution to the problem, as I understood it to be. I'm not too excited about having to post again for the sake of someone who has not carefully read my post, or is just looking to be arguementative. I feel these forums are slipping in quality as a result of those who have nothing of value to contribute, but post in order to spark feuds. If someone needs further clarification on my sharpening point, I'm happy to help. I won't, however, argue my point. It's pretty simple sharpening theory.
Pete
Pete, actually I am confused about what you said. Could you explain further what you mean? I used the 20 degree angle on my Sebenza and did finally raise a burr near the tip. In the process, the bevel on the actual cutting edge widened near the tip, not much but it did widen. Is this what you were referring to as ruining the blade? If that is the case, why would CR Knives recommend the Sharpmaker? BTW, it was posted that the convex edge is sharper than the v-grind. Truth be told, my Sebenza is sharper now after running it through the Sharpmaker than it was when I received it NIB in a trade. It seems to me that the more experience I get sharpening my knives, the less I actually know about sharpening.
Kutch:
The reason that the grind widens towards the tip as you sharpen using the same angle is because the blade thickens towards the tip. You have to remove a significant amount of metal, which weakens the tip. Also, as you grind away, trying to thin out the tip, you quickly get a burr in the area behind the tip where the blade profile is thinner. Further grinding in this area will hollow it out. This is the same thing that happens at the rear of a lot of forged blades that don't have a choil cutout. The area where the edge actually starts is thinner than the area behind it and hollows out if too much sharpening is done in that area. When I made reference to ruining the blade, I was specifically referring to weakening the tip and ruining the edge profile behind the tip. I think the blade profile on the Sebenza is fantastic. Very thin in the areas where you can get away with it. This makes it a great cutter. Stout enough at the tip. Strong spine. The Sebenza is not a convex grind. It's hollow ground. An Ed Fowler knife is a good example of a true convex grind. The Sebenza edge is not perfectly flat simply because it's sharpened on a buffing wheel, which rounds it out just the slightest bit.
CRK recommends the sharpmaker for good reason. They prefer and recommend that their customers MAINTAIN the edges on their knives, versus letting the edges get too far gone and need to be re-profiled. A sharpmaker is excellent and easy to use for maintaining the edge. I would recommend the sharpmaker for this use and have Chris Reeve tackle the job of regrinding or re-profiling a blade. I've maintained edges on my Sebenzas razor sharp for more than a year with moderate use with nothing more than fine stones (600 and 3000).
Believe me, I know what you mean concerning the mysteries of sharpening. I feel the same way. I've learned a few basic things through trial and error and messing up quite a few blades (including ruining a perfectly fine Sebenza blade once.) One thing to realize is that there are tradeoffs and you have to have a goal in mind when you sharpen. If you thin out the profile of a blade significantly, you can get it extremely sharp. But, it will also be extremely weak, will chip easily and will wear quicker. Tradeoffs. For me, I try to stay very close to the original profile, even out the factory edge grind and create a nice polished edge. Take care and I hope this helps,
Pete
The reason that the grind widens towards the tip as you sharpen using the same angle is because the blade thickens towards the tip. You have to remove a significant amount of metal, which weakens the tip. Also, as you grind away, trying to thin out the tip, you quickly get a burr in the area behind the tip where the blade profile is thinner. Further grinding in this area will hollow it out. This is the same thing that happens at the rear of a lot of forged blades that don't have a choil cutout. The area where the edge actually starts is thinner than the area behind it and hollows out if too much sharpening is done in that area. When I made reference to ruining the blade, I was specifically referring to weakening the tip and ruining the edge profile behind the tip. I think the blade profile on the Sebenza is fantastic. Very thin in the areas where you can get away with it. This makes it a great cutter. Stout enough at the tip. Strong spine. The Sebenza is not a convex grind. It's hollow ground. An Ed Fowler knife is a good example of a true convex grind. The Sebenza edge is not perfectly flat simply because it's sharpened on a buffing wheel, which rounds it out just the slightest bit.
CRK recommends the sharpmaker for good reason. They prefer and recommend that their customers MAINTAIN the edges on their knives, versus letting the edges get too far gone and need to be re-profiled. A sharpmaker is excellent and easy to use for maintaining the edge. I would recommend the sharpmaker for this use and have Chris Reeve tackle the job of regrinding or re-profiling a blade. I've maintained edges on my Sebenzas razor sharp for more than a year with moderate use with nothing more than fine stones (600 and 3000).
Believe me, I know what you mean concerning the mysteries of sharpening. I feel the same way. I've learned a few basic things through trial and error and messing up quite a few blades (including ruining a perfectly fine Sebenza blade once.) One thing to realize is that there are tradeoffs and you have to have a goal in mind when you sharpen. If you thin out the profile of a blade significantly, you can get it extremely sharp. But, it will also be extremely weak, will chip easily and will wear quicker. Tradeoffs. For me, I try to stay very close to the original profile, even out the factory edge grind and create a nice polished edge. Take care and I hope this helps,
Pete
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edit:didn't notice Pete's last post, and see he explained it in greater detail, already.
Butting in.....
Farmer's right, and it's easy to illustrate (assuming your edge bevel is even all the way to the tip).
Put a rod in the Sharpmaker, line up the edge bevel with the stone at the choil. Lean over so you can watch the edge travel down the stone. As you reach the front of the belly, you will have to raise your wrist, and your hand will rotate inward (between the rods) to keep the edge bevel flat on the stone.
Why? Because it's thicker at the tip, and the angle is more obtuse. Otherwise the edge bevel would increase in height as the edge traveled up to meet the spine at the tip-the thickest part of the edge.
This becomes more obvious the larger (thicker) the knife, and is really easy to see on large fixed blades.
Butting in.....
Farmer's right, and it's easy to illustrate (assuming your edge bevel is even all the way to the tip).
Put a rod in the Sharpmaker, line up the edge bevel with the stone at the choil. Lean over so you can watch the edge travel down the stone. As you reach the front of the belly, you will have to raise your wrist, and your hand will rotate inward (between the rods) to keep the edge bevel flat on the stone.
Why? Because it's thicker at the tip, and the angle is more obtuse. Otherwise the edge bevel would increase in height as the edge traveled up to meet the spine at the tip-the thickest part of the edge.
This becomes more obvious the larger (thicker) the knife, and is really easy to see on large fixed blades.
Owen, so if I rotate my wrist upward, as I have been doing, I'll remain truer to the original grind without sacrificing the tip. As I sit here and look at my Sebenza I do notice that near the tip the bevel is a few hairs wider that the rest of the blade. But now, I can just take the flat white stones and maintain the edge. I am no expert by any means in shapening but the Sharpmaker gives the average Joe like me the ability to put a mean edge on a blade. I feel that I've achieved the edge that I want on the Sebenza and I feel no need to send my Sebby back to CR Knives. Besides, wouldn't they regrind it to how it originally was and I would have to start all over again with the Sharpmaker?