WSKO: some knives not as sharp as others

chado skins, let me add one more suggestion. Sometimes, as I get to the end of a belt progression on the KO, the knife has a nice polished bevel but is not as sharp as it should be. As Brian mentioned, this is likely due to not hitting the apex with the finer belts. If I can't resolve the situation with a few additional passes, I will take the knife off the KO and apply another method, usually my Sharpmaker. That will get it apexed properly, and then I'll go back to the KO to finish polishing it with the fine belts.

Andrew
 
I'd suggest try with your new Henckels. That way you can be sure it's not the steel ;)

Kitchen knives should do well with 30 inclusive.
 
AFAustin said:
T... the Twilight Zone.

Oddly, another steel which has given me problems on the KO is at the other end of the quality scale: CPM 3V. On a couple of occasions I've had nice Bark Rivers in 3v come my way and I've only been able to manage a "working edge" on them with the KO. They weren't my knives so I didn't keep at it too long for fear of removing too much metal on someone else's knife, but I was disappointed as I can always get a beautiful edge on Barkies with A2....
Andrew
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Say it ain't so Andrew! Lord knows I wasn't considering purchasing a KOWS to sharpen my A2, O1, D2 blades... Headthunk.
 
anyone have any suggestions on belt speed for the KO? seems the manual suggests low speed for just about everything, anyone use higher speeds?
 
I call the lowest speed 1 and the highest 14. I spend most of my time on speeds 6 - 8. To me that has the best combination of grinding speed while not being overly loud.

Occasionally I do a blade at speed 3 but usually only very thin blades.

I deburr at speed 1 always. BTW I do all of this free hand. I have never used the guide.

Good luck and let us know how you do. :)

Brian.
 
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not hitting the apex=uneven bevel, correct? meaning the bevel is not the same on both side of the knife... i have a beater knife that has some pretty deep nicks in it. starting on the extra coarse belt, i know i'll have to take off enough material to set a new bevel, so is feeling for a burr on this belt even still necessary? i'm thinking i'll alternate passes, extra corase, medium speed until i've removed enough material to take the nicks out. any issues with this methodology?
 
i was able to put a pretty good edge on the beater. the difference was i spent a long time on the extra coarse belt. like a really long time. i don't think i had a real appreciation for how much time it takes to take material off a knife to create a new bevel. it takes some effort. i let the belt fly on high. it's a beater knife that no one will miss so i figured i'll give it a shot. after a about a half hour of grinding with alternating passes, the nicks came out and it had a nice edge. i progressed through the belts and shes pretty sharp now, and looks nice. i'm thinking the culprit all along was that i wasn't taking enough material off with the coarse belts to really make a new bevel. this information wasn't really specified in the manual... the manual makes it sound like 10 passes on the x65 belt and boom! sharp knives! not so much. i let that extra coarse belt fly and it STILL took a while. good news i think i figured out how to get knives sharp. the bad news is that it takes so long it doesn't seem like it could be workable into a business model to sharp knives for some extra cash/new business.
 
chado skins said:
not hitting the apex=uneven bevel, correct?
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Not exactly. The apex is simply the edge of the edge. The part of the blade that cuts. A lot of times when we are grinding the edge bevel on a blade, we end up grinding near the shoulder of the blade, as opposed to down near the cutting edge. In those cases you can grind and grind and never touch the edge of the edge, and therefore it won't ever get sharp. In other cases, the grind of the edge bevel will be poor from the factory, or from use, or some other reason. In those cases, sometimes it takes quite a bit of grinding to make the bevel nice and flat and even, and you'll end up removing quite a bit of metal before you actually reach the apex: The cutting edge.

starting on the extra coarse belt, i know i'll have to take off enough material to set a new bevel, so is feeling for a burr on this belt even still necessary?
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I think it is always necessary to raise a burr when sharpening and to make sure it's raised on the entire length of the edge on BOTH sides (one side and then the other). Until you do this, you won't really reach the potential of the blade IMHO.

Brian.
 
all of the knives that i sharpened today feel much better than when i tried to sharpen them before. before i did get burrs. this time i alternated passes, spent more time on the coarser belts, and just sharpened until it felt sharper. they did seem to feel less sharp after i progressed, mostly after x4. i'm guessing this is because the edge is less "toothy", and that the edge isn't actually less sharp. i'm getting a better feel for how the knife follows the guides. i also dialed down the bevel to 15 degrees as suggested. maybe that's the difference. who knows. we'll see how they perform, some were my personal knives, one was a friends, another a house knife.
 
bgentry said:
Not exactly. The apex is simply the edge of the edge. The part of the blade that cuts. A lot of times when we are grinding the edge bevel on a blade, we end up grinding near the shoulder of the blade, as opposed to down near the cutting edge. In those cases you can grind and grind and never touch the edge of the edge, and therefore it won't ever get sharp. In other cases, the grind of the edge bevel will be poor from the factory, or from use, or some other reason. In those cases, sometimes it takes quite a bit of grinding to make the bevel nice and flat and even, and you'll end up removing quite a bit of metal before you actually reach the apex: The cutting edge.



I think it is always necessary to raise a burr when sharpening and to make sure it's raised on the entire length of the edge on BOTH sides (one side and then the other). Until you do this, you won't really reach the potential of the blade IMHO.

Brian.
Click to expand...

thanks for clarifying on apex. seems a weird concept to sharpen a knife but never get it sharp...
 
chado skins said:
i was able to put a pretty good edge on the beater. the difference was i spent a long time on the extra coarse belt. like a really long time.
Click to expand...

Awesome! You're learning several of the secrets of sharpening here and this is definitely one of them. It's #7 of my unofficial 7 Secrets Of Sharpening. Spend your time on the coarse belt! By "extra coarse", I'm assuming you mean the P120 belt that came with the WSKO. I was initially very cautious with that belt, but I quickly learned to use it on almost every blade I did. In fact, I think it's not nearly coarse enough for really major jobs. So I'm thrilled that Darex now offers several really good coarse belts that surpass the P120: 60 grit ceramic, 80 grit ceramic, and X200 stiff (200 micron Norax). All three belts are very good, with the 60 being the most abrasive and the X200 being the combination of a fast grinder, but leaving a more refined finish.


after a about a half hour of grinding with alternating passes, the nicks came out and it had a nice edge.
Click to expand...

I've noticed something using both diamond plates and the WSKO with chips: It seems like the chips seem to hang on for much longer than they should when doing regular sharpening at the intended angle. It's almost like the abrasive digs into the chip and makes it slightly deeper, so that you grind the top of the chip away, but the bottom gets deeper. Eventually it's all gone, but it seems to take far more grinding that I'd expect.

So I've now adopted something Jason B suggested, which is to "cut off the edge" on badly damaged or chipped blades. Jason would tell you to hold the blade 90 degrees to the stone (or belt) and grind the edge flat until the chips are gone and the blade has the approximate shape you want. With the WSKO it's sort of hard to do grinding at 90 degrees because there's no tool rest or platen. So I grind at something like 60 to 75 degrees on each side and cut off the edge, removing the chips and reshaping the blade until I think it's ready. Then I go back to the proper sharpening angle and re-establish a new bevel at the intended angle (something like 15 degrees per side on many blades).

Doing this with the 60 grit ceramic is surprisingly fast, even at speed 7 or so. You have to be careful because the scratch pattern is so coarse and messy, plus that belt is so abrasive that it can throw sparks, which to me means I'm grinding too fast. I haven't had any issues with it yet other than some scratches on the sides of blades here and there.

I'm glad you're making good progress. You're on your way.

Brian.
 
bgentry said:
Awesome! You're learning several of the secrets of sharpening here and this is definitely one of them. It's #7 of my unofficial 7 Secrets Of Sharpening. Spend your time on the coarse belt! By "extra coarse", I'm assuming you mean the P120 belt that came with the WSKO. I was initially very cautious with that belt, but I quickly learned to use it on almost every blade I did. In fact, I think it's not nearly coarse enough for really major jobs. So I'm thrilled that Darex now offers several really good coarse belts that surpass the P120: 60 grit ceramic, 80 grit ceramic, and X200 stiff (200 micron Norax). All three belts are very good, with the 60 being the most abrasive and the X200 being the combination of a fast grinder, but leaving a more refined finish.




I've noticed something using both diamond plates and the WSKO with chips: It seems like the chips seem to hang on for much longer than they should when doing regular sharpening at the intended angle. It's almost like the abrasive digs into the chip and makes it slightly deeper, so that you grind the top of the chip away, but the bottom gets deeper. Eventually it's all gone, but it seems to take far more grinding that I'd expect.

So I've now adopted something Jason B suggested, which is to "cut off the edge" on badly damaged or chipped blades. Jason would tell you to hold the blade 90 degrees to the stone (or belt) and grind the edge flat until the chips are gone and the blade has the approximate shape you want. With the WSKO it's sort of hard to do grinding at 90 degrees because there's no tool rest or platen. So I grind at something like 60 to 75 degrees on each side and cut off the edge, removing the chips and reshaping the blade until I think it's ready. Then I go back to the proper sharpening angle and re-establish a new bevel at the intended angle (something like 15 degrees per side on many blades).

Doing this with the 60 grit ceramic is surprisingly fast, even at speed 7 or so. You have to be careful because the scratch pattern is so coarse and messy, plus that belt is so abrasive that it can throw sparks, which to me means I'm grinding too fast. I haven't had any issues with it yet other than some scratches on the sides of blades here and there.

I'm glad you're making good progress. You're on your way.

Brian.
Click to expand...


yes by extra coarse i am describing the p120 that came with the wsko. the belts that came with it are the only ones i have. i was operating mostly from the manual's information, it only had p120 listed for knife repair... but as you said, i think starting with that belt on all the knives, they feel so much better to me. and yes it did seem to take a long time to grind those nicks out... even at high belt speeds... interesting idea about griding at a wider angle.
 
i took four knives to the KOWS today. all of them being on a dull side. of the eight sides, i could raise exactly one burr. i tried both the P120 extra corase belt and x65. the knives are two cold steel kitchen knives, one henckels, one forschner. i was able to raise a burr on one side of the victorinox boning knife. the rest of the knives and other side of the forschner, nothing. it didn't even start to raise nearer the handle as they sometimes do. is this user error or is this thing garbage? not hitting the apex? i'm obviously taking material off the knife, using the p120 belt from medium to high, it should raise a burr fairly quickly, after 10+ passes, there is exactly zero burr. i'm at my wits end with this sharpener.
 
chado skins said:
i took four knives to the KOWS today. all of them being on a dull side. of the eight sides, i could raise exactly one burr. i tried both the P120 extra corase belt and x65. the knives are two cold steel kitchen knives, one henckels, one forschner. i was able to raise a burr on one side of the victorinox boning knife. the rest of the knives and other side of the forschner, nothing. it didn't even start to raise nearer the handle as they sometimes do. is this user error or is this thing garbage? not hitting the apex? i'm obviously taking material off the knife, using the p120 belt from medium to high, it should raise a burr fairly quickly, after 10+ passes, there is exactly zero burr. i'm at my wits end with this sharpener.
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I don't think it's you or the sharpener... just a question of getting everything in sync... especially the first sharpening of a knife with a new method or device. Didn't read thru the entire thread, so sorry if already suggested... but mark both sides with a sharpie and see where you're removing metal (or look under magnification). It may take more then 10 passes to reach the very edge... especially if you're changing the angle of the bevel.
 
Have you used a sharpie on the edge to see if you are actually reaching the apex? Depending on the original edge angle and what angle you are trying to sharpen to it may take many more than 10 passes to reach the apex and form a burr.

The WSKO may be faster than other methods, but if you are removing a lot of steel from the shoulders it's going to take awhile, possibly much longer than you might think.
 
i've messed with all of these knives on this sharpener before, so it's not really their "first" time. i'll try the sharpie method to see where and if i'm taking material off. thx for the replies :)
 
it took the sharpie marks right off. right to the edge. i marked the previous bevel i had put on the knife, and it's all gone. it raised a very faint burr, almost at the tip and nowhere else on the edge. how is that possible to remove all that material and not raise a burr? i continued to the other side with the same results, sharpie gone, no burr. the edge feels a little better, but it's not terribly sharp.
 
That the edge is "getting better" seems to indicate that you still might not have completely apexed the edge. Do you by chance have a decent magnifier you can look and see what's going on right at the very edge? The belt my be hitting just enough to erase the mark, but still not quite there. Also, if you're alternating sides, you won't feel much of a burr.

If you're confident you're hitting the very edge, try progressing thru the rest of the belts (sharpie and look as you go thru each belt and do alternate sides), and see what the end result is.
 
no magnifier. with this run i was trying to raise a burr, so i wasn't alternating. it was all one side. i went ahead and progressed through the belts, sorry i didn't post that i did that. i can see that maybe the belt is taking off the sharpie, but that doesn't necessarily mean it's taking off a lot of material... i shouldln't have assumed that. the sharpie test is just to see where the abrasive is making contact... which it seems to be doing. this thing feels like it's more trouble than it's worth... shit.
 
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