Sharpmaker - Kershaw "Needs Work" Help - get to hair popping

[STR]

Oh yeah. One more thing to think about before I forget. Regarding thinning the edge down. I've done this and on some steels at some hardnesses it works fine. On others, well, it works and while it may be true you can bring the knife to a greater, even easier initial sharpness the frequency of sharpening may increase because you might notice after that the thicker edge did in fact stay sharp longer.

Many folks use those knives just the way they are from the factory and find they work fine that way for the everyday grind. If you are not that good at sharpening or if its a pain to do except for once in a while it might be best to leave well enough alone and speaking of that. It goes without saying that one of the secrets to sharpening is knowing when to leave well enough alone. Oversharpening happens more often than sharpening in other words because people don't know when to stop.

STR

 

[Cliff Stamp]

But all I have to work with is the Sharpmaker.

You can buy a cheap stone at a hardware store for $2 which will be much faster for changing angles. If you are seriously interested in maximizing the ability of your knives then you should really invest in one.

Could I somehow use the 30 degree setting and then the 40?

Yes, it will take awhile to reduce the angle though on the Sharpmaker, like an hour or so.

Could it possibly be dexter causing the burr (no offense dexter)?

Properly hardened, that steel is designed to not form deformation burrs. I do not even use burr removal or minimization techniques on that class of steel when I sharpen them. The techniques I noted in the above to minimize burrs should not be necessary on 13C26. If they are then there is an issue with the steel.

How do you explain the lack of consistent complaints about burr's?

Lack of consistent heat treatment / production sharpening.

i havent found a knife yet, other than pakistan junk that i couldnt sharpen.

Have you worked with ceramic blades?

To be precise, it seems Cliff didn't discredit the steel ...

I have been advocating low carbide and high hardness steels for thin edges with high polishes for about ten years. This is not a new area of discussion nor something that centers around Kershaw. What I have pointed out in their use of the steel specifically was that given the geometry and hardness they are using, they would be better off with 12C27M as it is tougher, easier to grind, more corrosion resistant and cheaper. Though as an aside, given the thick/obtuse edges, you might as well use a high carbide steel anyway because the geometry is inherently stable, so use 440C or similar.

12C27M is a superior rough use knife steel, 13C26 is designed to excel in very thin edged knives, < 0.010":10 degrees. This arguement is also not specific to those steels but deals with general class properties. The same would be said for example with 1095 at 58/59 HRC, the S series steels, or simply 1055 at that hardness would be a more optimal choice for much the same reasons, aside from the corrosion resistance issue.

As a general rule, you are always better off switching steels than underhardening a steel. When you underharden you tend to lose corrosion resistance, aggregate carbides, enlarge the grain structure, basically make everything worse. You will get much better properties with a steel designed to run at that hardness. You can see the spec sheets for the Sandvik steels on the blade materials page on the website.

Hopefully Spyderco will put out a series of blades in those steels, 12C27M and 13C26 and really show the optimal performance. They would make a nice bushcraft pair, small parang (maybe hatchet) and precision whittler. They would also be a nice set of test materials for the mules they are preparing, if so they could include 19C27 as well. Those would make an interesting set to work with.

-Cliff

 

[dextersp1]

dextersp1, if you live in the usa, send me your phone number and i'll call you this weekend and help you out with getting your knife sharpened. i havent found a knife yet, other than pakistan junk that i couldnt sharpen. i have used or seen just about every contraption out there but i use a set of cardboard wheels since they do a better job than anything i have used or seen. one important thing other than having the right angle is working up a good burr the full length of the blade, one that you can see and feel. once you have a burr worked up the next thing you want to do is remove the burr and polish the edge while retaining the angle. i hope this little bit helps.

Richard,
Thanks for the offer - I live in Smyrna, Ga. I want to learn how to sharpen a knife properly on the Sharpmaker and the "Needs Work" and then buy other knives I am interested in.

Question - is there a way to test for a burr? I think I saw it.

I think I did have a burr on the knife. After taking Cliff's advise I did notice a lot of steel coming off the knife. His advise did help smooth things out - newspaper cutting and arm hair cutting. My arms are looking a bit strange right now. But I think the knife is not as sharp as it could be. I want to used it for hiking/camping sharp.

This is my second "Needs Work" The first one was hair popping sharp out of the box. I had to send it back because the assisting opening broke. The one they sent me back had a rougher edge and could get hair off my arm by scraping.

I'm sure after I get through this I will look back and understand the process and see it as obvious.

 

[STR]

Cheap stones are also problematic in regards to burrs, so a better stone is nicer to sharpen with, especially on very hard to grind steels.

-Cliff

Originally posted by Cliff Stamp:
I noted in the above to minimize burrs should not be necessary on 13C26. If they are then there is an issue with the steel.

I don't know about you but I see burrs form in all steels I sharpen but not all blades as they are as individual as we are as people. To say one steel forms this over that is a bit problematic in my experience because it doesn't really pan out that way. I can think of two blades in my own collection that are both the same steel and one forms a burr readily the other hardly ever and yet both are from the same company made the same month, and of the same steel and hardness level and for that matter both have near identical profiles and primary grinds as well as 15` bevel angles. Go figure.

STR

 

[Cliff Stamp]

I can think of two blades in my own collection that are both the same steel and one forms a burr readily the other hardly ever and yet both are from the same company made the same month, and of the same steel and hardness level and for that matter both have near identical profiles and primary grinds as well as 15` bevel angles.

The same hardness does not imply the same heat treatment. Burr formation is a matter of aus-grain, carbide volume and hardness. It is a property of steels just like corrosion resistance, because there is variability does not negate that. Not all pieces of 440C have exactly the same corrosion resistence but this does not mean you can not talk about the corrosion resistance of steel as a property of the material.

Question - is there a way to test for a burr? I think I saw it.

Use a light, tilt the edge a little looking at the blade from the side, you will see a shadow until the folded over edge. if you do this for awhile you will be able to spot burrs quickly. A small magnifier, 10-20X is easier to start with though. Radio Shack sells a small hand held microscope that I commonly use, was $10.

-Cliff

 

[richard j]

dextersp1, like i said earlier, i would be able to help you out better by talking with you over the phone. as for the kershaw knives, there is nothing wrong with them. i have sharpened many kershaw knives over the years and the owners just love them. as for burrs, i agree with str on that matter. i have several custom made knives that wont form a burr or much of a burr that is visible without help. the method i have for detecting a burr is hard to explain in writing but its always worked for me. it takes time to get good at sharpening, i have been at it for a long time and it only takes me minutes to sharpen a knife.

 

[thombrogan]

Dextersp1,

Please clean off your Sharpmaker rods before proceding. All of this sharpening has probably loaded them up with steel (looks silvery on the browns and blackish on the whites). After that, if you have a good marker like a Sharpie, please coat both sides of your knife's edge and let the ink get nice and dry. Place the brown hones in the 30 degree setting of the Sharpmaker so that the corners face the edge. Get some free time - you'll need it.

The Back-Bevel setting:
Keeping the edge pointing straight down, sharpen on the corners of the brown stones at 30 degrees until all of the ink has been removed from both sides. During this one step, you can use muscle as this will not be the actual edge. As the corners load up with steel and look all silvery, flip them. Each stone has three corners, so get your money's worth out of them. You only have to do this once in a long while, thankfully.

For the edge itself, the flats are the way to go. Those corners add force which is good for hogging off steel (as it's a bit slow, maybe groundhogging?), but they often make it easier to use too much force when sharpening the actual edge (necessary evil on your serrated and heavily curved blades). Anyways, clean off the rods and place the brown ones in the 40 degree setting with the flats facing your knife's edge. Wrap a rubber band around them near the base (a tip stolen from the great folks at the Spyderco.com forum) so that its actual angle is less than 40 and more than 30 degrees. Make 20 light, alternating strokes with your edge at that setting. Make about 12 more VERY LIGHT alternating strokes at that same setting. Undo the rubber band, clean the brown rods then and there if desired and wash and wipe you blade clean. It will have picked up loose steel from sharpening which won't help you when you go to the next step. The next step is to use the white rods at the 40 degree setting with the flats facing the knife's edge and no rubber bands. Repeat the same steps as you did with the flat parts of the brown rods and remember that you can never go too slow or too light.

The reason for the rubber band and lower angle on the brown rods is that the variances in production can make it so that they might sit at 40 or 42 degrees and the white rods might sit at 39 degrees. With mass-produced ceramics and plastics, that sort of thing can happen. So instead of calling foul and ripping a new one into the manufacturer, we find tricks to let us move on keep up the facade that we are grown ups.

======================================

Cliff,

I intentionally burr each and every steel I sharpen and if I raise a burr on 13C26 tempered down to RC61 or 57 or 900, it's highly intentional. I do it on 420J2 and on YSS Aogami Super - it's part of how I sharpen. I burr every steel I sharpen and I dent and chip every steel I use at some point. It would be wrong to do otherwise. It's steel and must be burred by my stones and chipped by my errors.

Kershaw's 13C26 takes angles I like (below 30 included degrees edges) and doesn't chip when I whittle hardwood (ZDP-189 and SG-2 are the only high carbide steels which show similar love). And when I overdo it and sharpen at too thin of an angle (my poor External Toggle!), it just rolls instead of rolls and severely cracks like my other favorite folder steels.

I'm doing the potty-dance with wild-eyed hopes to get my hands on a santoku made by Larrin Thomas which will feature AEB-L hardened to RC63 with a complicated temper to eliminate retained austenite and when that needs to be sharpened, I'll raise a burr on that RC63 AEB-L edge, too. It's not the steel's fault that I'm a fan of Larrin's grinder skills.

 

[thombrogan]

Dextersp1,

If you're over 21, I'll gladly resharpen your Needs Work folder using just those tools and the method described for you. If that'd work, please send an email to brogan3 at comcast dot net

 

[Cliff Stamp]

The reason for the rubber band and lower angle on the brown rods is that the variances in production can make it so that they might sit at 40 or 42 degrees and the white rods might sit at 39 degrees.

That is an interesting tip, have not noticed that with the couple I have used, they produce identical microbevels, but variances do happen.

I intentionally burr each and every steel I sharpen ...

Depending on how you define it, Verhoeven defines a burr as just the non-zero edge width, from his viewpoint there is always a burr. I define it as the extent of non-abrasive formation, so it is either deformation/fracture based, usually deformation unless the heat treatment was really off.

You even burr the 1095/M2 blades at 65/66 HRC? Mine don't even burr and I do not even try any burr minimization or removal techniques. Comparing the ability of those steels to burr versus the ultra soft stainless certainly shows extremes in behavior.

...ZDP-189 and SG-2 are the only high carbide steels which show similar ...

It is relatively interesting ZDP-189 does as the carbide volume is so high, makes a strong statement on the influence of even small changes in hardness, unless you are speaking of customs vs the production 63 HRC blades.

So AUS-8A at 58 HRC and the Byrd steel tend to chip as well at low angles? Have you compared the Byrd steel at 60/61 HRC vs 13C26 at 57 HRC?

-Cliff

 

[STR]

I've found that cleaning off the rods of any ceramic is easiest done with one of the cheap rust erasers you can find from places like Smokey Mountain knife works. The thing lasts and lasts and lasts too.

STR

 

[matt321]

I tested the angle difference between the brown and white rods on my SharpMaker with a t-bevel. My white rods stand about one degree nearer vertical than the browns. (If I lay a brown rod and a white rod end-to-end on a flat surface, the white rods are thicker. That must be why they stand taller in the slots.)

So my white rods are hitting behind the edge set by the browns. Due to the freehand inaccuracy, the actual strokes must vary by several degrees so that the system still works, but half the white strokes don't accomplish anything!!! Bummer.

 

[samhain73]

I clean off the Sharpmaker stones with an ordinary pencil eraser.

 

[Cliff Stamp]

Well the whites at least will then polish the shoulders above the bevel, a lot of makers argue that is really important for performance.

-Cliff

 

[thombrogan]

That is an interesting tip, have not noticed that with the couple I have used, they produce identical microbevels, but variances do happen.

Never would have thought of the variation nor the solution on my own. The variation was mentioned by Jeff Clark and I believe our beloved Dr. Hannibal Lecter shared the solution at the Spyderco.com forum.

You even burr the 1095/M2 blades at 65/66 HRC? Mine don't even burr and I do not even try any burr minimization or removal techniques. Comparing the ability of those steels to burr versus the ultra soft stainless certainly shows extremes in behavior.

The half of the edge facing the abrasive curls up towards the half not touching the abrasive. On the harder steels, regardless of carbide volume, the burr is smaller than on the softer steels, but there it is. In the finish levels below 7 microns (2000 grit and higher), it's more easily felt with my thumbnail than the pad on my thumb (thanks for the tip, Knifeoutlet!).

It is relatively interesting ZDP-189 does as the carbide volume is so high, makes a strong statement on the influence of even small changes in hardness, unless you are speaking of customs vs the production 63 HRC blades.

Prodiddilyuction, hombre. Spyderco.

So AUS-8A at 58 HRC and the Byrd steel tend to chip as well at low angles? Have you compared the Byrd steel at 60/61 HRC vs 13C26 at 57 HRC?

I've chipped and dented AUS-8A at wherever Cold Steel and Spyderco were running it, but I've never used 8C13CRVMoPhillips - only sharpened up a Cara Cara for a pal with a booboo.

Well the whites at least will then polish the shoulders above the bevel, a lot of makers argue that is really important for performance.

I always bought the argument that behind the edge was irrelevant and yet my knives with polished back-bevels/reliefs cut with less friction for longer periods of time than ones where I left a coarse-finished relief.

 

[Andrew Taylor]

Dexter

Send me an e-mail with your address and I will send you an inexpensive, three lens magnifier. You can use 1, 2, or all three lenses for increasing strengths of magnification. They only cost 2 bucks from Princess Auto, so my treat.

Using strong magnification will show you where your sharpening is going wrong and help you appreciate the quality of the steel in the knife from Kershaw. Hold the knife in a good strong light and use the magnifier to slowly scan the cutting edge on both sides and direct on to the edge. I guarantee that you will see the reason your edge isn't as sharp as you would like.

 

[offsetlover]

i think that is interesting to note, though i have not gone through every post, that when Cliff says something bad about a steel, Kershaw is somehow involved. at least thats what i have seen recently (like the time i have been a member here on the forums). just my 2 cents

 

[shecky]

i think that is interesting to note, though i have not gone through every post, that when Cliff says something bad about a steel, Kershaw is somehow involved.

I think it'd be more interesting to note in Cliff's posts why Kershaw is involved.

 

[richard j]

what does my ability to sharpen a "ceramic knife" have to do with sharpening a "steel knife"? NONE!!!! i'm trying to help someone with a sharpening problem, not attack someone's abilities in order to draw attention away from their attacking kershaw steel.

 

[Cliff Stamp]

i think that is interesting to note, though i have not gone through every post, that when Cliff says something bad about a steel, Kershaw is somehow involved.

If you look at the posts where I discuss a steel being used by Kershaw then it is very likely that Kershaws use of the steel will indeed be described.

I think it'd be more interesting to note in Cliff's posts why Kershaw is involved.

I would indeed suggest to forget about the manufacturer, and even about the specific steels, and consider instead what is being said about the properties of the steels and what is it about the steels that makes them that way. Why would 12C27M be a more optimal knife steel for a blade at ~59 HRC than 13C26? If the edges are 0.030"/25 degrees then why is 154CM a better knife steel than 13C26? These questions are much more valuable to think about if you want to understand steels than whatever Kershaw is doing with their knives.

On the harder steels, regardless of carbide volume, the burr is smaller than on the softer steels, but there it is.

You have not found it to be dependent on carbide volume?

I've chipped and dented AUS-8A at wherever Cold Steel and Spyderco were running it, but I've never used 8C13CRVMoPhillips - only sharpened up a Cara Cara for a pal with a booboo.

AUS-8A and 8C13CrMoV are similar class steels to 13C26 in that they are low carbide, ASU-8A has a maximum hardness of 62/63 and 8C13CrMoV of 64/65, but this requires oil+cold and a minimal temper. Benchmades 60 HRC AUS-8A and Spyderco's 61 HRC 8C13CrMoV should give fairly high stability edges. It would be interesting if they were less so than 13C26 at ~57 HRC.

I always bought the argument that behind the edge was irrelevant and yet my knives with polished back-bevels/reliefs cut with less friction for longer periods of time than ones where I left a coarse-finished relief.

I have not noticed any difference in use, the friction will only be noticable if the abrasives scratches are significantly non-parallel to the cutting motion and the media is not significantly wedging. Even in this case, by definition the frictional force can only be a small (few percent) of the total wedging force, unless you are cutting something which is very adhesive like tar backed shingles. But at a minimum, just consider all those "wasted" strokes as offering to the sharpening gods anyway.

-Cliff

 

[dextersp1]

Thanks for all the advise - I'm going to get a magnifiying glass and keep at it.