Sharpening/Thinning Clad Knives...Am I Just Being Dumb?

jpm2 said:
Thanks for not minding.

Back to the subject, the only laminated blades I have are the Spydercos Diemaker mentions, and an older mora.
Haven't used or sharpened the mora much, but the Spydercos have been thinned, sharpened, and reshaped a lot.
I've used diamond plates, diamond bonds, Norton crysolons and their aluminum oxide stones, cheap ace hardware aluminum oxides, and spyderco sintered ceramic without any issues, other than aluminum oxide not cutting very well.

I guess I don't really understand the concern, is there something different between other makers laminated steels and Spydercos when it comes to type of abrasives used?
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I believe the cause for concern over abrasive type is probably derived chiefly from Japanese laminated culinary knives, which are often run in a glassy-brittle hardness range at very low angles, which makes them very sensitive to lateral pressure, and can result in chipping if excessive pressure occurs as a side load, as it may when sharpening.
 
J jpm2 I'm not at all sure about an actual difference.

My perceived concern was/is that whatever the outer core on the Japanese knives that it was used with the idea that Japanese water stones would be used to maintain it. Meaning they expected a certain type of slurry, grit size. etc. Now, that might be silly for a couple reasons on my part but that has always been my concern.

The there is the hard steel core. I can finish sharpen (hone) Spyderco's VG10 on my Arkansas for example but I don't know how it would do on the higher HRC stuff the Japanese makers usually run it to. I can sharpen BD1N at 61+ on Arkansas just fine but high HRC VG10? Don't know.

These knives also often have such low angles and/or single or asymmetric grinds to further complicate the issue.
 
FortyTwoBlades said:
I believe the cause for concern over abrasive type is probably derived chiefly from Japanese laminated culinary knives, which are often run in a glassy-brittle hardness range at very low angles, which makes them very sensitive to lateral pressure, and can result in chipping if excessive pressure occurs as a side load, as it may when sharpening.
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Was typing when you posted.

That and, I had a concern about just scratching the heck out of the outer cladding but not really being effective at revealing the inner core without just leaving an unstable edge. Whenever I've watched a Japanese chef or sharpener do that work it has always been on water stones. I have zero experience with water stones and only know what I read and see. Right or wrong, in my mind I was thinking the knives and stones went sort of hand-in-hand. That seems to be the way the Japanese approach things.

I hop e that makes sense...
 
Eli Chaps said:
Was typing when you posted.

That and, I had a concern about just scratching the heck out of the outer cladding but not really being effective at revealing the inner core without just leaving an unstable edge. Whenever I've watched a Japanese chef or sharpener do that work it has always been on water stones. I have zero experience with water stones and only know what I read and see. Right or wrong, in my mind I was thinking the knives and stones went sort of hand-in-hand. That seems to be the way the Japanese approach things.

I hop e that makes sense...
Click to expand...

Synthetic vitrified bond stones in fine grit ranges are naturally soft due to the way that the manufacturing method works, which makes water an optimum choice for lubrication for such a stone. Urea-formaldehyde bond stones ("splash and go" stones) are very hard but water softens and breaks down the binder, which is why you don't soak them (they'd dissolve away to nothing). So those are the two major flavors of synthetic water stones. Water stones, by way of their rapid breakdown, tend to provide a certain amount of "cushion" to the blade, which does spread out the point-pressure on the apex a bit. It's not strictly necessary, though, so long as you're aware of how the stones you have perform and what the blade in question is able to handle. :)
 
Do note that different steels exhibit different behaviors at different hardnesses/heat treatments. A lot of the Japanese culinary knives that are chipping-prone are done in what are basically low-alloy carbon steels run at high hardness, and those steels are pretty delicate in those ranges. Many of the more complex steels are able to maintain a higher toughness at the upper end of the hardness range. VG-10 tends not to be so chippy as high-hardness blue steel, white steel, or SK-5, which are all commonly seen in laminated culinary knives.
 
I've literally sharpened tens of thousands of Japanese kitchen knives and the blades are not that hard. VG-10 @ an actual 61-63 is going to be very expensive and from a limited number of makers. For example: if you are spending less than $300 you are probably not getting the hardness you hoped for.

Realistically, most will be closer to 59-60 and this goes for a wide range of steels. Japanese makers usually push the hardness of Blue or White steel and more often with traditional blades like the Yanagi or Deba. Even then its only to 61-62 unless again, you are dishing out the cash and selecting a specific maker that specializes in said steel which you then might experience 64-65 HRc. At this point you better have some good stones too, ya gonna need them.

Where Japanese knives really shine is in their cutting geometry. While you can still have some that are a bit thick most J-knives have very good blade geometries and this provides excellent cutting performance.

Not trying to take away from any of the greatness that is Japanese cutlery but a lot of hype often gets mistaken for fact in this genre of knives.
 
Thanks Jason B. Jason B.

You're obviously right. I just went back through my knife "wish list" and realized that many of the VG-10 offerings didn't even have an HRC listed. Reckon I was starting to roll everything together in my mind. Sometimes, too much searching at once can be a bad thing! :)
 
Yep, just dug back through and found the one VG-10 core knife I was really interested in and it is listed as 60HRC.
 
I wouldn’t be inclined to sharpen a VG-10 knife (stainless steel) on a Arkansas stone as the Chrome Carbides are harder than the micro crystalline quartz. Al203 will do Cr and Mo Carbides. SiC will do those and Nb and W Carbides. Diamond is needed for V and Ti Carbides. Even though SiC was developed for sharpening W (Tungsten) Carbide, some charts show that WC is harder than SiC.
High hardness alloys like ZDP-189 (67 HRC) can be sharpened on Al2O3.
Cr=Chrome
Mo=Molybdenum. Correction: Even though SiC is RECOMMENDED for sharpening
WC, some charts show...........
Nb=Niobium
W=Tungsten (Wolfram)
Ti=Titanium
V=Vanadium
 
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tiguy7 said:
I wouldn’t be inclined to sharpen a VG-10 knife (stainless steel) on a Arkansas stone as the Chrome Carbides are harder than the micro crystalline quartz. Al203 will do Cr and Mo Carbides. SiC will do those and Nb and W Carbides. Diamond is needed for V and Ti Carbides. Even though SiC was developed for sharpening W (Tungsten) Carbide, some charts show that WC is harder than SiC.
High hardness alloys like ZDP-189 (67 HRC) can be sharpened on Al2O3.
Cr=Chrome
Mo=Molybdenum
Nb=Niobium
W=Tungsten (Wolfram)
Ti=Titanium
V=Vanadium
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Just gotta' chime in hear to note that the bolded statement above is false. Acheson invented SiC by accident during a failed attempt to create diamond by electrically fusing carbon. Upon recognizing the potential usefulness for the material, he scaled up the production method and the rest is history. :)
 
FortyTwoBlades said:
Just gotta' chime in hear to note that the bolded statement above is false. Acheson invented SiC by accident during a failed attempt to create diamond by electrically fusing carbon. Upon recognizing the potential usefulness for the material, he scaled up the production method and the rest is history. :)
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Thanks, I like facts in sharpening threads, and that was a famous "chance" discovery.

Russ
 
Thank you for the correction. It was many years ago that I came across the information. Probably what I read was that the use of Carborundum was adapted to the sharpening of Tungsten Carbide tools which were a little hard for Corundum. Tungsten Carbide cutting tools were not used until about 25 years after Silicon Carbide was fabricated.
My memory is as good as it used to be, but it is not as long.
 
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It's honestly kind of incredible that such a revolutionary material was invented via what was ultimately such a primitive experiment.
 
Incredible indeed, just look to things such as penicillin and Teflon, one invented because Flemming forgot to tidy away his lab equipment away and the other because a US chemist noticed an old can of tetrafluoroethylene felt heavier than it should of.

And to think people say that science just for sciences sake isn’t useful...
 
I work at a major university which does a lot of research. My department exists solely to help research happen. In my view, scientific research is a very different prospect than most types of business. It is "the R&D of the world". R&D doesn't always yield useful results. But those few times... those lightbulb moments... those one in a million occurrences. They can change the world. I hope for a few of those to happen with the research groups that I support.

Brian.
 
bgentry said:
I work at a major university which does a lot of research. My department exists solely to help research happen. In my view, scientific research is a very different prospect than most types of business. It is "the R&D of the world". R&D doesn't always yield useful results. But those few times... those lightbulb moments... those one in a million occurrences. They can change the world. I hope for a few of those to happen with the research groups that I support.

Brian.
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I'm work in R&D in a very specialized metal field. Love it!
 
My wife loves her VG-10 Shuns and if they are on the soft side they sure are chippy. I have always sharpened them on Arks, no problem at all(for a bunch of years). I thought VG10 was usually run around 60-62?
My stones aren't any good and neither are my knifes. Seen the same thing happen to my rifles. ;)
 
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