Need advice on reprofiling bevel

[tjkoko]

I want to reprofile the edge/bevel on my old French carbon steel chef's knife. Which of the two stones listed below would be recommended and please explain the difference in usage between the two.

Tri-Angle Stones Cubic Boron Nitride
Tri-Angle Stones Diamond

[sal]

Hi Tjkoko,

Welcome to our forum.

We make both diamonds and CBN stones because we are also comparing the two. They, in my opinion, seem to cut fairly similar, though I'm leaning to the CBN. They both last longer if you don't press too hard. Very little pressure is required to reach maximum cutting. I believe the CBN will last longer, but we're still involved in real world testing.

sal

[tjkoko]

Hi Sal and love the Spyderco sharpener. Concerning the two stones addressed in my OP, do I understand them to be as aggressive as a coarse silicon carbide stone on my Norton Tri Hone?

And allow me to state that I also possess a black surgical bench stone and I've NEVER EVER achieved the razor sharpness usng it compared to what I've achieved using Spyderco's stones. I kiss noone's beehind but these ceramic stones of yours are the utter bomb! 8)))

[Pelagic]

I would say diamond, since generally speaking, it cuts faster than CBN, and as much as I enjoy it, I prefer to minimize time spent sharpening. But all products are different. Certain CBN products may cut faster and leave a much more uniform scratch pattern than several diamond products.

It depends on how far you want to go with the edge. If you want to go well over 1000 grit, as I hinted at before, I'd go with whatever cuts faster, because in the end you will have nullified the scratch pattern (and possible small gouges) left by your first stone. If you plan on using only 1 more stone after re-profiling, I'd suggest re-profiling with whichever product yields the most uniform scratch pattern. With a chef's knife you probably don't want a jagged (I use this word comparatively speaking) edge.

[JD Spydo]

First off I want to say that I'm a long time, very avid fan of the 204 Sharpmaker. I got my first one way back in the late 90s when they were first released and I had also owned a 203 unit even before the 204 unit was ever released. So with all that being said my history of Spyderco's great sharpening tools and I both go back a few years. But for me I've kind of abandoned the Sharpmaker for "reprofiling">> well at least for now anyway until they get some type of really coarse/aggressive stone for quick stock removal.

What I do before I finish with the Sharpmaker is to do most of my reprofiling with one of my diamond benchstones. I've got two really aggressive stones>> one is a 3M extra-coarse grit and the other is a Norton Coarse. I find both of them to remove metal at a far faster rate than I've been able to do with the Sharpmaker unit. The 204 Sharpmaker is what I mainly use to do finish work with. And this is coming from a big, long time fan of the 204 Sharpmaker. I've yet to get a set of the CBN stones and I'll admit that I've been dragging my heels on that one but I will get a set soon and let you all know if they work any better than the diamond rods that come with the 204 Sharpmaker. But those diamond 204 stones just are not coarse enough for me.

[awa54]

If you already use bench stones, I'd suggest getting a medium diamond plate in a large enough size (I like 8"x3" for large blades) and then the Spyderco medium and fine bench stones.

...although I still free hand my kitchen knives on water stones, since they're more fun to use and cut old school carbon and low carbide stainless steels just fine.

[setldown]

If you have a Norton Tri Hone and feel comfortable using that, do the heaving lifting with that and finish up on the Sharpmaker.

[tjkoko]

All replies are well taken and I guess I'll continue using my Tri Hone for coarse metal removal and reprofiling rather than get a whole new stone. The coarse carbide sounds fine with me.

[Fixmeister]

My only experience with CBN is on my Tormek grinder. I have a 600 grit stone and it is an amazing tool. I prefer the way it feels as it cuts compared to the diamond stones on my Wicked Edge. Not exactly apples to apples, but...

Personally, I’d rather have CBN as long as it’s properly bonded to the base metal. There are reported rumors of the CBN not adhering as well as diamond. CBN is a metal and it’s configuration is square (cubic) so there are corners available to cut. And it transfers heat from the cut to the base. Probably not an issue with hand sharpening but still a good thing.

[Bodog]

For reference I understand that spyderco uses synthetic monocrystalline diamonds for their rods. Please correct me if I'm wrong.

Here's a several year old thread with a lot of pertinent information about the topic

//forum.spyderco.com/viewto ... &hilit=Cbn

Most relevant statements based on sourced data:

In a nutshell monocrystalline or natural diamonds are better for bench stone type applications because the wear rate is lower (wearing the stone in), unless you want to retain higher abrasive properties (fast cutting rates) longer. If you want to retain higher abrasive rates in a bench stone, then polycrystalline diamonds are the best because they crystals break down giving repeated and continuous fresh abrasive while also leaving a more uniform scratch pattern than monocrystalline diamonds. But since the bond that makes the polycrystalline structure breaks down, the stone with polycrystalline diamonds won't last quite as long but it will perform better, longer. CBN is very close to replicating the performance of polycrystalline diamonds in low heat environments in a bench stone type application.

For pastes and fluids polycrystalline diamonds are the best but CBN, which is also polycrystalline, is just about as good while being cheaper to produce. Whether that is seen at retail, I don't know. CBN is better than polycrystalline diamonds at high heat but in knife sharpening applications the point is moot. CBN, in fluids or pastes, is better all around than monocrystalline diamonds, is more expensive to produce, and gives better results much longer. Monocrystalline diamonds' points and edges wear down leading to lower cutting rates much faster than either polycrystalline diamonds or CBN. Since applications requiring diamond or CBN paste or fluid don't normally see use extending for years, then polycrystalline diamonds show the best performance for the high hardness demands while CBN shows performance that rivals polycrystalline diamonds at hardnesses common in hardened knife steels while CBN's performance jumps ahead during high hear applications, again, a moot point.

Monocrystalline diamonds should be left out of fluids and pastes altogether unless you need good performance for much lower costs than can be found with either polycrystalline diamonds or CBN. For knife sharpening bench stones, monocrystalline diamonds give the most extended wear but the performance tapers as the edges wear down. Polycrystalline diamonds and CBN in bench stone form give almost identical performance for knife sharpening applications with CBN being cheaper to produce. Both polycrystalline diamonds and CBN give a higher level of abrasive performance longer than monocrystalline diamonds.

Again, what's seen in the marketplace may or may not reflect production cost."

And (hyperlinks don't work here on the copy and paste but if you click on the thread hyperlink and go to page 2 they work):


I'm going to post some links from a quick search. There is far more on the topic that anyone can feel free to look up on their own.

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https://books.google.com/books?id=9O6r7 ... eturnfalse;.


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https://books.google.com/books?id=zs_lG ... nd&f=false" onclick="window.open(this.href);return false;