Chosera stone maintenance

[Mark76]

Thanks Tom! What you write makes perfect sense to me. I’ve asked Ken (Schwartz, sorry KenBuzBee 😉 ) to react here as well, since he seems to have a contradictory opinion.

As I wrote Phil, opinions are fine 🙂 but by confronting contradicting opinions, we can perhaps squeeze out facts.

I am pretty sure you will not satisfy your quest for understanding by asking for opinions..
Especially when, as we have seen, the experts either don’t agree, or don’t care.

I don’t have the level of experience with the Chosera stones that Ken and Tom have – those guys have been at it for a long time. I like the idea of setting up an experiment, should be easy enough to do if one has the time, I’ve been short on that lately… Once we get into our new space and I can set up a better R&D area, I can do more experimenting again. I’ve been consumed with design and production for the last 6 months.[/quote]

That would be great, Clay. As I wrote before, I have already carried out the experiment. With 5K and 10K Choseras and 15K Shaptons.

The problem is that these stones cause very tiny scratches. And my VEHO microscope cannot differentiate between (for example) the scratches made by a 10K Chosera lapped with an Atoma 140 and a 10K Chosera lapped with a 1K WE diamond stone. I guess we really need your microscope or a SEM…

Molecule Polishing: my blog about sharpening with the Wicked Edge

[Ken Buzbee]

I’ve asked Ken (Schwartz, sorry KenBuzBee 😉 )

No worries, Mark. I know who the “Alpha Ken” is around here 😉 I’m just one of the pack 😉

the other Ken

[Mark76]

I’ve asked Ken (Schwartz, sorry KenBuzBee 😉 )

No worries, Mark. I know who the “Alpha Ken” is around here ;)[/quote]

😀 😀 He’d better respond then!

Molecule Polishing: my blog about sharpening with the Wicked Edge

[Phil Pasteur]

Or maybe not
🙁

[Ken Schwartz]

So for starters, let me repost what I said ‘over there’:

I would split this into flattening and texturizing. Even a very fine stone needs to be flat and if it isn’t it’s a waste of time to just use a fine plate. Now if it is a little off, well then a finer plate is a good thing.

I haven’t read Tom’s posts there (and should) but somehow transferring stone scratches to knife edge scratches doesn’t sound right – even from Tom 🙂 (We quibble all the time about sharpening theory.) It doesn’t match my experience at all. Now if we are talking about jagged edges on a natural then yea these can scratch up a finish.

Finer diamonds make for finer surface textures. Here a 400 600 or even 1200 Atoma slurry slurry stone makes a difference. You can see this on new stones which have a factory finish. After use the surface gets more refined and it feels nicer to sharpen on it. On the other end coarse stones benefit in aggressiveness from a coarse texturizing. So a 24 grit Aratae Nubatama will give a rough surface to a 220 Glassstone, improving it’s performance for instance.

Personally I sharpen and I like to enjoy sharpening as a process, not just the result. And a well texturized stone is less ‘fugly’ and more sensual, so I make the surface nice to work on – once it is flat. I also rub stones together for this, so if I have a piece of stone like a 15k shapton chip, I’ll rub it on my 15k Shapton to make it nicer to use.

—
Ken

So I since had a chat with Tom and it seems we are in agreement on the topic. I don’t think either of us meant to say that the scratch pattern on the stone translates to the scratch pattern on the steel, but a more aggressive surface texture on coarser stones cuts more aggressively and vica versa. Not really a different finish.

I’d also add that after doing a couple of knives the surface smooths out as one abrades through the stone below the coarse scratch pattern.

With the WEPS, you do have the relatively unique situation of having two stones of the same grit to work with, so texturizing one with the other gives you a near ideal surface texturing.

While I do respect Sal (of Spyderco) somehow the idea that two stones of different coarseness are only differing on surface texture seems off – Perhaps a misquote or carelessly worded statement. Don’t know for sure. I’ve heard and seen this idea on the Tormek setup, but this is certainly not a way I would use stones based on JUST the scratch pattern.

Hope this helps.

—
Ken

[Phil Pasteur]

Well.. it seems that we have a general agreement…

I am not sure where the scratch transferring thing started. My thought was that the coarser texture on any given stone will act differently at the edge. No more!

Ahhhh.. feels good … agreement. Will make Mark happy too.

BTW, that quote from Sal was from a post he made himself on the subject… at least posted under his name.

[Ken Schwartz]

“can scratches on a stone transfer to the edge. It seems you say “yes” and Ken says “no”.”

The word ‘transfer’ may be the culprit here. If you are saying that the scratch pattern of the stone from the diamond lapping Transfers to the knife I would disagree – these are two different things. If you are saying that it influences it, that might be another topic worth investigating further. Now, to get a bit esoteric, if you are invoking ‘transfer’ in the sense of a transfer function in mathematics you might run into in signal processing mathematics and digital filtration theory, ie transfer functions, well this becomes a much more interesting subject 🙂

Of course this opens up the discussion to not just diamond lapping plates but diamond and CBN and alumina emulsions and sprays on stone surfaces, various natural and even synthetic naguras, tomonaguras in both natural and synthetic slurries and so forth, where we are not only looking at stone surface textures, but mud densities above the stone’s surface and so on in an effort to modulate the stone’s characteristics to our wishes.

Now we can have a topic that can go on for pages and pages…

—
Ken

[cbwx34]

While I do respect Sal (of Spyderco) somehow the idea that two stones of different coarseness are only differing on surface texture seems off – Perhaps a misquote or carelessly worded statement. Don’t know for sure. I’ve heard and seen this idea on the Tormek setup, but this is certainly not a way I would use stones based on JUST the scratch pattern.

Sal is pretty clear on this part… here’s his statements from his forum…

———————————————————————-

All of the ceramics use the same micron size (15-25). the different grits are created by different carriers, different firing techniques and diamond surface grinding.

———————————————————————-

We’ve spent a great deal of time trying to determine grits for our stones. The manufacturer has also worked with us, to no avail. A guess seems to be best.

Most abrasives are measured by the grit size used in the matrix. Our ceramic doesn ‘t work that way. Grit size is constant.

We’ve tried to compare scratch patterns as Cliff mentioned and this is probably the closest, but nothing that we can say “This is blah blah”. Then the Japanese water stones jump into the equation and suddenly there is whole new set of numbers.

So where we end up is:

Our diamonds are a 400 mesh (measureable). (600 on the Duckfoot)

Our gray stone is “medium”. (Same material as fine but different carriers and heat treat).

Our fine stone is fine.

Our extra fine is a surface ground fine.

———————————————————————-

Our Ultra fine stone took many years to develop and few know about them. I was convinced enough with the stone’s potential that we finally were able to make a 3″ X 8″ version that is not much more than a quarter inch thck. Two sides, flat and fine.

It took five years for our R&D teram to finally produce this stone. The challenges kept cropping up and needed to be overcome. Technology in the area of ceramic stones has improved and we can now make stone shapes before not possile.

We have the new UF 3X8, a 2″ X 4″ fine slipstone with 1/2″ down to 1/8″. And we also have a ceramic version of the byrd duckfoot, fine grit. A true “Golden stone”. The downside is the high cost.

50,000 years from now when the Pyramids have crumbled and humans are but a memory, Spyderco ceramic stones will be seen sticking out of the earth, ready to work.

———————————————————————-

I’ve sacrificed a few DMT stones turning fines into ultra fines before we made them. I used them to sharpen my straight razors when I was shaving with one.

————————————————————-
Source: http://www.spyderco.com/forums/showthread.php?31188-Ceramic-benchstones-compared-to-DMT-extra-fine

[Ken Schwartz]

Well if one were to deeply groove a fine stone with a coarse plate and sharpen in a perfectly consistent fashion in say a stroke perpendicular to the blade so that each time you hit exactly the same spot, you might make the argument of some sort of transfer. But for us mere mortals, you don’t do that and you hit the stone +/- one scratch pattern’s width in various places, so it would average out. I can’t imagine actually being able to transfer the scratch pattern, given that with stone wear the scratch pattern is fading as you sharpen.

I suspect that if Sal was asked to comment on that post, he might want to refine his comments 🙂

—
Ken

[Ken Schwartz]

Well perhaps not …

Just speculating on his products as I have not used them, but it may be in the sintering process that he is essentially controlling the agglomeration function so that the finest particles are more friable while the coarser formulations are sintered into each other. Calling each prep the same grit still seems like a stretch.

—
Ken

[Phil Pasteur]

I am pretty sure that I remember that there is also a thread out there where Clay mentions… in a conversation about WEPS ceramic stones and their grit equivalents, that the Ceramic stone producers actually rate their products by surface roughness rather than grit equivalence…
No time to dig it up right now perhaps in the AM..

[Ken Schwartz]

So does this imply that the surface roughness remains constant and that there is no wear, or does it imply that as the surface wears the grit changes? There seems to be something missing with this picture. It seems that one of these two postulates should be true.

And just what is this transfer function or relationship between this ‘engraved’ scratch pattern and the fineness of the finish? Is there an upper and lower limit to how this scratch pattern can control the fineness of finish? And does this react similarly for various steels?

And could I texturize this surface with 0.1 micron diamond film and get a tenth micron honing surface from the ceramic?

So far I remain skeptical.

—
Ken

[Phil Pasteur]

I had some similar thoughts when I read what both Sal and (I think) Clay said. How could the abrasive effect remain constant with wear. Is it possible to make the ceramis so that as new surfaces are exposed they maintain tha same roughness… especially when Sal mentioned using diamond abrasives for testuring what I can only believ ti the very surface of the stone.

OTH, Spyderco started out make sharpeners. They have been doing it for a very long time. It is hard to imagine that Sal is not very knowledgeable on the subject.

There must be something we haven’t come to understand in this thing…

However, the original question that Mark asked was relative to him buying an Atoma plate that was finer then his 140 for texturing his 5K plus grit waterstones. From what you, Ken, and Tom have expressed texture does make a difference at the edge. Both have said that there can be a difference in finish due to stone texturing. This ties in well with what I have written and what I have observed.

I think we could say that Mark would be making a good move by getting a 400 or maybe 600 Atoma for an intermediate stage before using the stones themselves for the final texturing. It is really quite similar to sharpening, the smaller the scratches left at the previous grit, the faster one can remove them at the next level.

So does this imply that the surface roughness remains constant and that there is no wear, or does it imply that as the surface wears the grit changes? There seems to be something missing with this picture. It seems that one of these two postulates should be true.

And just what is this transfer function or relationship between this ‘engraved’ scratch pattern and the fineness of the finish? Is there an upper and lower limit to how this scratch pattern can control the fineness of finish? And does this react similarly for various steels?

And could I texturize this surface with 0.1 micron diamond film and get a tenth micron honing surface from the ceramic?

So far I remain skeptical.

—
Ken

[Phil Pasteur]

I am pretty sure that I remember that there is also a thread out there where Clay mentions… in a conversation about WEPS ceramic stones and their grit equivalents, that the Ceramic stone producers actually rate their products by surface roughness rather than grit equivalence…
No time to dig it up right now perhaps in the AM..

Well here it is, though not exactly as I remembered it.. for whatever it brings to the party…

How the micro-fine ceramics fit into the mix is creating a lot of questions, with me as well. The stone manufacturer uses a different grit rating than what we’re used to (the many we’re used to) call RA, or roughness average. They sent me the specs for the grit early on as 1.4um and .6, but I have doubts that we can really rate it that fine. My new 2000x microscope came this week and my plan is to measure the scratch size that the stones leave and rate them accordingly.

http://wickededgeusa.com/index.php?option=com_kunena&func=view&catid=13&id=3511&limit=10&limitstart=10&Itemid=63#3623

#3623

Though this is only talking about the Microfine Ceramics…which I believe are from Coorstec…
Same manufacturer that makes the Spyderco ceramics.

I am curious to know how the other “many that we’re used to” rate their ceramic abrasives.

Clay?

[cbwx34]

And could I texturize this surface with 0.1 micron diamond film and get a tenth micron honing surface from the ceramic?

So far I remain skeptical.

—
Ken

Can’t imagine you letting this go untested…

… so let us know what you find out! 😉

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