Ken Schwartz

[Ken Schwartz]

I’d have to agree. It seems like the micrographs are of excellent quality, but the honing technique is not convincing. And the concept that coarse particles have no effect on an edge simply is not accurate. If it were true, we would simply have one grit size. Am I missing something in the discussion?

I’d also agree that paper alone has abrasive properties. And that different papers have different properties, from coarse papers, to extremely fine writing papers. This is a larger topic in terms of what are suitable substrates for various grits.

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Ken

[Ken Schwartz]

I took one of Tom’s pics – the Shapton 5k stone texturized with the 600 grit Atoma – and did a bit of image processing to bring out the scratch pattern a bit more to see the scratches more clearly. I cropped an interesting area of the image – in the right quadrant, the lower left portion of it.

overview:

Cropped closeup image:

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Ken

[Ken Schwartz]

Clay, That’s a particularly useful micrograph to help us characterize the problem more fully.

So a few things stand out:

The particles are clearly fused, still seeing some degree of demarcation preserved between the particles, but obviously the particles are fused to a degree where they are not moving about (discussed more in detail real soon)

The particle size is quite variable 2.4 – 44.8 microns or roughly 7000 grit to ~ 300 grit in size (rough figures in my head)

The particles themselves have been polished on their surface with something harder than the particles themselves to what appears to be a coplanar surface with gaps between the fused particles. This coplanar surface with gaps between the fused particles is what is being presented to whatever is going to be sharpened on the surface. This is roughly (sorry for the pun) analogous to a balsa surface where the surface has gaps. The gaps are largely irrelevant in both instances.

What IS relevant is the surface texture of the balsa or in this case the surface texture of the abraded ceramic particles.

As you can see in the measurement bar that is 10 microns in size (lower right), this image is really incapable of answering the real question we have in front of us.

What is needed is to resolve the SURFACE texture of this interrupted polished surface.

I would suggest having the sample reshot at both 10x and 100x the current magnification (bars for 1 micron and 0.1 microns, respectively).

The answers lie in resolving the surface textures and characteristics of this planar surface, not the fused particle sizes.

This micrograph is a good and entirely necessary first step in ‘resolving’ this topic, but cannot provide a definitive answer by itself. There is more to learn.

As an aside, I would also be quite concerned with the potential of a surface of this nature to harbor coarser swarf and ceramic chip residue which could ruin the finish easily when compared to the finer surface texture of the coplanar surface.

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Ken

[Ken Schwartz]

Well I don’t have one of these ceramic stones to test so that’s one issue. Second, I somehow doubt that I could refine the surface texture to that fine a surface so I would have to test coarser finishes. And to be perfectly candid, given well over a hundred natural stones of various types, new compound formulations, etc, to test and dealing with a bunch of backorders, I can’t honestly say that testing a product I don’t sell is a very high priority. If I needed that fine of a texture, I would simply use the film or CBN or Poly directly, rather than using a less hard substance.

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Ken

[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.

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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.

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Ken

[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 🙂

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Ken

[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…

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Ken

[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.

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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.

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Ken

[Ken Schwartz]

The nanocloth has no silicates like the leather or even paper contains. These silicates are harder than steel on the Mohs hardness scale, hence they are capable of abrasion.

If you strop on nanocloth with no compound, you get no metal swarf unlike leather – even ‘roo. Even with a light spray of 0.025 poly applied to nanocloth, you will see metal swarf. On leather you see some metal swarf residue, less so on ‘roo but some without the application of any compound. So there is clearly some abrasive component to leather itself. Even fine paper has some level of abrasive, presumably from the wood pulp itself as well as the water particulates involved in paper production. Clairfontaine, a paper mill, owns their own stream and has finer control than most of the abrasive content of their writing paper. Similarly sugar cane based papers seem to have particularly (sorry for the pun) fine surface properties.

At a micro or even nano level, perhaps our definitions fail us and it is best to simply strive to characterize the observations rather than to fit it into preconceived ideas of burnishing or abrasion but rather some hybrid of the two. Clearly the particles are capable of scratching the metal and in so doing both move and push the metal around to some degree. The grooves from the hard particle creating a scratch both remove some metal and push the metal out of the way of the path of the particle. Given the non-spherical shape of silicates – more sheet like, for a given particle size you would expect less depth of cut from a corn flake shape than a bowling ball (sphere) shape. You see this with natural stones too.

So at the lower particle sizes, I think nanocloth ‘rules’ in that it holds more particles more easily and is a bit cheaper than ‘roo but far more consistent than bovine or horse. It’s matrix allows for particles to become entangled more easily and hold their position which would favor abrasion. If the particles roll around, this favors (IMO) burnishing a bit more. At the high end, this becomes interesting in that nanocloth is more of a ‘pure’ play, but ‘roo brings a draw characteristic to the table. Perhaps this draw causes a smearing effect that the nanocloth doesn’t which MAY be advantageous, combining fine abrasion with dragging the surface around a bit too, which may be counterbalanced by the combined abrasion of the fine CBN / Poly particles against the somewhat coarser silicates. Just some theories on how I see it, but what is actually happening would best support or refute my thoughts with some carefully controlled experiments and detailed inspection under an SEM.

FWIW, you can see this rolling around phenomena more readily if you put some 80 micron CBN on Balsa. Some particles roll around pretty freely, some stick out half way in the balsa and stay in place and some get buried in the balsa producing little effect. Think about this next time you are eating a poppy seed bagel as they are of a similar size 🙂 Just don’t get too carried away in a restaurant playing with your bagels 🙂

At these really fine grits, the desired result may not be the same for all. For straight razor users, comfort rules even over sharpness and ‘roo vs nano might go one way and for knife users, perhaps the other way. Time will tell.

Pardon the rambling post, but perhaps it might provide some fodder for discussion.

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Ken

[Ken Schwartz]

As I mentioned in another thread, my new emulsion formulation products absorb quickly into the leather ready for immediate use AND condition the leather – best of both worlds for the conditioner and the grit to be the same formula. Therefore when you add new compound to refresh the strop you recondition the leather 🙂

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Ken

[Ken Schwartz]

While I do appreciate the enthusiasm in the video, it’s not how I would recommend using my sprays. Curtis’ approach is much more like it. The only advantage [to me] of using the technique is that you will be using my products more quickly and reordering more 🙂

Put the paddle down on some background – not up in the air overspraying the entire area with abrasive including the table and the WE itself. Put the two paddles next to each other.

Select the grit you wish to apply. Lightly spray the leather. Just a couple of pumps is more than enough. Let dry. DON’T use an ungloved hand, even a washed hand to smear it around. You will get abrasive all over your fingers and dirt from your hands on the strop. You aren’t smearing chunky peanut butter, you are making a thin layer of 25 nanometer particles and few hands are washed down to 25 nanometer cleanliness. Let it dry. Want another coat? Spray again. Use smooth strokes, not spastic jerks back and forth. One pump in one direction, another in the other direction. Maybe a third spritz. Let dry and enjoy. If you don’t get a PERFECT even coat – DON”T WORRY about it! Over time with subsequent reloads this will even out.

Don’t let your obsessiveness get the better of you. You know who I’m talking about. ALL of us have a perfectionistic streak of we wouldn’t be talking about getting great near perfect edges.

Let dry and do other side, laying it on a clean disposable surface to catch overspray.

TIP – Use copy paper or a similar surface to catch the overspray – or something nicer. Then use that oversprayed paper as a freehand strop or for a fingerstone type of polish on curved surfaces of the knife.

AS an update, I now have an emulsion formulation for many of my popular CBN and Diamond grits. With these products, for a WE sized strop, I recommend applying 1 drop on the paddle and smearing it around quickly with a gloved finger for a few seconds to even it out (within reason). No overspray at all it’s like applying a skin conditioner. Wear a disposable glove or else it will absorb into your hand rather than the leather and it won’t spread as far. It absorbs rapidly and is available for use almost immediately. It also works on nanocloth, felt and other leathers, but the best is on Kangaroo. Nanocloth requires a heavier application but produces a significantly heavier coating due to reduced ability to spread on nanocloth. This can be an advantage.

Available in a wide range of grit sizes in polycrystalline CBN and soon in monocrystalline diamond emulsions. Additionally in a few sizes of Aluminum oxide too.

CBN grits from 80 microns to 0.1 microns – 80 45 30 15 9 4 2 1.5 1 0.75 0.50 0.25 0.125 and 0.1 microns.

Poly diamond in 0.025 0.050 0.1 0.25 0.5 1.0 2.0 4.0 microns.

Mono – please contact me for details.

I can sell these in the regular 2 oz bottles or sell small amounts in syringes if you want a ‘taste’.

Clay has tried the 0.1 micron CBN. So far I have only gotten positive reviews from early users of these emulsions.

To be clear, I am NOT discontinuing the slurry formulations. These emulsions are an additional series of products.

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Ken

Mono – please contact me for details.

[Ken Schwartz]

Yes I do have glass Platens for the Wicked Edge in stock – as well as diamond films for them. PM me for information.

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Ken

[Ken Schwartz]

The steel in Globals is not particularly hard compared to many other Japanese blades. It really isn’t necessary or desirable to go below 15 degrees per side on these knives. It also isn’t necessary to have a convex grind on them either. Besides a flat grind at 15 degrees is going to be a more acute edge on the Wicked edge than a freehand grind at say 12 degrees simply because the actual angle at the edg of the edge will be less acute, so the Wicked edge at 15 degrees is more than enough for a Global.

Using the basic diamonds that come with the WE and adding say a 2k 5k Chocera combination should be all you need for these knives.

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Ken

1 user thanked author for this post.

SalisburySam

[Ken Schwartz]

In many instances the difference is unimportant between poly and CBN, so cost favors CBN.

For straight razor use, the verdict is pretty clear. At say 1/4 micron the CBN delivers a more comfortable shave. At tenth micron it’s a close call. Beyond that CBN isn’t available so there’s no contest. But the good news is that at a particle size 10x finer (0.025 micron vs 0.25 micron) the issue of comfort doesn’t remain a problem – the 10x finer scratch pattern isn’t a comfort problem, but it is – as expected – incredibly sharp.

For knife use, the balance goes more towards poly diamond, giving a more ‘toothy’ aggressive style of edge. Some of my customers swear by it and only want the poly, which I have available directly in grits from 4 2 1 0.5 0.25 .1 .050 and 0.025 microns. But quite often the vote goes to CBN for cost and because at the lower cost it still delivers a spectacular edge. Also I have a wider range of sizes of CBN going from as fine as 0.1 micron on up to 80 microns – 0.1 0.125 0.25 0.5 0.75 1.0 1.5 2 4 9 15 30 45 and 80 microns. Personally I use CBN most of the time. BTW for mono fans, I also carry mono in 0.025 0.050 0.1 microns too. I am also including an emulsion based formulation for both CBN and poly and mono in an ever expanding lineup. This is yet another topic. Early release of some of these in sample sized volumes is anticipated shortly. PM me if this is of interest.

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Ken

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