Chosera stone maintenance

[wickededge]

More of the sample sharpened with the lapped stones:

2000x at 13 degrees

2000x at 20 degrees

2000x at 35 degrees

Attachments:

• Lapped-2000x-13-deg.jpg
• Lapped-2000x-20-deg.jpg
• Lapped-2000x-35-deg.jpg

-Clay

[Phil Pasteur]

So… how were the samples ( I presume to be used as a baseline??), in the first two photos prepared?

[wickededge]

I think the clearest view of the edge is at 35 degrees. Here are the lapped and textured results together at 2000x:

Stone Lapped Smooth

Stone Textured at 50#

Attachments:

• Lapped-2000x-35-deg_2013-06-19.jpg
• Textured-2000x-35-deg_2013-06-19.jpg

-Clay

[Phil Pasteur]

I think that I see some difference. Not as much as I thought would be there though.
As this is 2000X, I am not sure whether the differences would even be perceptable when evaluating performance.

[Johpe]

Those are some amazing pictures!

Looking at the scratches you get from the finely lapped 10k chosera and the polish you start with I’m really curios on how the edge was prepared I am the first place? That has to be the most scratch free edge I’ve ever seen! (and I though 10k chosera would give you a nice mirror edge 🙂

[wickededge]

I think that I see some difference. Not as much as I thought would be there though.
As this is 2000X, I am not sure whether the differences would even be perceptable when evaluating performance.

There is definitely some difference and I think it’s important to keep in mind that we’re only seeing a very small section of blade in the image, approximately 120 microns long or 0.0047″, so if we see even a handful of extra teeth, say five, in the image of the sample sharpened with textured stone, it would translate to over 4200 micro-teeth along a 4″ blade. I think there would be a noticeable change in cutting performance to the skilled hand.

One thing that stood out was how relatively soft the waterstones are. It was very quick and easy to lap them flat and add texture, maybe a minute or two per stone whereas flattening and texturing the ceramics took me nearly 1/2 hour per stone. I came away with the impression that whatever texture is added to a waterstone will be flattened out fairly quickly through the course of regular sharpening, so deliberately texturing a waterstone as a strategy might not be a great idea. I think one would end up grinding away their stones fairly quickly when what was really needed was a coarser stone.

-Clay

[wickededge]

Those are some amazing pictures!

Looking at the scratches you get from the finely lapped 10k chosera and the polish you start with I’m really curios on how the edge was prepared I am the first place? That has to be the most scratch free edge I’ve ever seen! (and I though 10k chosera would give you a nice mirror edge 🙂

Thanks Johannes! Those samples were prepared using all the stock diamond plates, the ceramic stones and a lot of stropping, finishing on the kangaroo strops with diamond sprays.

-Clay

[Mark76]

Great experiments, Clay! So simple and I guess they have provided a definitive answer.

I indeed also see some differences, but not nearly as much as with the ceramic stones. What strikes me is not so much that the textured stones produce more scratches (some more, it looks to me, although I haven’t counted them), but that they seem to produce a couple of quite deep ones close to the edge. Or could this be due to a slightly different angle or other change in sharpening technique?

I’ll definitely consider re-texturing my high-grit Choseras and (particularly) Shaptons with 1K diamond stones (or the 3 mu DMT stones… 🙂 ) after flattening them.

Molecule Polishing: my blog about sharpening with the Wicked Edge

[Phil Pasteur]

I indeed also see some differences, but not nearly as much as with the ceramic stones. What strikes me is not so much that the textured stones produce more scratches (some more, it looks to me, although I haven’t counted them), but that they seem to produce a couple of quite deep ones close to the edge. Or could this be due to a slightly different angle or other change in sharpening technique?

Based on the hardness and durability of the ceramic material, the quantitative difference should be significantly different with those stones. We originally were talking about the Chosera stones though. The ceramic stones got into the conversation only by way of an example of what texturing can do to change the effect of a stone at the edge.

I’ll definitely consider re-texturing my high-grit Choseras and (particularly) Shaptons with 1K diamond stones (or the 3 mu DMT stones… 🙂 ) after flattening them.

Definitely a good idea. Both in light of the objective evidence and the experience based opinions of those such as Tom. I wasn’t quite sure how the conclusion was arrived at that there was no effect.

[Phil Pasteur]

There is definitely some difference and I think it’s important to keep in mind that we’re only seeing a very small section of blade in the image, approximately 120 microns long or 0.0047″, so if we see even a handful of extra teeth, say five, in the image of the sample sharpened with textured stone, it would translate to over 4200 micro-teeth along a 4″ blade. I think there would be a noticeable change in cutting performance to the skilled hand.

Yes, it is all about perspective. Even though I know photos are at 800 or 2000X it is a bit hard to adjust the brain when viewing them. The 4200 teeth in a 4 inch blade numbers definitely put it into terms more readily assimilated.

One thing that stood out was how relatively soft the waterstones are. It was very quick and easy to lap them flat and add texture, maybe a minute or two per stone whereas flattening and texturing the ceramics took me nearly 1/2 hour per stone. I came away with the impression that whatever texture is added to a waterstone will be flattened out fairly quickly through the course of regular sharpening, so deliberately texturing a waterstone as a strategy might not be a great idea. I think one would end up grinding away their stones fairly quickly when what was really needed was a coarser stone

.

Agreed. Looking at it from the other perspective though, if one likes the edge obtained with a very smooth stone, it would obviously be worthwhile to leave a texture as fine as possible (as close to the native texture of the stone that is) on their high grit stones after lapping/flattening. Consistency is important!

[cbwx34]

While the answer to “does it have an affect” is answered, at least in this example, I’m not sure coming to the conclusion that lapping or texturing your stone to a fine finish, is necessarily the correct (or incorrect) one. There are still a few questions to be answered, for example, how long does the affect last, or, what does leaving a stone “rough” do? For example, i’ve found that some “high grit” stones I’ve used actually perform better if left with a rough finish, they’ll break down quicker and ultimately leave a better polish, than if they’re lapped smooth to begin with. And of course, the end user might like an edge better that has the “micro teeth” the stone leaves… (not that you want to purposely rough up a stone to try and provide a more coarse finish). Some of these questions/preferences will probably be left up to the individual sharpener and their situation.

Still a bit of experimenting to do (fortunately for Clay, not all involve a microscope). 🙂

[Phil Pasteur]

All of the questions will be left up to the individual sharpener. We all do things a bit differently.
My thought is simply that if the effect that you are after is the one produced by the smooth surface of the stone, before lapping, then a fine texture will get you closer to that effect faster. I am not sure how this would be something that is not pretty obvious to most sharpeners. It seems pretty intuitive, to me anyway.

Apparently there are all kinds of stages of texturing that can be used for different results. Each sharpener will have to decide whether using this method to achieve a result is efficient. Notice, no correct nor incorrect in the statement. Those terms imply that there is a specific right or wrong methods involved.
I would also think, especially considering how many times the phrase, “it depends” is used in sharpening discussions… that correct or incorrect are not descriptions that we need to apply to any solution (except maybe keeping ones fingers away from a sharp blade) :S .

Maybe better, if you want “X” results, we have seen that this process can get you there. Try it and see what you think..:whistle:

I think, OTH, that if one wants the effects of a more course stone, they would be better off using a more course stone rather than texturing something as soft as most water stones.

[wickededge]

I learned a couple neat things from this experiment:

1. With lapping/texturing I can tweak my Micro-Fine Ceramics to a preferred finish that will convey to the knives I’m sharpening, bevel and edge. The texture I create will leave coarser or finer scratch patterns as desired and the stones are hard enough to hold that texture for quite a while.
2. I won’t bother to texture my waterstones for effect because they are soft enough that the effect will be so short lived as to not be worth the amount of (expensive) stone lost in the process.
3. Adding a tiny bit of texture before rubbing my waterstones together will speed the process of developing a slurry. This seem to only matter on my 5k/10k stones. The lower grit stones develop a slurry very quickly when rubbed together.

If I want more tooth on the edge of a well polished blade, I create a very small micro-bevel with the desired grit. In that spirit, if I finish a knife with my 10k stones but want more bite, I’ll go out a degree or so and make a couple very light passes with a coarser stone.

-Clay

[cbwx34]

My thought is simply that if the effect that you are after is the one produced by the smooth surface of the stone, before lapping, then a fine texture will get you closer to that effect faster. I am not sure how this would be something that is not pretty obvious to most sharpeners. It seems pretty intuitive, to me anyway.

It seems intuitive, but it’s not. Your statement is correct, that if you desire the finish left by a stone with a smooth surface, then yes it’s obvious… lap/texture your stone to that level. (It’s actually a self fulfilling prophecy.)

But if your desire is to have a fine grit stone give you the finest “best polish” finish possible (that in some of the posts I got the impression that’s what some people are after)… lapping/texturing it to a fine finish won’t necessarily give you that, and actually in most cases won’t. (Talking Choseras here… Shaptons are a bit different also). It goes to Clay’s 3rd point that I just saw… a bit of texture helps the stone break down, develop a slurry, and provide a better finish.

There’s a distinct difference between these two desired results. And it has nothing to do with trying to get a more coarse finish from a fine stone, which everyone seems to agree, that there’s a better route to take.

[Eamon Mc Gowan]

Wow has this been an education! As in so many things sharping. I really learn so much here on this forum. I had no idea or concept about texturing a stone prior to this thread. Maybe it is intuitive to some but I only know a few people that can sharpen a knife and out of them I really don’t think they know how to texture a stone?
I think whenever someone gets more and more into their hobby the more we become “purist”. Forgetting what it is like to be new? I see it on the gun range all the time. The range safety officer will give the command to “lock you bolts open-make your weapon clear”. New people just stare at each other? When he should have said “unload your gun-make them safe”.
It has taken almost to the end of this thread for me to understand where you guys have been coming from? It wasn’t till Clay gave the observation about so many “teeth per micron” that I had a clue what was trying to be achieved? I am very grateful to all who taught me so much in this thread and to Clay for all your hard work!

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