Did I just shave with the world's sharpest straight? (0.125 Cubic Boron Nitride)

[Gamma]

For me, there definitely were notable differences between edges finished on .5µm, .25µm and .1µm diamond.
I will also say that I experienced a definite advantage/improvement when to using .1µm diamond after .25µm.

Now - based on something I read once, I could argue that such a thing is impossible. But after using those abrasives, I think that what I read was either a.) incorrect or b.) missing some pertinent data.

0.25µm? Dunno....maybe. Expensive trial though, and my experiences with diamond sprays has not been all that grand. Sharp, yes - stupid sharp beyone words, extremely tedious and unforgiving but not neccessarily harsh.

Need for it? Probably not, unless we're talking subjectively; i mean, do we even need 1/10th of the stuff we have? No - we don't.
Well - I do need that stuff. Really - I do. So there.

When you get to practical use of sub-micron synthetic abrasives - besides simple 'sharpening' as we think of it, there are other considerations that factor in. Again - need is a difficult word to qualify here.

My biggest gripe with diamond sprays is the narrow target - ever single event was overshadowed by extensive trial/error to get the balance right. The other thing is that I don't really like the stress from shaving with that sort of edge. Way too tedious for me.

 

[eKretz]

Keith, notable differences in feel, or notable differences in keenness level?

 

[Gamma]

Both, although the progress in sharp from .5 to .25 was seemingly greater than it was from .25 to .1.
The progress in smooth was greater from .25 to .1 than it was from .5 to .25.

None of any of that made me terribly happy though.

 

[ken123]

Alex, thanks for the response. As eKretz mentioned the video is done by Dr Matt, using products of mine including the stone and compound. He uses a Veho USB scope and I believe the magnification is at 400 x with a low resolution CCD as part of the package.

"I am thinking that the CB spray grit particles are hard enough to further cleave the silica from the Jnat."

Exactly! So the CBN particle size is purposely selected to be significantly FINER than the stone particles and has several actions including cleaving the silica, yielding a finer slurry at a more rapid rate. A finer CBN is selected so it is not competing with the natural stone but enhancing it, yielding a natural stone finish. Because it is significantly smaller it is also not a problem when using it with suita, unlike larger particles. Also it extends the range of the stone to work better with steels with high vanadium carbides because the CBN is harder than the carbides, unlike natural stone abrasives or even synthetic stone abrasives.

Sharpchef, as eKretz mentions there are SEM micrographs demonstrating 0.1 micron edge widths. Further the idea that you are limited to 0.5 microns has been disproved completely and there is overwhelming experience that edges can be made more refined beyond 0.5 microns. 0.25 microns and half and third micron particulates have been used for years successfully. Finer particulates of CBN and diamond are harder than the carbides, so, far from ripping out carbides, are capable of abrading the carbides as well as the surrounding matrix, so the carbides remain and are more precisely incorporated into the overall geometry of the edge rather than being undermined by breaking down the surrounding matrix around the carbides until they fall out.

---
Ken

 

[Sharpchef]

Sharpchef, as eKretz mentions there are SEM micrographs demonstrating 0.1 micron edge widths. Further the idea that you are limited to 0.5 microns has been disproved completely and there is overwhelming experience that edges can be made more refined beyond 0.5 microns. 0.25 microns and half and third micron particulates have been used for years successfully. Finer particulates of CBN and diamond are harder than the carbides, so, far from ripping out carbides, are capable of abrading the carbides as well as the surrounding matrix, so the carbides remain and are more precisely incorporated into the overall geometry of the edge rather than being undermined by breaking down the surrounding matrix around the carbides until they fall out.

Ok, cool, so we might to shave of every PM Steel?. Next month i will order some of that stuff, and try. Especially with high carbon PM Steels, that are not able too take really fine edges, like the steel of Twin Cermax line (Zwilling kitchen knifes) this would be awsome!.

This will be very usefull for kitchenknifes, for razors i like edges like a good old fashioned coticule can give me, no need for more sharpness, but in the kitchen it can`t be sharp enough.
This diamond compound should easily sharpen keramic knives to HHT as well?

I`am looking forward to try this.

I`am still learning about sharpness, like most of us, so don`t take my posts too serious.

Are there some EU dealers with this stuff?

Greets Sebastian.

 

[eKretz]

Yes, the diamond stuff will definitely sharpen ceramic knives, I've done a few myself.

 

[Seraphim]

Surpass the limitations of steel, and go sapphire:

http://www.tedpella.com/dissect_html/121-18.htm

 

[Sharpchef]

Surpass the limitations of steel, and go sapphire:

http://www.tedpella.com/dissect_html/121-18.htm

We already surpassed the limitations of stones with wet/dry papers (like Film), and be shure i like lapping film!, not as you i suppose but it is a very common way to keep the razors sharp.

Greets Sebastian.

 

[ken123]

"This diamond compound should easily sharpen keramic knives to HHT as well?"

[video]https://youtu.be/NjqnkcPIuCY[/video]

[video]https://youtu.be/pbG8ZckpmTI[/video]





---
Ken

 

[ken123]

And here's one for regular kitchen knives:

[video]https://youtu.be/6YexiF2PkcA[/video]

---
Ken

 

[Gamma]

I don't think they get 'too sharp' - I just think they become too tedious.

I'm not sold on the CBN breaking down slurry faster being accurate - as logical as it might sound, I think it's entirely possible that it's the same speed with/without it. Hard to qualify that, let alone prove it - although it is quite easy to say it.
I'm also not sold on a few other points - larger particles haven't been a problem on Suita, and even if CBN does speed up slurry breakdown I fail to see a proven advantage there. I acually prefer a slower break down usually.
But I'm thinking razors - knife guys might have different needs.
Years ago - I remember reading that someone had a tough time honing his RW S30V straight, not sure if he used stones or not...
But, that was 6 yr ago and people were shaving with PM steel then. Not sure about the other alloys, S90V or whatever.

 

[eKretz]

From the video he made it didn't seem like it added much speed to the process. I haven't watched it recently but I thought I remembered him making many many laps.

 

[Gamma]

I don't think you can quantify speed that way. Too many variables to factor in.
Even so - I don't see the advantage in that scenario. I mean, people have been putting powders on stones for ages, nothing new there, but only in certain circumstances do I see a real practical advantage.

 

[147_Grain]

Is there anywhere that one might find a sample-sized container of the CBN spray, enough for one or two applications to try it out?

 

[Avenolpey]

This quest seems to be about something other than the ultimate shave. The ultimately keen hand honed razor edge is an interesting diversion. How does this keenness compare to a knapped obsidian edge.

 

[Gamma]

If one was to choose edge width as the sole indicator of keen-ness, it would be hard to beat obsidian.

 

[Slash McCoy]

I'll have a pound of the 25 nanometer mono diamond, please.

 

[ken123]

Is there anywhere that one might find a sample-sized container of the CBN spray, enough for one or two applications to try it out?

Please contact me and I'll see what I can do.

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Ken