CBN sprays on waterstones

[wickededge]

Phil,

Thanks for drawing attention to the section on the carbides. I guess I had an ADD moment while reading it through the first time and didn’t key into this:

Now when you have carbides harder than the surrounding steel matrix, the softer abrasives grind away on the surrounding matrix until the carbides are no longer supported and fall out from lack of support. I like to use the analogy of a chocolate chip cookie with the carbides being the chips and the surrounding steel being the dough. So when the dough gets worn away the chips fall out.

Seeing this effect isn’t possible w/ my optics; we’d need use of an SEM to verify whether carbides are actually falling out. All of it makes me wonder a bit… Wouldn’t the softer matrix still wear away more quickly with a harder abrasive? What if any difference does the particle size make when it comes to this issue?

I’ll work on my REX 121 blade a little and see what shows up under the scope.

-Clay

[wickededge]

I did try this technique with my 3k, 5k and 10k stones. I started with the stones dry, sprayed the CBN and used the moisture of the spray to create my mud while rubbing the stones together. Seemed a sensible way to get started. I used the following combos: 3k/.75um, 5k/.5um, 10/.25um. The mud developed really quickly and easily. I typically don’t get much mud with the 5k and 10k stones and I was pleased to see that more formed and more easily using the CBN sprays. I imagine that the harder CBN particles help to break down the waterstone grits so you get a finer mud more quickly but I don’t have a way to test that theory. I can’t speak about results yet. I’ll have to devise some tests to see if I can spot any differences in results etc, especially with harder steels.

-Clay

[Leo Barr]

I think like most of us we- you -I _plus most of the people on the forum are passionate about sharpening and often can not get the words typed out quickly enough to make a point so yes sometimes I know I certainly write in a forceful manner put us all together in a room and probable the same thing would occur but what magic would prevail the knowledge and experience held by all in the forum would be phenomenal so maintain your passion Philip

Leo

[Leo Barr]

Do you have a picture of you REX121 I have seen one on a forum and Rex sounds a suitable beastly name for such it is a sort of Katana styled folder the one I have seem with a sort of brut forge look to it so only the thinning bevels shine.

[Phil Pasteur]

I was looking for something that talked about carbide sizes. I found a paper on forming metals that used CPM 15V, CPM S30V and K190 steel and measured the size of carbides. Surprisingly they were found to be between 1 and 5 microns. There are SEM images with a 10 micron scale on them and individual carbides seem to be visible.

Wouldn’t this be something that could be displayed at 2500X ?

In the initial structures of the supplied steels there were differences in morphology and scatter of carbides (fig. 1). The carbides of steel CPM 15V had a mainly polyhedral character with a size of 1-3 μm. The finest carbides were found in steel CPM S30V which has a high content of chromium. On the contrary in the steel K190 there was a sharp morphology of carbides, the carbides size was inhomogeneous between 1 and 5 μm and these carbides can be several times bigger than the rest of the carbides. Thanks to the linear chemical analyses EDX it was found that the carbides of CPM S30V are mainly made from vanadium but the steels CPM 15V and K190 have chromium carbides(fig. 1).

It get pretty esoteric from there though.

http://www.comat.cz/files/proceedings/11/reports/1207.pdf

[Leo Barr]

Should be interesting to see where this goes and would there be any advantage to using them on the finest ceramics or would that be counter productive I am just wondering if the correct application of these CBNs could cut down on stropping since it sounds as if the quest fore the perfect finish takes a lot of stropping especially so for someone with out a set of Choseras having those must cut the stropping time down since the edge is pretty well polished .
A question on Choseras has anyone looked at the price of what the 30k Choseras would cost to mount on the WE I think the full sized stone is a little over 270€ but if you had that with a dash of CBN there would hardly be a need to strop I would imagine.

[Phil Pasteur]

Do you mean the 30K Shapton stone?
At one time Clay sold them. They were real pricey.
If you read a bit, I think you will find that many think the 10K Chosera is a better polishing stone than the 30K Shapton.

[wickededge]

Phil,

Here’s a shot of the REX-121 Mule at 2000x:

For reference, here it is at lower magnification – 230x:

Attachments:

• h27c80f3.jpg
• h36f996a.jpg

-Clay

[wickededge]

Leo,

Here’s a picture of the knife:

Attachments:

• hd389cea.jpg

-Clay

[Leo Barr]

My confusion getting late here (long night last night the weather changed end of summer thunder and lightening plus monsoon type rain and now the air temperature down 5ËšC )although I see Naniwa do a 12k stone yes you are quite right Shapton do the 30k.

[Leo Barr]

Thats awesome the one I have seen is similar but I think it was a folder .
Do you have any intention of putting a handle on it be it paracord or carbon fibre scales could be suitable hightech and interesting.
Thanks for the picture!

[wickededge]

Thats awesome the one I have seen is similar but I think it was a folder .
Do you have any intention of putting a handle on it be it paracord or carbon fibre scales could be suitable hightech and interesting.
Thanks for the picture!

I originally had a cord handle on it:

I have some G10 material to make scales, just haven’t found the time to make a project of it. Carbon fiber would be even cooler.

This might be the folder you’re thinking of:

This one belongs to Leo Mitchell. He had it sent to me for sharpening and I got the chance to fool with it a bit. It’s a beast.

Attachments:

• hbea8cd6.jpg
• hb4e1826.jpg

-Clay

[Leo Barr]

That certainly looks like the culprit !

[Phil Pasteur]

Phil,

Here’s a shot of the REX-121 Mule at 2000x:

That is some real gnarly looking steel
👿

Is it my imagination… does it look like those irregular blobs (sorry for hyper technical reference) are raised above the rest of the steel. It almost looks like the material that appears lower shows scratches (abrasion caused striations ??) whereas the raised areas do not. Interesting for sure. I wonder if we are looking at carbides… you know the blobs… with the softer material having been abraded away around them…

Hmmm.
😛

[wickededge]

Phil,

Here’s a shot of the REX-121 Mule at 2000x:

That is some real gnarly looking steel
👿

Is it my imagination… does it look like those irregular blobs (sorry for hyper technical reference) are raised above the rest of the steel. It almost looks like the material that appears lower shows scratches (abrasion caused striations ??) whereas the raised areas do not. Interesting for sure. I wonder if we are looking at carbides… you know the blobs… with the softer material having been abraded away around them…

Hmmm.
:P[/quote]

I was thinking the same about the carbides, comparing that photo to the PDF you linked. They have some very similar characteristics.

-Clay

[Author]

Posts