CPM S90V and Sharpmaker.

yuzuha said:
Ha ha... programmers are crazy people! Maybe that is why I polish small bits of steel on different stones and look at them under a microscope! This lets me pretend I'm doing something interesting while my mind turns into a vegetable ^0^
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Wow! Do you have pictures with comment? I may put it on my site if you are OK in English and also I'll translate it in Russian.

Thanks, Vassili.
 
nozh2002 said:
Wow! Do you have pictures with comment? I may put it on my site if you are OK in English and also I'll translate it in Russian.

Thanks, Vassili.
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Alas, no. I do not have a microscope camera (my scope cost $400 but the 3 headed model with camera cost $600 more). It would be a lot of fun to take pictures and put them on a web site though. Maybe one day I will find a cheap microscope camera that I can slide into one of the two eyepiece tubes.
 
Satrang said:
...Bob Lum and Wayne Goddard compared high vanadium grades to non-vanadium grades. On conventional stones the sharpness was similar. When the high vanadium grades were sharpened on Bob Lum's diamond stones the sharpness of the high vanadium grades more than doubled the others.
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The S30V, 154CM, and CPM 10V knives were nearly identical since they were made by Phil Wilson and nearly the same pattern.
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Several aspects of this stood out as surprising to me based on past conversations I have had with Wilson and what I have read by Goddard on sharpening. I discussed it with both of them recently and did not get the same perspective as described in the above. Both tend to prefer the Norton SiC/India hones, and don't promote diamond hones. Neither will support a claim of double sharpness for high vanadium grades.

-Cliff
 
I've a Larry Chew's Covert Spitfire to sharpen.
It's S90V at 57RC.
Yesterday I read this thread and now I'm even more confused!!

I received it with a 18° per side asset.
I went Brown Spydie rods at 20° for microbevel and now looks like sharper to some extent.

But the point is: is it just more toothy or are the V carbides really exposed and exploited at their best?
These carbides (S30V and S90V) are said to be 2-4microns, so should I run for diamond abrasives with inferior micron dimension (i.e. 1micron)?
DMT Red is 25micron and Green is 9micron. Greater than carbides yet harder.
Thus would they be an advantage over Brown (aluminium-oxide) rods from Spyderco as far as V carbide exposure is concerned (and thus the slicing cutting power)? Furthermore would they bring about more edge stability?

Last but not least: would you recommend going under 20° per side with such a steel at such an hardness?

Thanks once again

Daniele Berti
 
This is old thread. Now I have no problem sharpening CPM S90V and use after DMT Extra Fine (9microns) leather loaded with Green Rouge and then leather loaded with 0.15 micron (100000 Mesh) diamond powder to make my Microtech CPM s90v whittling hair.

But Ceramic works only up to 2 microm levels on high vanadium steel - which honestly most consider as "scary sharp", difference can be seen only with thread testing, really or hair whittling.

Thanks, Vassili.
 
This is great stuff, thanks to all who posted info, especially nozh2002. I am going come back and reread it, maybe right after a cup of coffee. I am sweating like a pig trying to figure it all out.
 
Just received the answer from Ben (EdgePro) about grits, medium and microns of his stones and tapes:
"Dan,
The 120 is SC and the 220 320 and 800 are aluminum Oxide.
The 2000 and 6000 tapes are SiC and the 1000 and 3000 are AO.
Microns are 120- 116, 220-66, 320-36, 800-14 -, 1000-12, 2000-9, 3000-3, 6000-1
Ben"

Hope this helps many of us
 
Thanks Vassilli. This is the very best demonstration ever. Should make our knives all better. Thanks so very much.
 
hello,

I just read that :

Also I have great link from daverave999's answer on my question on Spyderco forum http://208.63.68.209/SharpenGuide.htm#Grit

ExtraFine is 3 microns
Fine is 6 microns
Medium is 15 microns

So that means that the stone DC4 fallkniven in 25 mic will sharp "Less" than the spyderco medium rod of the sharpmaker ?

I dont see the interest to sharp in 25 mic. Why those DC4 are so much hyped so ?
 
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