reprofiling s30v is a b!tch

Cliff Stamp said:
Burrs form by a number of methods, the most common seen when honing is a deformation burr where the edge folds over because the pressure on the edge is too high and the cutting aggression too low - thus it deforms rather than be cut. Therefore you would predict for example that a loaded stone would be far more likely to induce a deformation burr than a clean one - which is indeed the case....
-Cliff
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So, if I got it right.
Assume this is the burr __/ if I should project direct light over it I should be able to catch some "black" area inside it between rightmost _ and / .
Should I be able to get a evenly lighted edge, the burr would not be present. Right?

[OT]If I recall well you should own something from Phil Whilson made of CPM10V.
How would you compare it to S90V (thoughness and edge holding).

[OT]
How would you compare S90V and ZDP189 as far as corrosion resistance, toughness, wear resistance and edge holding are concerned?

You can PM me the OT answers if you wish.

Thanks
 
daberti said:
So, if I got it right. ...
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Yes.

Should I be able to get a evenly lighted edge, the burr would not be present.
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Yes, you won't see much of anything then.

[10V]

How would you compare it to S90V (thoughness and edge holding).
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Wilson generally notes 10V is tougher for his knives which seems reasonable as I saw easier chipping with his S90V vs his 10V, but to be clear you are talking about inherently fairly brittle steels, neither of them would be respond well to impacts or bending. 10V would be expected to have better edge stability however it would be again low for both and both are extreme high wear and very difficult to grind. The largest difference would be seen in the hardness as it is easier to get 10V very hard and that is where you want to run these alloys. If you get these softer they would be very difficult to sharpen.

How would you compare S90V and ZDP189 as far as corrosion resistance, toughness, wear resistance and edge holding are concerned?
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These are two very similar steels, both are P/M, high wear, high carbide stainless. Spyderco has CATRA data which show these to be similar for long term blunting which is reasonable based on what I have seen comparing ZDP-189 to S30V. I would be interested in a detailed comparison of them because it would make some interesting points about edge stability I am curious about because the smaller vanadium carbides should be more stable than the larger fraction of chromium carbides in ZDP-189. S90V would also be expected to be tougher due to the smaller carbide fraction but again neither of these are tough and would respond well to impacts or bending. S90V has also recieved some complaints about sharpening due to the high vanadium content, not responding well to a sharpmaker for example at very high finishes.

-Cliff
 
Cliff Stamp said:
These are two very similar steels, both are P/M, high wear, high carbide stainless. Spyderco has CATRA data which show these to be similar for long term blunting which is reasonable based on what I have seen comparing ZDP-189 to S30V. I would be interested in a detailed comparison of them because it would make some interesting points about edge stability I am curious about because the smaller vanadium carbides should be more stable than the larger fraction of chromium carbides in ZDP-189. S90V would also be expected to be tougher due to the smaller carbide fraction but again neither of these are tough and would respond well to impacts or bending. S90V has also recieved some complaints about sharpening due to the high vanadium content, not responding well to a sharpmaker for example at very high finishes.

-Cliff
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My understanding is that edge retention would be the same under normal circumstances, but S90V would be quite superior when cutting abrasive media. S90V toughness should be superior and corrosion resistance too, as ZDP is less corr. resistant than even ATS-34
I just cross compared basing on this literature (posted on a site of mine for practical purposes)
http://www.egoproject.info/download/zdp189_eng.pdf
http://www.egoproject.info/download/dss90v8.pdf
 
daberti said:
My understanding is that edge retention would be the same under normal circumstances, but S90V would be quite superior when cutting abrasive media.
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This is a bit complicated because it depends on how you are cutting the material. Steels which have low edge stability for example can actually increase sharpness in extended use by micro-chipping to create a saw effect. However this doesn't help for push cutting.

I'd like to see micro-graphs of both of these steels with some details on the exact type of the carbide structure. With the much higher hardness of ZDP-189 it would seem to predict a higher carbide stability given a similar volume/size.

ZDP-189 has a large hardness increase over S90V which will likely make a large difference short term. A lot of people are also praising it for ease of sharpening which is rare to be said of S90V.

Added to this is Super Gold G2 which is another high wear P/M stainless. There are also P/M stainless HSS being made in japan which also combine a very high hardness and wear resistance. There is little information available on them however.

S90V toughness should be superior and corrosion resistance too, as ZDP is less corr. resistant than even ATS-34
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Yes, the toughness would be expected because using vanadium you can get similar wear resistance in a smaller volume and thus increase toughness - on a bulk piece of material. I would be cautious however about immediately assuming this is true for knife edges though as there are a number of other factors of influence.

I would expect S90V to be more corrosion resistant than ZDP-189 simply because of the massive carbon content in ZDP-189 and this has to reduce the free chroimum. However with a high enough carbide volume you need less free chroimum to be corrosion resistant. Some details on the composition wuold be of interest, exact volume fraction of carbides, free chroimum, etc. .

In general for knives you also want Q-fog more so than strong acid resistance. Glesser has mentioned recently that they will be doing some material testing and hopefully he will release Q-fog data on ZDP-189. I would also like to see the full CATRA curves.

-Cliff
 
Continuous salt spray was used for quite awhile to attempt to predict enviromental corrosion resistance. However it didn't correlate well, the data was very precise but not accurate. So interrupted salt sprays were used which were less precise ubt more accurate. Eventually someone built a machine which did this cyclying, the q-fog. It can do fog, dry, or high humidty and cycle to simulate a natural enviroment.

This is just the same thing as hanging the blades on a clothesline. The q-fog machine just reduces the variance and thus allows a much more consistent result with a much smaller sample time. This is a common approach in research, if you throw a lot of money at a problem you can get an answer in a much shorter period of time.

-Cliff
 
For some reason, my edges off the Norton Economy (A/O?) aren't as flat and as crisp as my edges off the diamonds. I think it's just me. I can't tell if I'm hitting the entire bevel or not, on oil stones.
DMT coarse- pocket sized- reprofiled my BM5000S in 10 minutes (after I adjusted the angle twice)
 
Cliff Stamp said:
Continuous salt spray was used for quite awhile to attempt to predict enviromental corrosion resistance. However it didn't correlate well, the data was very precise but not accurate. So interrupted salt sprays were used which were less precise ubt more accurate. Eventually someone built a machine which did this cyclying, the q-fog. It can do fog, dry, or high humidty and cycle to simulate a natural enviroment.

This is just the same thing as hanging the blades on a clothesline. The q-fog machine just reduces the variance and thus allows a much more consistent result with a much smaller sample time. This is a common approach in research, if you throw a lot of money at a problem you can get an answer in a much shorter period of time.

-Cliff
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I see. I guess that by bringing to me some extra toughness and edge keeping on par with ZDP189, has been the best choice.
I've sharpened WH and Calypso ZDP, and, on the other hand Kevin Wilkins S90V. I can fairly say that with DMT stones KW S90V sharpening had not been an issue at all ;)
 
Yes, pretty much everything looks soft compared to diamond. The only real issue I have found is that there is a bit of a static electricity burr issue, some water helps.

-Cliff
 
Cliff Stamp said:
Yes, pretty much everything looks soft compared to diamond. The only real issue I have found is that there is a bit of a static electricity burr issue, some water helps.

-Cliff
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Uuuhhhh?:confused:
 
After sharpening on dry diamond plates, when I check the edge under magnification there is debris stuck to the edge by a static attraction. I generally use plain leather and a few trailing passes to remove the worst of it.

-Cliff
 
Cliff Stamp said:
After sharpening on dry diamond plates, when I check the edge under magnification there is debris stuck to the edge by a static attraction. I generally use plain leather and a few trailing passes to remove the worst of it.

-Cliff
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I saw it too!! I thought I was drunk, but I was not. Did it happen to you only with S90V as I experienced?
 
You will see it most strongly on the high wear steels simply because you have to spend more time on the hone and use more pressure.

-Cliff
 
I can't get a burr to form on S30V (knife is a Native) using a Lansky coarse stone. I tried for about 30 minutes last night but I don't think it was there. I checked both visually and by dragging my fingers across the edge. Can someone tell me what I'm looking for? I'm beginning to think I need a diamond stone. Or am I forming the burr and just not noticing?
 
PerformanceFirst said:
I can't get a burr to form on S30V (knife is a Native) using a Lansky coarse stone. I tried for about 30 minutes last night but I don't think it was there. I checked both visually and by dragging my fingers across the edge. Can someone tell me what I'm looking for? I'm beginning to think I need a diamond stone. Or am I forming the burr and just not noticing?
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Go diamond ;)
 
@Cliff
Strange: I didn't use anything but the weight of DMT stone itself. I didn't experience any S90V sharpening trouble at all. But again, 59-60HRC and very special heat treatment by KW have last word here I guess.

@m-Wade
What knife?
 
daberti said:
Strange: I didn't use anything but the weight of DMT stone itself.
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It just gets more extensive at higher pressures as there is more friction.

PerformanceFirst said:
I can't get a burr to form on S30V (knife is a Native) using a Lansky coarse stone.
Click to expand...

Cut the edge of the knife into a stone until it can't slice paper. Sharpen one side of the bevel until it can. Repeat this process for the other side. Micro-bevel as desired to finish.

-Cliff
 
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