Can you use ceramics to sharpen s30/90/110v or not?

As an aside, I posed this question to @Nathan the Machinist so as to match the factory finish as much as reasonably possible before passing his work along to friends. 220 3M ceramic followed by a natural Arkansas stone appears to sharpen well enough for 4V and 3V at relatively high RC...
 
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I found the diamonds were not even that great to work with for just maintaining an edge on standard s30v or s35v blades, although they do work and will cut metal with enough time, patience, and consistent sharpening strokes. Due to the bonded nature of the abrasive, they are extremely bumpy and difficult to maintain a smooth continuous stroke across the bevel. I've seen other users post similar experience.

As a note, diamond stones like those are considered coated abrasives, not bonded. Bonded means lots of grains bonded together, like conventional aluminum oxide and silicon carbide stones. Bonded stones are where the abrasive has depth. Coated abrasives still use a binder of some kind, but it's only a thin surface layer of abrasive. Typical diamond stones are a coated abrasive with a metallic bond. :)
 
Personally if I have a knife that needs reprofiling I don't do it myself. I take the knife to a professional sharpener. The one I take it to uses Japanese waterstones and does a great job on any steel I've brought him so far.

He can set the edge to be easier for fixing up on they sharpmaker. After he sets it I just maintain it sharp. He flattens out convex edges or uneven grinds. He could even set it to a 30 degree angle so it will work easily with the SM jig.

Totally, I think your experience/feedback on using the SM diamonds for profiling is quite common. Definitely my experience too. It can be done, in the same sense that you "can" clean your driveway with a toothbrush. But there are more efficient ways. :)

Above, I was also thinking about just the notion of trying to use the SM diamond (or CBN, for that matter) rods for routine sharpening, like minor edge repair and apexing. My experience with doing that on the SM diamonds and S30/S35 Spyderco knives in my collection has been that it works, but it doesn't work great and still takes too long. The sharpening experience isn't good and it's harder to maintain a consistent stroke and edge bevel, for the same highlighted reason that you commented earlier in this thread. I attribute this at least partly to the nature of the coated abrasive.

I have the diamond rods for the sharpmaker and would not recommend them. The SM is an excellent system for touchups and making a knife that is already edge profiled properly much sharper. It is not a good system for reprofiling and grinding.

The experience I have with their diamond rods is that they are so coarse that it feels like my blade is skipping across the peaks of the pieces of grit. This causes the knife to skip and rattle in your hand as you try to use the diamond rods, making maintaining an angle nearly impossible.
 
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As a note, diamond stones like those are considered coated abrasives, not bonded. Bonded means lots of grains bonded together, like conventional aluminum oxide and silicon carbide stones. Bonded stones are where the abrasive has depth. Coated abrasives still use a binder of some kind, but it's only a thin surface layer of abrasive. Typical diamond stones are a coated abrasive with a metallic bond. :)

I actually meant "coated" and said "bonded", just a mental typo. :) Fixed in the earlier post, thanks. My point is that these SM diamond rods are NOT the same type of diamond sharpening surface as you get in a real diamond plate/stone, and this contributes to the uneven, inconsistent sharpening results due to the COATED nature of the abrasive, which makes it hard to maintain a smooth consistent stroke across your entire edge.
 
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As an aside, I posed this question to @Nathan the Machinist so as to match the factory finish as much as reasonably possible before passing his work along to friends. 220 3M ceramic followed by a natural Arkansas stone appears to sharpen well enough for 4V and 3V at relatively high RC...

If I understand his response, this is about finishing the blades, right? Meaning: to refine the edge after apexing. If so, that would be consistent what 42 and others are saying here on the role of sintered ceramics as a way to refine an edge.
 
So, trying to consolidate the responses to OP question on whether you can use ceramics to sharpen high vanadium super steels. By "sharpen" in the context of OP comments, I assume you are talking NOT talking about major profiling, you are talking about apexing and then finishing the edge. So these seem to be the combined answers:

1. Yes.
  • Why:
    • User reports from users of Sharpmaker rods, and other ceramic stones, that they can get their high vanadium steels sharp and it works.
    • SEM photos that suggest that AlOx and sintered ceramics can abrade high vanadium steels without any tear-out of the carbide material.
  • Recommendation: use ceramics for apexing AND finishing.
2. Yes, but it's not optimal and there are better options.
  • Why
    • Magnified photos that suggest AlOx and sintered ceramics cause excessive tear-out of the carbide material.
    • User reports that sharpening high vanadium steels on ceramics takes longer, takes more effort, and fails to get the edge as optimally sharp, compared to using materials such as diamonds or CBN.
    • User reports that for high vanadium steels sharpened on ceramic and experiencing carbide tear-out, the extra edge retention and wear resistance normally associated with these steels will be lost.
    • User reports that sharpening high vanadium steels on ceramics damages the ceramic stone by causing premature wear, and glazing. These negatively impact sharpening results and require the ceramic to be reconditioned.
    • User reports that for high vanadium steels sharpened on a damaged ceramic stone as above, the resulting edge will be merely burnished (polished) and not really sharpened.
  • Recommendation: use ceramics only for finishing after apexing on other materials, such as diamonds or cbn.

This a fair summary?
 
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Wow this thread is great, this is why I enjoy being a member at BF. Lots of great insight here around all facets of this issue! A few replies, lumped together.

(...)
David that all makes sense about SM being designed before the advent of super steels. They've tried to address the gap with diamond/cbn, but as many folks who use these know, they haven't quite nailed that part of the equation yet. At least, not IMHO as a user. I certainly don't attribute the lack of an "optimal" solution to super steels to anything sinister on Spyderco's part, they did after all release the diamond and cbn rods years ago to address this very thing. It just seems like they haven't worked that great. Also, I don't think most Spyderco average users have these add-on stones anyway, plus they don't realize that the included ceramic stones have the limitations with super steels that we're discussing in this thread. It seems like, for things to get better for those using SM to maintain super steels, they need some kind of improved strategy (best driven by Spyderco) to message HOW they should deal with super steels, and also, improved sharpening rod options. Absent that, it seems like SM users might be able to fall back on a solution something like what I indicated above in my reply to 42, some aftermarket stones that may cut better than the diamond/cbn, and then just using the ceramics in a very limited/niche role for light finishing work.

I think Spyderco could do themselves a big favor with other, finer grit options in diamond/cbn for the Sharpmaker. The small & narrow size of the hones, and the V-crock setup in general, sort of limit how effective the tool can be in heavy grinding tasks, even with their current ~400-grit diamond/cbn options. I don't think that's easily fixed, without completely starting over. Such tools aren't made for heavy profiling/grinding, when you get right down to it; they're just too small. If they really wanted to make best use of the same basic SM design, it'd be better-served at the refining end with something like a ~1200-grit (EF) diamond/cbn option, maybe even an EEF, and perhaps including an intermediate step in between 400 and 1200, such as a 600-grit option. I think then, with a similarly-rated grit alternative to the standard ceramics, the tool would really highlight the advantages of diamond/cbn where it counts most, at the finishing end, where it'll have the most obvious and distinct advantage in cleanly cutting/shaping the carbides in high-wear steels. I think they could win a lot of new fans of the Sharpmaker, this way.

To me, it seems obvious, if one knows diamond or cbn will do a better job in the initial grinding of high-wear steels, and you've gone to the trouble to provide that option for such a purpose, then finishing with diamond/cbn should yield obvious benefits as well on the same steels. I've always felt it's sort of pointless to finish with something that can't cut as cleanly as what's used to start the whole process in the first place. Since the SM is at it's best as a finishing tool, I think providing the optimum abrasive solution at that end of the spectrum is the smart way to go.


David
 
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Hoping that their upcoming Gauntlet system features the means and support for heavy grinding and rough shaping.
 
There is absolutely no evidence that carbide "tear out" ever occurs (unless you are using mud/slurry, but that is different process for metal removal).

Fair enough, modified the "Yes" response to the OP question in my summary. :)

The things I'm observing in reading this thread--and I'm pretty open minded to all of it--is that we don't have a ton of data available on any of these things. We have a few pictures, and anecdotal reports from folks (whose opinions I respect :)). I have limited experience myself sharpening these steels on Sharpmaker ceramics, on diamond stones, and on AlOx stones. It's all super interesting, but just in the end feels like we don't have enough data or systematic studies at hand to figure this out. I have to think there've been some academic materials science studies about all this, somewhere. I'll ping my brother-in-law, who's not a member of BF but is interested in all this kind of stuff and is a mat-sci researcher, and see if he has any additional info that could be of interest.
 
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I'd personally be very interested in seeing SEM imagery of a high-vanadium carbide edge prepared exclusively using aluminum oxide abrasives and worked thoroughly on sintered ceramic vs. an edge formed using diamond and only apexed on sintered aluminum oxide vs. one formed exclusively using diamond. I think the results would be fairly telling. :)

My hypothesis is that we'd see possible evidence of tearout with very rounded carbides standing proud of the steel on the first, a smooth apex on second, and a fully crisp but comparatively toothy/scratchy apex on the third. I could be totally wrong, but it's what I'd predict.
 
I'd personally be very interested in seeing SEM imagery of a high-vanadium carbide edge prepared exclusively using aluminum oxide abrasives and worked thoroughly on sintered ceramic vs. an edge formed using diamond and only apexed on sintered aluminum oxide vs. one formed exclusively using diamond. I think the results would be fairly telling. :)

My hypothesis is that we'd see possible evidence of tearout with very rounded carbides standing proud of the steel on the first, a smooth apex on second, and a fully crisp but comparatively toothy/scratchy apex on the third. I could be totally wrong, but it's what I'd predict.

Amen.
We have ekretz pics that cannot be discounted, they are as clear as a bell.

Also we have Tood's pics that are also clear as a bell. I have to make a comment here - s30v is the lowest end of Vanadium carbide rich steels that have "significant" carbide content. IDK about s110v performing as captured by the SEM. Even if it did, my own cut tests would indicate there is something not able to be quantified by imagery alone.

Test for yourself.

As for surface prep, even high VC steel can be cosmetically burnished - is not the same as sharpening.
 
So, trying to consolidate the responses to OP question on whether you can use ceramics to sharpen high vanadium super steels. By "sharpen" in the context of OP comments, I assume you are talking NOT talking about major profiling, you are talking about apexing and then finishing the edge. So these seem to be the combined answers:

1. Yes.
  • Why:
    • User reports from users of Sharpmaker rods, and other ceramic stones, that they can get their high vanadium steels sharp and it works.
    • SEM photos that suggest that AlOx and sintered ceramics can abrade high vanadium steels without any tear-out of the carbide material.
  • Recommendation: use ceramics for apexing AND finishing.
2. Yes, but it's not optimal and there are better options.
  • Why
    • Magnified photos that suggest AlOx and sintered ceramics cause excessive tear-out of the carbide material.
    • User reports that sharpening high vanadium steels on ceramics takes longer, takes more effort, and fails to get the edge as optimally sharp, compared to using materials such as diamonds or CBN.
    • User reports that for high vanadium steels sharpened on ceramic and experiencing carbide tear-out, the extra edge retention and wear resistance normally associated with these steels will be lost.
    • User reports that sharpening high vanadium steels on ceramics damages the ceramic stone by causing premature wear, and glazing. These negatively impact sharpening results and require the ceramic to be reconditioned.
    • User reports that for high vanadium steels sharpened on a damaged ceramic stone as above, the resulting edge will be merely burnished (polished) and not really sharpened.
  • Recommendation: use ceramics only for finishing after apexing on other materials, such as diamonds or cbn.

This a fair summary?

Check out point number two under Yes #1 and point number 1 under Yes #2, they contradict eachother.

One saying AlOx can sharpen with minimal carbide tear out and the other says AlOx causes excessive tear out.
 
I am willing to donate a Mule Team 26 PMA11 purchased and shipped direct from Spyderco to a prospective SEM shootout so long as we aim for an XXF DMT versus SPS II 3K showdown. If ToddS is willing and has said plate and stone available, of course. Unless someone has another stone in mind...
 
What does the heat treatment do to effect the hard carbides and or the matrix they are carried in? Say a soft vs hard hrc. Does this effect the tear out at all?

Also was thinking about the pressure used and weather hard or soft alox is used?

I used to use ceramic and it def got lots of build up reducing its effectiveness. But it did get knives a bur. I used it for touch ups only. Great for vg10. Was easy to use it to remove chipping from my s90v 940-1. But haven't really used it much after to say how different it was in retention to diamonds alone.
 
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What does the heat treatment do to effect the hard carbides and or the matrix they are carried in? Say a soft vs hard hrc. Does this effect the tear out at all?

Also was thinking about the pressure used and weather hard or soft alox is used?

I think they were talking specifically about AlOx as appears in the sharpmaker stones. Light pressure is best because it helps keep burring down. The abrasives should always be the ones doing the grinding, not pressure.
 
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Or maybe we could do XXC DMT versus Naniwa Green Stone (Silver Lobster) #120. See how diamonds compare to SiC at the coarse end of the spectrum.
 
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