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

[FortyTwoBlades]

Again, this is just a hypothesis, but I believe that if a bonded abrasive of anything below "hard" bond, like a medium-soft water stone, was used for the primary shaping work then you'll be more prone to tearout when moving to a sintered ceramic. The thing is that carbides in steel are sort of like rocks in plaster. If the plaster is abraded down against pavement, you end up with the rocks being the only thing that even makes contact. But if the surface is soft enough to wear micro-grooves in it that enable the spaces between the carbides to be abraded then you have the situation where poorly supported carbide "peninsulas" can form. When subjected to the high lateral pressure that sintered ceramics can easily proved, you'd be likely to either tear them right off or roll them over. However, on a hard Norton India, for instance, before moving to the sintered ceramic, you'd be much less likely to encounter that phenomenon, and would instead just be glazing the India stone a bunch rather than causing the carbides to stick way out. Could be wrong, but that's what I'd guess would happen.

 

[HeavyHanded]

As a last thought on this, the conversation is a little sidetracked by the possibility of carbide tearout and on what steels/abrasives this occurs.

To me this is a secondary consideration to how well ceramic actually preps the edge at the finishing stage. You could just do a survey of materials people prefer to finish high vanadium steels and why.

 

[FortyTwoBlades]

I personally greatly enjoy using sintered ceramics for a light final apexing stage on all steels, but the key is that pressure is light and the number of strokes small. It's an expensive material for how little you end up actually using it, but worth it, in my opinion, for how nicely it finishes up a properly prepped edge.

 

[maximus83]

I personally greatly enjoy using sintered ceramics for a light final apexing stage on all steels, but the key is that pressure is light and the number of strokes small. It's an expensive material for how little you end up actually using it, but worth it, in my opinion, for how nicely it finishes up a properly prepped edge.

Will try your suggestion 42, with a couple of my super steel folders. As in: sharpen on diamonds 300 > 1200, then hold the Spydie UF rods in hand, and do a few super light final strokes at the same sharpening angle.

Q's on this:

• Think the UF will make a significant sharpening difference, used like this?
• For those who prefer micro-bevels (currently not me, but considering it as I see the benefits as described by HeavyHanded and others elsewhere): does it make sense to create the micro-bevel first on the diamonds, THEN refine it on the UF? Or, should I actually use the UF to CREATE the micro as the last step?

 

[maximus83]

As a last thought on this, the conversation is a little sidetracked by the possibility of carbide tearout and on what steels/abrasives this occurs.

To me this is a secondary consideration to how well ceramic actually preps the edge at the finishing stage. You could just do a survey of materials people prefer to finish high vanadium steels and why.

Agree this would be a useful data point, and a lot less complicated/expensive to find out. But on this question, the OP originally asked about "sharpening" (by which I assume, he means actual apexing AND finishing) on ceramics. Here, you're saying "finishing stage", and there are definitely some pro makers and sharpeners who will finish on ceramics. And I know some of the popular guided systems, like WE for example, will include some high-grit ceramic stones for finishing. And @adamlau indicated Nathan the Machinist does this. But my point here is, do we just want to know who FINISHES on ceramic, or do we actually want to know if there are folks out there who SHARPEN (apex) on ceramic? Is the controversy around FINISHING on ceramic, or APEXING on ceramic?

 

[HeavyHanded]

Agree this would be a useful data point, and a lot less complicated/expensive to find out. But on this question, the OP originally asked about "sharpening" (by which I assume, he means actual apexing AND finishing) on ceramics. Here, you're saying "finishing stage", and there are definitely some pro makers and sharpeners who will finish on ceramics. And I know some of the popular guided systems, like WE for example, will include some high-grit ceramic stones for finishing. And @adamlau indicated Nathan the Machinist does this. But my point here is, do we just want to know who FINISHES on ceramic, or do we actually want to know if there are folks out there who SHARPEN (apex) on ceramic? Is the controversy around FINISHING on ceramic, or APEXING on ceramic?

You will have a heck of time sharpening anything but the thinnest of blade stock with corresponding thin cutting bevels, using ceramics on stuff like s110v or CPM 10V. You can rough grind them with just about any manufactured abrasive, but once you get to a finer size abrasive action wth hard ceramics it will be a whole new ball game.

I guess you could do two surveys...

 

[maximus83]

You will have a heck of time sharpening anything but the thinnest of blade stock with corresponding thin cutting bevels, using ceramics on stuff like s110v or CPM 10V. You can rough grind them with just about any manufactured abrasive, but once you get to a finer size abrasive action wth hard ceramics it will be a whole new ball game.

I guess you could do two surveys...

Ok so this is interesting, just realized we have more than one issue in this thread. To be clear, I'm not personally interesting in sharpening on ceramic, went down that road years ago with SM, and got off that train. But that's what I thought the OP was asking. Not sure if there are a lot of people out there still trying to actually sharpen on ceramic. There are DEFINITELY a lot of SM users with super steels who are using their SM ceramics to at least try to sharpen those blades, so if they shouldn't be, it seems like somebody should be letting them know (preferably Spyderco).

On the point you made: sounds like you are even questioning the idea of FINISHING on ceramic. This, I know nothing about. and am just going to test it per 42's approach. Willing to try and see what happens. So you think that even finishing on ceramic is not worth it, and gets subpar results?

 

[FortyTwoBlades]

Will try your suggestion 42, with a couple of my super steel folders. As in: sharpen on diamonds 300 > 1200, then hold the Spydie UF rods in hand, and do a few super light final strokes at the same sharpening angle.

Q's on this:

• Think the UF will make a significant sharpening difference, used like this?
• For those who prefer micro-bevels (currently not me, but considering it as I see the benefits as described by HeavyHanded and others elsewhere): does it make sense to create the micro-bevel first on the diamonds, THEN refine it on the UF? Or, should I actually use the UF to CREATE the micro as the last step?

I find that it greatly assists in providing a crisp apex, but I'd say if you're running a microbevel to stick with just one stone for the task. If using the ceramic you'll essentially only be putting the micro on the steel/chromium carbide components, not the vanadium carbides, though (of course) there will be some infinitesimally small degree of abrasion to them, it will be so minimal as to be insignificant.

To be clear, in virtually all sharpening work, I do less than ten passes per side on sintered ceramics as a final stage.

 

[HeavyHanded]

On the point you made: sounds like you are even questioning the idea of FINISHING on ceramic. This, I know nothing about. and am just going to test it per 42's approach. Willing to try and see what happens. So you think that even finishing on ceramic is not worth it, and gets subpar results?

I have smooth steeled regular D2 to a hair whittling edge. I have gotten s110v to whittle hair using silicon carbide honing compound on a paper strop following a full sharpening on silicon carbide wet/dry. I have sharpened 440c on a soft Arkansas to tree-topping sharp. Would I recommend any of these strategies as a good way to tackle these steels - NO.

I have a simple rule that I picked up from Jason B and verified for myself many times by attempting to use other abrasives and comparing the results - once the Vanadium content gets to 4% or higher I switch to diamonds if sharpening above a coarse/medium grit finish. In practice I switch to diamonds on many high carbide steels whether it be Vanadium or not simply because it works faster and my results are more consistent, requiring less QC.

Based on my own testing I added diamond dust to my honing compound specifically to address the high Vanadium steels - just enough to get the job done and not too much that it hampers the results on lower carbide stainless and carbon steels. I wouldn't have done this if I wasn't 100% convinced of the necessity.

Ultimately if people really like the ceramics they are going to find ways to make it work no matter, just like I did with a smooth steel on D2. If I felt the ceramics did something for me on these steels that I couldn't achieve more reliably with other means, I'd use the ceramics too.

As a side note, you have to remember that s110v and 10V have more than 2x the carbide density of s30v. You almost cannot lump them in the same class.

 

[maximus83]

Cool, thanks for the background.

 

[Chris "Anagarika"]

I have smooth steeled regular D2 to a hair whittling edge. I have gotten s110v to whittle hair using silicon carbide honing compound on a paper strop following a full sharpening on silicon carbide wet/dry. I have sharpened 440c on a soft Arkansas to tree-topping sharp. Would I recommend any of these strategies as a good way to tackle these steels - NO.

I have a simple rule that I picked up from Jason B and verified for myself many times by attempting to use other abrasives and comparing the results - once the Vanadium content gets to 4% or higher I switch to diamonds if sharpening above a coarse/medium grit finish. In practice I switch to diamonds on many high carbide steels whether it be Vanadium or not simply because it works faster and my results are more consistent, requiring less QC.

Based on my own testing I added diamond dust to my honing compound specifically to address the high Vanadium steels - just enough to get the job done and not too much that it hampers the results on lower carbide stainless and carbon steels. I wouldn't have done this if I wasn't 100% convinced of the necessity.

Ultimately if people really like the ceramics they are going to find ways to make it work no matter, just like I did with a smooth steel on D2. If I felt the ceramics did something for me on these steels that I couldn't achieve more reliably with other means, I'd use the ceramics too.

As a side note, you have to remember that s110v and 10V have more than 2x the carbide density of s30v. You almost cannot lump them in the same class.

Can’t be more objectively subjective than this. Basically what works for one

What’s best to tackle BM D2? DMT EEF edge leading without any ceramics? Or few swipes on Spyderco UF useful?
I got it sharp but it’s not VG10 sharp. Similar problem with my S110V, though D2 & S110V at my best seems to behave differently but both below VG10 level (that i can achieve).

 

[HeavyHanded]

Can’t be more objectively subjective than this. Basically what works for one

What’s best to tackle BM D2? DMT EEF edge leading without any ceramics? Or few swipes on Spyderco UF useful?
I got it sharp but it’s not VG10 sharp. Similar problem with my S110V, though D2 & S110V at my best seems to behave differently but both below VG10 level (that i can achieve).

For D2 I have two very different strategies.
- Norton Crystalon and strop on Washboard with stock compound. Embrace the big carbide slice effect and grind the edge thin to help with pressing cuts - 26° or so.

- Or I use diamond up to a coarse or fine and then microbevel on EEF, followed by a couple of light swipes on WB paper/compound. I use this strategy a lot on many higher carbide steels, limiting the EEF to just enough to refine a little but not enough to eliminate all the edge variation.

VG10 is very fine grained, if shooting for a real smooth cut with D2 I'd take it up to an EF and then microbevel on EEF. It might not hold up as long as other means, but should turn out screaming sharp while it lasts and default back to a nice EDU edge for a good long while.

 

[BluntCut MetalWorks]

Effectiveness of apex steeling/aligning depend on matrix ductility/plasticity range. In other words, how far steel supports bend & flow without fracture. If force to choose a steeling medium, I would use smooth spring coil 48-51rc or some smooth metal with hrc between 30-50rc. Where smooth-steel ~61rc, glass 60-63rc, ceramic ~70+rc. Idea is to burnish/smear with low impulse force (minimize impact force).

More carbide = faster work-hardening by plastic flow. Big carbide moves/flows less because of piling-up, envision a snow shoe.

 

[Chris "Anagarika"]

Martin, Luong,

Thanks. Insightful advice!

 

[maximus83]

I find that it greatly assists in providing a crisp apex, but I'd say if you're running a microbevel to stick with just one stone for the task. If using the ceramic you'll essentially only be putting the micro on the steel/chromium carbide components, not the vanadium carbides, though (of course) there will be some infinitesimally small degree of abrasion to them, it will be so minimal as to be insignificant.

To be clear, in virtually all sharpening work, I do less than ten passes per side on sintered ceramics as a final stage.

Sharpened S30v on diamond 300 > 1200. Shaving sharp. Then 5 passes each side, super light at sharpening angle on Spyderco UF rods. This made it sharper, would tree-top hair and push cut entirely through pieces of newsprint top to bottom.

ETA: Did another blade, an S35vn this evening. This one on new DMT XC > C > EF folding sharpeners. Tested, shaving sharp. Finished on Spydie UF, as above. Same result, even sharper.

Same approach on a soft Chinese stainless folder. DMT C > EF. Finish on UF ceramics. Same result. Starting to look like a pattern. Granted this last is not about high-vanadium steels but just about finishing with a ceramic.

Now I wish I could understand what's going on and what I actually did. I hate doing stuff and I don't get why it worked.

 

[HeavyHanded]

Sharpened S30v on diamond 300 > 1200. Shaving sharp. Then 5 passes each side, super light at sharpening angle on Spyderco UF rods. This made it sharper, would tree-top hair and push cut entirely through pieces of newsprint top to bottom.

ETA: Did another blade, an S35vn this evening. This one on new DMT XC > C > EF folding sharpeners. Tested, shaving sharp. Finished on Spydie UF, as above. Same result, even sharper.

Same approach on a soft Chinese stainless folder. DMT C > EF. Finish on UF ceramics. Same result. Starting to look like a pattern. Granted this last is not about high-vanadium steels but just about finishing with a ceramic.

Now I wish I could understand what's going on and what I actually did. I hate doing stuff and I don't get why it worked.

Light abrasion combined with some burnishing/plastic flow.

Examine closely - as with smooth and fine-toothed steels, ceramics have a tendency to make very small, sharp burrs.

 

[BluntCut MetalWorks]

I see evidences of burnished & plastic flowed - edge lean side to side from center line and wispy apex respectively. Assessment whether this result is beneficial or degradation depend many complex variables.

Never hopelessness... let's confine burnish & plastic-flow as compress and stretch, thus translated to work-hardened. Now for better envisioning, it takes equivalent physical form of compressed & stretched spring - aha, loaded spring = higher potential energy(PE). Expected properties:

1. harder compress or stretch further into even higher PE.
aha, resistance to move until force exceed PE.

2. impact load = yield - PE.
e.g. envision about tapping a highly compressed/stretched spring or cable with a sharp carbide edge. Fun things often occurs.

3. unbounded PE will release E to lower PE state. *e.g. just let go of elastic compressed/stretched spring from hands pressure.

Pressing my lucks - extrapolating properties 1 to 3 to knife edge.

1. ppl have been utitilize work-hardened edge for a long time. e.g. H1 today.

2. OK - a highly generalize based on steel matrix crystal phase remain unchanged at this PE level. Mean, higher dislocation = lower impact load. Not a good ideal to bring stressed edge to chopping competition.

3. Apex will widen with age. wag est for widening width curve = Wc*PE/time^2. Where Wc - handwave physics - is distance of crystal movement probability constant. Integrate time zero to infinity, your edge goes back to pre compress & stretch width. OK let me push my luck even further... in space, how many days would a s30v 200nm wide apex 7.5dps - formed via edge trailing ceramic burnished & stretched - stays below 250nm? definitely less than 1 day because I wag so

Unless one can shape/form steel edge via light sabre or dematerializer, there will be some level of compress & stretch. Anecdotal data - Fixed diamond/cbn on avg has lower C&S than ceramic.

 

[maximus83]

Light abrasion combined with some burnishing/plastic flow.

Examine closely - as with smooth and fine-toothed steels, ceramics have a tendency to make very small, sharp burrs.

So: my 'refining' with the Spydie UF didn't truly refine the edge, it either just polished it, or made a really small/sharp burr. Either way, this enabled it to APPEAR to be more sharp by performing parlor sharpness tricks. But you believe this edge is ultimately not durable and will not perform any better--or perhaps even as well--as if I had just stopped with the DMT EF stage, or perhaps the DMT EF with some regular stropping afterwards?

 

[HeavyHanded]

So: my 'refining' with the Spydie UF didn't truly refine the edge, it either just polished it, or made a really small/sharp burr. Either way, this enabled it to APPEAR to be more sharp by performing parlor sharpness tricks. But you believe this edge is ultimately not durable and will not perform any better--or perhaps even as well--as if I had just stopped with the DMT EF stage, or perhaps the DMT EF with some regular stropping afterwards?

It definitely refined it more.
- polished with finer abrasive = more refined
- steeled to plastic flow, increased uniformity of edge = more refined
- mix of fine abrasion and plastic flow = more refined

It might very well out perform or perform equally well as any other final finishing method, I am not implying any parlor trickery. I only bring up possibility of burring as I find ceramics to be almost unique in their ability to make small burrs that actually cut well - whittling hair in some cases. I attribute this to the burnishing factor, as smooth-steeled edges can sometimes behave similarly for the same reason.

IF this is the case longevity will suffer. If it is not the case it should hold up as well as any other method.

Ultimately the level of refinement you apply to an edge should have more to do with intended use than any other factor, but hey - ease of maintenance is also a big factor that for me, often trumps other considerations.

 

[maximus83]

Unless one can shape/form steel edge via light sabre or dematerializer, there will be some level of compress & stretch. Anecdotal data - Fixed diamond/cbn on avg has lower C&S than ceramic.

Hey Bluntcut, thanks for that, I'm struggling a bit to interpret. So in short, you're saying that anecdotally, you think diamond/cbn material works better even for finishing super steels than ceramic does. Right?