S35VN sharpening issues

I usually judge steel by the Vanadium content, at 4% Vanadium with a manufacturer recommended Heat Treatment protocol most stones that are not diamond stones tend to have problems. The HT can greatly affect the stones ability to sharpen any specific steel so there will be exceptions.

High quality ceramics like the Shapton Glass handle these steels much better but as you get into the really high class of steels with 9% or more Vanadium its pretty much a must to switch to diamond plates. The difference in the finished edge becomes very noticeable at this point.
 
I am not entirely sure that just because aluminum oxide is softer than vanadium or niobium carbide that means it is unable to sharpen steels with higher vanadium content like s35vn. In fact the carbides are quite small and the steel matrix they sit in is not too hard to be sharpened by the aluminum oxide stones. I have no problem touching up almost any steel on my sharpmaker rods, which I do free handed without the jig. However I have to make sure not to let the knife get too dull or it is virtually impossible to sharpen with the sharpmaker stones. If I just make sure to always touch up the edge when it gets abit dull it does fine.

Now let me explain why I believe aluminum oxide can sharpen steels with vanadium carbides in it. It is true that the aluminum oxide stones cannot cut the vanadium carbide, but as they are so small it doesn't matter they are not being cut. They simply get torn out as the steel matrix they sit in is worn away by the aluminum oxide stones. I am not sure if this is true, it is just a theory, but how else would you explain being able to touch up high vanadium content steels on my sharpmaker stones. I agree diamond stones will actually cut the vanadium carbides themselves while the aluminum oxide stones will not.
 
Most any stone will sharpen any steel to a point. 1000 grit is about that point and coarser stones fair even better.
 
In my understanding as a non metallurgist, carbides formed during power processing have an average diameter of ~10 micron. Therefore, the grit size of abrasive may not matter up until this point, which is, as Jason B. wrote, #1,000 (ANSI) or #600 (EP stone).


Miso
 
Jason B. said:
Shapton stones are Ceramic abrasive.
Click to expand...

Just an FYI for my homies

SiC, Alumina, CBN, Etc

They are all Ceramic Abrasives.

its like ice cream and gelato,

Gelato is still ice cream

we just call the fancy Ceramics, "Ceramic"

Ceramic is not a thing in itself, there in no Ceramic element on the periodic table :D
 
DeadboxHero said:
Just an FYI for my homies

SiC, Alumina, CBN, Etc

They are all Ceramic Abrasives.

its like ice cream and gelato,

Gelato is still ice cream

we just call the fancy Ceramics, "Ceramic"

Ceramic is not a thing in itself, there in no Ceramic element on the periodic table :D
Click to expand...


You are correct sir! A ceramic is an inorganic, non metallic Oxide, Nitride or Carbide material. Usually crystalline in nature.
 
hahaha bout had my head explode trying to figure out what ceramic was as it pertains to waterstones felt like I was trying to figure what electrolytes do in Brawndo :D :D :D
 
I think the point of discussion was that any of those ceramics may not be hard enough to work well on vanadium carbides, even silicone carbides. Diamond is definitely harder than vanadium carbides and therefore preferable. However, this is only meaningful when one to polish the steel above #1,000 (ANSI) or below 10 micron (#600 EP and #1,500 Shapton equivalent), as Jason B pointed out.


Miso


Added: Ceramic stones of cubic boron nitride may be hard enough to polish vanadium carbide. I do not know what abrasives they use in Shapton glass stones, though.
 
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DeadboxHero said:
Just an FYI for my homies

SiC, Alumina, CBN, Etc

They are all Ceramic Abrasives.

its like ice cream and gelato,

Gelato is still ice cream

we just call the fancy Ceramics, "Ceramic"

Ceramic is not a thing in itself, there in no Ceramic element on the periodic table :D
Click to expand...

So, technically speaking, EP stones are ceremic stones as well?


miso2 said:
I think the point of discussion was that any of those ceramics may not be hard enough to work well on vanadium carbides, even silicone carbides. Diamond is definitely harder than vanadium carbides and therefore preferable. However, this is only meaningful when one to polish the steel above #1,000 (ANSI) or below 10 micron (#600 EP and #1,500 Shapton equivalent), as Jason B pointed out.


Miso


Added: Ceramic stones of cubic boron nitride may be hard enough to polish vanadium carbide. I do not know what abrasives they use in Shapton glass stones, though.
Click to expand...

I was just about to ask what type of ceramic Shapton was. Anyone know? I tried a bit of googling before i typed this up, found zilch on their website.


I kinda had the same problem doing N690 this afternoon. I used Aluminium Oxide stones the whole way, finishing on 3000 EP polishing tapes. It sliced well and smooth, but lost bite. Couldn't pushcut newsprint. I redid the edge by going back to SF diamond stone, and really lightly gliding on the 3000 EP tapes. I found the latter had better results. I did deburr after the SF diamond just to see how it performed. It had amazing bite, and for the most part, would already be an excellent edge for outdoor usage (camp knife). But we aren't satisfied with that are we? I'll have to make do with what i have until my new stuff arrives.
 
Yes, its all ceramic but there are different grades, they will never be as hard as diamond or CBN but they can be harder and softer relative to each other.

The abrasive and its hardness, structure, shape, size is one component to a sweet sharpening stone, its more about the total package, the abrasive volume, porosity, bond type, bond strength

just like knife steel, its the heat treat and geometry that are important too.

The factors I mentioned above translate to the cutting speed, tactile feedback, loading/glazing, dishing, need to dress, slurry release, polishing, burnishing, plowing, etc


The Shaptons are Alumina Ceramic based with high abrasive volume in a hard resinous type bond

The exact make up and process is trade secret, besides the matrial science would only tell you so much, they just need to be used to see the synergy with all the variables.

My only experience is with a borrowed 30,000 Shapton pro bench stone which is somewhat of a novelty item for the tools I sharpen and the price of that stone.

They work like Naniwa Pros or better or worse depending on your preferences and opinions.

They are generally for people that like polished edges with nicer finishes,

Otherwise keep it toothy and strop on compounds.

Or do whatever :p:D

Ive used special diamond waterstones other then the already exotic Naniwa diamond waterstone, I like them but I'd have a hard time telling everyone that they need that because its super duper! :D haha

Its just like the whole "do I need a supersteel?" argument.

Does one need a $400 pure superabrasive diamond waterstone? maybe, maybe not.
For Joe Average, no

for a professional freehand knife sharpener or extreme hobbyist sure, its nice but it won't make you a better sharpener and probably more of a "want" then a "need"



But heck yea I like em :D wish there were more of them and more demand so the price would go down somehow jeez
 
Securis said:
So, technically speaking, EP stones are ceremic stones as well?




I was just about to ask what type of ceramic Shapton was. Anyone know? I tried a bit of googling before i typed this up, found zilch on their website.


I kinda had the same problem doing N690 this afternoon. I used Aluminium Oxide stones the whole way, finishing on 3000 EP polishing tapes. It sliced well and smooth, but lost bite. Couldn't pushcut newsprint. I redid the edge by going back to SF diamond stone, and really lightly gliding on the 3000 EP tapes. I found the latter had better results. I did deburr after the SF diamond just to see how it performed. It had amazing bite, and for the most part, would already be an excellent edge for outdoor usage (camp knife). But we aren't satisfied with that are we? I'll have to make do with what i have until my new stuff arrives.
Click to expand...


It is surprising to me that they use zirconia, of which Knoop hardness is around 1,200. Can you provide the link? I am curious.

Regarding edge finish, I like a kind of finish you described. Good bite for a better edge longevity and enough refinement for push cutting. What I do to get this, I set the edge with a #400 silicone carbide stone and then deburr with #600 and #1,000 very lightly (or with diamond suspension on a 2,000 EP tape for S35VN) followed by stropping.


Miso
 
Its just like the whole "do I need a supersteel?" argument.
Click to expand...

At this point, based on my slight, obsession with sharpening, the answer is a definite yes. hahaha!

At this point in time, i'm a bit unsure about my skill level, and how to improve upon it. I'm using the Edge Pro as a guided system now as it is work/business related. I am keen on doing freehand on a recreational basis, but that would come later. Perhaps i'll give the search function a bit of use after this.
 
Yeah, I became a "steel snob" rather early on. And just never shook it. For 2.5 years I have only used CPM3V & CPM20CV to make any of my knives at this point. Good thing is, when you get comfortable working with & sharpening the steels with high levels of Vanadium and/or Tungsten, normal steel like D2, 1095, 154 & A2, seem like soft butter to sharpen! It actually makes me double check when I'm working with any of these, as well as many others. I'll a actually say to myself, "is this really D2? It's SO soft!" Kinda funny.
 
DavidHoback said:
Yeah, I became a "steel snob" rather early on. And just never shook it. For 2.5 years I have only used CPM3V & CPM20CV to make any of my knives at this point. Good thing is, when you get comfortable working with & sharpening the steels with high levels of Vanadium and/or Tungsten, normal steel like D2, 1095, 154 & A2, seem like soft butter to sharpen! It actually makes me double check when I'm working with any of these, as well as many others. I'll a actually say to myself, "is this really D2? It's SO soft!" Kinda funny.
Click to expand...

The same thing happened to me. My first knife was AUS8, second knife was s30v. It was a steep slippery slope from then on. i remember back 4 or 5 years, D2 was like, really hard, in Malaysia at any rate. Now, like you say, butter.

There was one steel in particular though, that was really hard to wear away - Sliepner. my 220 aluminium would just tickle the blade.
 
miso2 said:
It is surprising to me that they use zirconia, of which Knoop hardness is around 1,200. Can you provide the link? I am curious.

Regarding edge finish, I like a kind of finish you described. Good bite for a better edge longevity and enough refinement for push cutting. What I do to get this, I set the edge with a #400 silicone carbide stone and then deburr with #600 and #1,000 very lightly (or with diamond suspension on a 2,000 EP tape for S35VN) followed by stropping.


Miso
Click to expand...

'Zirconia' is probably a reference to Zirconia-Alumina.

By itself, zirconia (ZrO[sub]2[/sub]) is not very hard, as you've noted, and I don't think it's generally known or used by itself as an abrasive. In this case, the abrasive grit is likely alumina (aluminum oxide at ~ 2100 Knoop). Zirconia is added to the ceramic recipe to toughen it, making the grit more durable, i.e., less brittle, less friable and therefore less prone to breaking down as quickly as straight aluminum oxide. This toughness-enhanced characteristic is touted by manufacturers of Zirconia-Alumina grinding belts, which are supposed to be longer lasting than conventional aluminum oxide belts. I purchased one of these belts, which is why I looked into it, to see what's different about zirconia-alumina. They do seem to be pretty durable, FYI. ;)


David
 
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Securis said:
So, technically speaking, EP stones are ceremic stones as well?




I was just about to ask what type of ceramic Shapton was. Anyone know? I tried a bit of googling before i typed this up, found zilch on their website.


I kinda had the same problem doing N690 this afternoon. I used Aluminium Oxide stones the whole way, finishing on 3000 EP polishing tapes. It sliced well and smooth, but lost bite. Couldn't pushcut newsprint. I redid the edge by going back to SF diamond stone, and really lightly gliding on the 3000 EP tapes. I found the latter had better results. I did deburr after the SF diamond just to see how it performed. It had amazing bite, and for the most part, would already be an excellent edge for outdoor usage (camp knife). But we aren't satisfied with that are we? I'll have to make do with what i have until my new stuff arrives.
Click to expand...


I emailed Shapton regarding the abrasives used in their glass stones. While they did not give me the details, the answer was alumina-based abrasives. Could be Zirconia-toughened alumina.


Miso
 
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