Sharpening Plateau

[rollintent]

I seem to have reached a plateau in my sharpening game. I have been focusing on a spyderco S30V delica lately but the same applies to all blades Ive been working on lately. I get the best results raising a bur on both sides with my diamond stones ending in extra fine DMT then either going to a Fine white ceramic followed by a spyderco Extra fine ceramic stone. I raise a bur on both sides with each stone then alternate sides of the blade with each stroke to remove bur. I have tried all kinds of strops and compounds including green compound, diamond sprays from 1.0 down to .25 micron, on balsa, basswood, and leather including bare leather with no compound at all. I rarely see an improvement of my edge from stropping and when I do it is minimal. Far more often than not it degrades my edge coming off the extra fine ceramic. I am getting near hair whittling edges meaning if I drag the right hair across the right part of the blade and hold my tongue just right I can get it to whittle and or cut through a hair by pulling it across the blade. I just cant get to that edge where I can consistently drag a hair across the blade and it whittles consistently and eagerly. Ive also tried taking my blade to a 6000 and 16000 grit shapton combination pocket stone that Sharpening supplies was selling a while back and it only degrades my edge from what I am achieving off the extra fine spyderco ceramic whetstone. Any guesses what I may be missing that is keeping me from breaking through to my goal? I even got very close to being able to push cut a zig-zag cigarette paper last night but not real easily.

 

[Your Cut Finger]

Same for me. Stropping, no matter how light or few seems to be a step back.

 

[Obsessed with Edges]

For attaining and keeping a hair-whittling edge on S30V, ditch the ceramics and the green compound, for starters. Neither of them will work to fully thin, shape and refine the vanadium carbides in the steel. Ceramics can sort of maintain it for a while after setting a fresh, crisp new edge on diamond; but they'll eventually burnish & round off the apex, creating the issues you describe. And green compound is essentially useless on S30V and similar wear-resistant steels.

When refining S30V and similar steels with fairly heavy vanadium content (4% or more), diamond or cbn is the way to go, as they're the only abrasives capable of fully and efficiently cutting the vanadium carbides. See the hardness values below.

Thinning the edge geometry to 30° inclusive or less also makes hair-whittling sharpness a lot simpler.

Hardness of materials involved:
Diamond = 7000 Knoop
CBN (cubic boron nitride) = ~ 4500 Knoop
Vanadium carbide = ~ 2800 Knoop
Alumina ceramic (aluminum oxide) = ~ 2100 Knoop
Green compound (chromium oxide) = ~ 1400 Knoop

 

[rollintent]

Are you saying my best chance at a hair whittling edge is directly off my extrafine diamond stone? I have been under the impression that I’ll need something much finer than my extra fine DMT to get hair whittling. Do I need to go from extra fine DMT to diamond stropping spray on basswood or balsa maybe?

 

[Obsessed with Edges]

Are you saying my best chance at a hair whittling edge is directly off my extrafine diamond stone? I have been under the impression that I’ll need something much finer than my extra fine DMT to get hair whittling. Do I need to go from extra fine DMT to diamond stropping spray on basswood or balsa maybe?

That's the key.^

After your EF DMT, use diamond or cbn compounds on a hard strop for best results. I personally prefer basswood for use with them. Diamond compounds at 3 micron and finer work very, very well on S30V.

 

[wootzblade]

I seem to have reached a plateau in my sharpening game. ... I get the best results raising a bur on both sides with my diamond stones ending in extra fine DMT then either going to a Fine white ceramic followed by a spyderco Extra fine ceramic stone. I raise a bur on both sides with each stone then alternate sides of the blade with each stroke to remove bur. ....

The part I've highlighted in bold is where you make it wrong, I believe.
Having raised the burr on the extra fine DMT, we move to the deburring.
At the base of a burr raised on CBN or Diamond grit about #1000 (and the extra fine DMT has grit #1200) you've already got a razor sharp edge - you need only to expose it by deburring.

By repeatedly raising burrs on the Spyderco Fine Ceramic bench stone, and then the Spyderco Ultra Fine, you dull the edge apex. You may think that by doing so you refine the edge, nope - you grind the apex off, thickening it.

In line with that advised by Obsessed with Edges we go to a 5 microns abrasive to deburr; but many go straight from #1000 to either 3 microns or 1 microns.
And yes, as he says, CBN or diamond is the best for that steel.
But if your blade responds to the ceramic stones, try deburring on the Spyderco Fine Ceramic bench stone (6 micron grains), followed by the Spyderco Ultra Fine (3 micron).
Irrelative to the steel, you should be doing it differently - after the grit #1000 you should only minimize the existing burr, not raise a new one.

E.g. try to remove the majority of the burr working just the side with the burr on your Fine Ceramic, and as you near the apex (but haven't reached it yet), switch to the Ultra Fine stone and finish the deburring by alternating sides, carefully watching not to overhone the edge apex itself.
You will get a hair-splitting edge sooner than it takes me to type all this.

 

[Megabassx7]

Diamond on balsa is what i use. I’ve had vg10 Delicas and pm2 in 30v breaking hairs off the dmt extra fine so I know it can be done with a bit more refinement and nearly impossible lightness of touch. With diamonds the lighter the touch the better

 

[wootzblade]

Exactly so.

rollintent - try to visualise what is happening to the edge apex.
The very edge adjacent to the burr you've raised on the #1200 DMT has the apex width in the vicinity of 0.1-0.2 micron.
When you rub it against the 6 micron grains on the Spyderco Fine Ceramic bench stone, to raise another burr as you say, you shift lots of metal from the apex to the side of the blade.

Below is an oversimplified modelling of what is happening during sharpening.

SEM image by courtesy of Todd Simpson scienceofsharp.wordpress.com

1 - the burr is raised by grinding one side, at this stage you even out the bevel
2 - you start grinding the other side and evening out the bevel
3 - the burr is raised on the other side
4 - you minimise the burr by grinding with minimal pressure
Then deburr

The next picture shows what happens when you repeatedly raise the burr overgrinding the apex:

The resultant edge apex width is shown by the yellow horizontal line.

Generally, the abrasive grit #1000 is where you raise a fine burr, upon removing which you get a true razor sharp edge.

 

[Wowbagger]

Any guesses what I may be missing that is keeping me from breaking through to my goal?

Allow me to channel Sherlock Holmes for a moment :

My dear fellow . . . I NEVER GUESS.
Get an Edge Pro Apex. Put diamond stones in it. If you can find (or make as I have) one with 8,000 grit all the better.
Oh . . . and do ignore the strops. All you require can be had off a stone properly applied.

 

[wade7575]

If you want good CBN or Diamond emulsions for stropping contact this guy he has CBN and Poly and Mono diamond,the Poly diamond has more facet's meaning more edge's and cut's faster but they wear down faster Mono diamonds are flat like plates and wear longer but do not cut as fast,I use Kens stuff with great success and you get a 4oz bottle as well.I don't bother with the sprays as I feel you waste to much.

https://www.facebook.com/ken.schwartz.984/about?lst=100003248825433:100001212185481:1519281298

I seem to have reached a plateau in my sharpening game. I have been focusing on a spyderco S30V delica lately but the same applies to all blades Ive been working on lately. I get the best results raising a bur on both sides with my diamond stones ending in extra fine DMT then either going to a Fine white ceramic followed by a spyderco Extra fine ceramic stone. I raise a bur on both sides with each stone then alternate sides of the blade with each stroke to remove bur. I have tried all kinds of strops and compounds including green compound, diamond sprays from 1.0 down to .25 micron, on balsa, basswood, and leather including bare leather with no compound at all. I rarely see an improvement of my edge from stropping and when I do it is minimal. Far more often than not it degrades my edge coming off the extra fine ceramic. I am getting near hair whittling edges meaning if I drag the right hair across the right part of the blade and hold my tongue just right I can get it to whittle and or cut through a hair by pulling it across the blade. I just cant get to that edge where I can consistently drag a hair across the blade and it whittles consistently and eagerly. Ive also tried taking my blade to a 6000 and 16000 grit shapton combination pocket stone that Sharpening supplies was selling a while back and it only degrades my edge from what I am achieving off the extra fine spyderco ceramic whetstone. Any guesses what I may be missing that is keeping me from breaking through to my goal? I even got very close to being able to push cut a zig-zag cigarette paper last night but not real easily.