Too sharp for food?

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v4257

v4257

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I have a rookie question - which you experienced folks can probably solve quick.

I have some experience sharpening but my old setup was King 1K, strop compound, leather and done. I recently upgraded to better quality J-Kives (Anryu, Takamura) and got a 6K to up my sharpening game.

I am finding that after 6K - the edges are super sharp & smooth for paper tricks and even shaving hair BUT they do not grab tomato & pepper skins eagerly. They skip over a bit. Is the edge too polished?

How do I get the best balance between toothy and sharp?
 
+1 finish on 3-4K

alternatively, use less time and pressure on 6k to keep more 1k bite
don't try to form a burr or convex or microbevel on pure carbons at 6K
maybe borrow another brand or 3-4k and test technique
 
HRC_64 said:
+1 finish on 3-4K

alternatively, use less time and pressure on 6k to keep more 1k bite
don't try to form a burr or convex or microbevel on pure carbons at 6K
maybe borrow another brand or 3-4k and test technique
Click to expand...

Thank you for the feedback!

Yes - I do suspect 6K is the issue. When I was a 1K only guy - the paper tricks were less slick - but the edges were grabby and I didn't have any trouble with tomato skins etc. I'm going to do fewer passes on the 6K next time. Thanks!

Btw - is there any truth to the 'natural stones give you grabby edges'. I'm starting to look at Ark stones - but I'm wondering it's more nostalgia & charm rather than effective sharpening when compared to modern synth stones?
 
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When people say that they're talking about jnats. Arks are a whole nother thing. They leave more wood working edges. Instead of cutting they mostly burnish steel and leave a very smooth edge. With jnats I have no experience
 
v4257 said:
Thank you for the feedback!

Yes - I do suspect 6K is the issue. When I was a 1K only guy - the paper tricks were less slick - but the edges were grabby and I didn't have any trouble with tomato skins etc. I'm going to do fewer passes on the 6K next time. Thanks!

Btw - is there any truth to the 'natural stones give you grabby edges'. I'm starting to look at Ark stones - but I'm wondering it's more nostalgia & charm rather than effective sharpening when compared to modern synth stones?
Click to expand...
Jnats will give you more teeth and bite at equivalent higher grit levels. As you use them the particles break down and become finer while some remain coarse so as you sharpen the edges become kinda "serrated" but super sharp too. Synthetic stone particles don't break down so they will never sharpen like that, they just smooth out the edges.
IMO, just get an aizu or aoto and be done with finishing, they can be had within the 3k-5k grit range depending on the stone you get, but once you got the finishing down, they're just amazing.
The other way to overcome sliding over waxy foods is to simply take the sharpness to insane levels but are you willing to spend that money on stones and do you have the skills to do it too? And do you have knives that will hold that edge long enough such that it won't become dull after a single meal prep or even within that single meal prep?
 
That experiment was done on an asagi which are hard stones in general and are difficult to break down. If the experiment was performed on a softer stone, the results could be different. Regardless, fact still remains, the longer you work on a jnat the finer the edge, whether the particles break down or not. Theres a reason why sword polishers take days and work non-stop on sharpening on jnats.
 
vicv said:
https://scienceofsharp.wordpress.com/2014/05/28/does-j-nat-slurry-break-down/
Click to expand...

The relevant bit is in the comments

I don’t believe there is any controversy as to whether the slurry changes consistency with use, becoming “less abrasive.” This is an accepted observation.
However, the only change we observe in the slurry is that the phyllosilicate component decomposes into thin sheets.
The silicate particles may be slightly abrasive, but the combined effect is expected to be dominated by the abrasiveness of the silica particles.
So, yes the phyllosilicate particles almost certainly play a role, but the physical mechanism has not been established.
Click to expand...

The slurry breaks down in terms of the effectivness of the grit. This breakdown of what is essentially something like clay has the effect of a finer finish. So you have an everage decrease in micron size of the slurry, but technically the "abrasive" component as a standalone is not getting smaller.

So this is all sort of a word game ... the slurry breaks down in average size, and the effectiveness of the slurry breaks down in effective size, but certain sub-componennts (importantnly, the strongest abrasive components) don't break down as readily if at all.

at least I think thats right.
 
v4257 said:
6K - the edges...not grab tomato & pepper skins...skip over a bit...edge too polished?
Click to expand...

Try stropping the knives on newsprint? The newspaper is likely higher than 6k grits anyways but it might help, or even diamond strop, et cetera, if you wanted to.
 
v4257 said:
Thanks! So in all cases stop at 3K? Does going higher cause this skin-skipping/lack of grab I'm experiencing?
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It helps. Not spending as much time on the 6k will also. I've been experimenting with a 500->6k (about 5-10 passes per side at light pressure) progression. I'm liking it so far but I've only used it for 1 shift.
 
Try only doing a few trailing strokes on the 6k. By few I mean like 5-6 not more. The edge off the 1k as to be burr free and clean.
 
For tomato and pepper skins you need either "toothy" 1k-ish edges OR super high polished 12k edges or something similar to a straight razor edge. In between the tough skin over softer material deflects and the knife slides. The 1k edge acts as a saw, to actually easily cut the skin requires a VERY sharp edge, and that edge will probably fail very quickly in use.

Go easy on the 6k stone and strop on newsprint (1 micron carbon particle in the ink) or chromium oxide on a hard substrate, but lightly. You want a very slightly serrated edge with the "points" very very polished and sharp, you don't want a straight razor edge.
 
Thanks all! This is a lot of potential experiments I can try!

To confirm I was doing 1K->6K->Strop on Crox on Canvas 10x->Strop on Leather 10x. I'm going to try both skipping the 6K and spending less time on the 6K. I will report back after the next experiment.

I can report that in the time since the last 6K sharpening, the knives seem to have gotten better at the 'grabby/toothy' aspect. I suspect that the normal wear and tear and created a more jagged/toothy edge at the microscopic level (still looks super shiny to the eye).

Thanks also for the notes on natural stones. I'm fascinated and will keep an eye out for a moderately priced JNAT. :)
 
Also try only 2 or 3 stropping motions on one strop. That's it. More rounds the edge
 
I'd stick a WTB 'First JNAT' post up on BST with your budget and someone knowledgeable will more than likely come along and sell you something nice.
 
I too finalize with a 6k then a few licks on a diamond strop followed by a single pass on flesh side leather. All strokes are very light and I still have the toothy edge for tomatoes and peppers.
For me, learning to use the low pressure strokes moved my sharpening up to the next level, just another suggestion for you to consider.
 
psfred said:
For tomato and pepper skins you need either "toothy" 1k-ish edges OR super high polished 12k edges or something similar to a straight razor edge. In between the tough skin over softer material deflects and the knife slides. The 1k edge acts as a saw, to actually easily cut the skin requires a VERY sharp edge, and that edge will probably fail very quickly in use.

Go easy on the 6k stone and strop on newsprint (1 micron carbon particle in the ink) or chromium oxide on a hard substrate, but lightly. You want a very slightly serrated edge with the "points" very very polished and sharp, you don't want a straight razor edge.
Click to expand...

I find that up to 4-6k all my knives cut tomatos and peppers like they weren't even there. At about 6-8k they start hesitating a little depending on what steel.
 
I can only share my own experience:

A few times I’ve thought I was using the wrong tool, either making it too sharp/smooth/refined, or the tool (stone/strop) was somehow undoing some of my earlier work. It was my technique every time. I also bought the same knife in three steels and decided upon one, but now I’m thinking that also was my sharpening technique and might actually rebuy one. I like a natural stone finished edge (either 7k->Jnats or 2k->Aoto and/or Aizu -> finishers) and I use diamond loaded leather for post-shift touchups. If I’m having problems with tomato or pepper skins, I fool with the knife until I don’t. Or a Suehiro Rika 5k is a great balance of smooth and toothy for kitchens.
 
I swear that, after finishing on a 5000 stone, my knives cut tomatoes better before I strop them than they do after, even though a paper cut test clearly shows them to be "sharper" after stropping—cleaner edge on the cut, less noise, and less effort.

I'm honestly beginning to wonder whether stropping is not such a good idea for kitchen knives. I'll experiment some more next time, going ultra-light on the stropping with only a few strokes.

I'm getting doubts about the usefulness of the paper cut test, too. I don't need to cut paper with my kitchen knives because I rarely feel like eating paper…
 
better is to test your edge on a citrus rind and see what it takes to efforless zest with it...in continuous strips no pith
this requires good bite and good shape and a touch of quality in the blade profile
 
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HRC_64 said:
better is to test your edge on a citrus rind and see what it takes to efforless zest with it...in continuous strips no pith
this requires good bite and good shape and a touch of quality in the blade profile
Click to expand...

Gotta try this as well, looks like key lime pie is on the menu for the foreseeable...
 
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