Mastering the 1000 Grit Sharpening Game

[Bret Koesser]

Let's play a game. If we assume that your favorite kitchen knife edge cannot be refined any further than a 1k grit stone, how would you get it to be it's sharpest? Okay I can hear the lawyer types already wanting to game the system by arguing over 1k stones that really aren't 1k. I get all that and also there are others that start questioning how do we determine sharpness.

I started thinking last night as my Kurosaki Gyuto was struggling with the skin of a very mushy tomato. because it's been a while since I gave it some honing/stropping love What if I tried to see how sharp I could get this SG2 blade if I stopped with the stone progression at either my SP1000 or SR1000. How sharp could I get my BESS tester results? I started off by a brief session on the SP1000 and followed it up with an unloaded leather strop. I didn't spend a lot of time on the strop, but enough I wasn't feeling much drag on the smooth side, so I tested. I got a 160 using the reloadable filament (which always seems to score a bit higher for me than the filament clips). While I wasn't completely disappointed with that result, I'm sure it can be made better. Probably much better.

When stropping, do you favor textured or smooth leather? Loaded or unloaded with abrasives? I've not used 15 micron diamond emulsions or I'm guessing there is a stropping tape equivalent. Mostly I'm looking for input on the stropping aspect to get that toothy edge with my arbitrarily chosen 1k grit limit.

 

[Nemo]

IME, the main obstacle to a sharp 1k edge (actually, any grit edge come to think of it) is incomplete deburring.

Not sure if this is an issue for you but since you didn’t mention your burr control and deburring technique, I’m just gonna put it out there, as it’s 10x more important than any stropping you might do.

 

[Dan-]

Stropping is counterproductive for cutting tomatoes.

 

[Rangen]

Cutting a mushy tomato benefits from some tooth. So does longevity of an edge in the kitchen. I often don't go beyond 1K, for those reasons. I am, in part, trying to avoid too much refinement. That also means I try to avoid the need for stropping, preferring successive passes on the 1K at increasingly light pressures.

I do not own a BESS tester, and probably never will, because I strongly suspect that chasing the best results on one would not give be the best usable and long-lasting kitchen edge.

However, my technical answer to your question is that I would finish with many leading-edge passes on the Shapton Glass 1K at very very light pressures. The stone is so firm, so reluctant to yield a slurry, that you can eventually get an edge much finer than a 1K edge that way. That's what I did when I set myself the task of shaving off of a 1K edge.

 

[Bret Koesser]

Stropping is counterproductive for cutting tomatoes.

I didn't think that a leather strop removes any metal or even polishes without any compound. So how is that counterproductive? Stropping is purely about burr removal and edge straightening. If you add abrasives to the strop, then it polishes the scratch pattern. Or is that incorrect?

 

[HumbleHomeCook]

You're kind of chasing opposing measurements of success. The BESS doesn't care about anything more than the fineness of the apex. Cutting tomato skins biases to a "toothier" edge and that isn't going to get captured by BESS.

Non-stone stropping will always be controversial. Suede side stropping is more about burr removal while smooth side is more about polishing. That holds whether you're using an abrasive or not. These are generalizations.

My general suggestion is to focus your efforts on improving your stone results.

 

[ch_br]

I periodically push myself into this exercise to test and improve my skills.

THE EXERCISE:

Use a single grit stone to sharpen and NO OTHER equipment. No strops.

IMO its the best way to test knowledge and practical skills.

Ive done this all of the following grits:
400 grit
800 grit
1000 grit
3000 grit

IMO this exercise truly tests your all around abilities of:

• diagnosis (blade examination)
• Hands on sharoening skills
• blade manipulation
• stone manipulation
• water management
• Slury management
• Swarf management
• Burr management
• Removing ALL micro chips
• Constant evaluation
• on the fly adjustments
• Speed
• and more.

Always makes me happy when I gain a new insight doing so.

What I've found is the more you know about obtaining you results on the stone, particularly the initial in the progression, the greater (and higher quality) the results -- EVERY TIME.

Try it, but be warned it will test your patience and mental fortitude also.

 

[mengwong]

Experimental design TODO – I want to put a tomato on top of the BESS cylinder and try a DE razor vs toothy SG1k vs serrated steak knife

 

[Redwax]

Stropping is counterproductive for cutting tomatoes.

That's a bit simplistic. It can be but isn't necessarily true.

As to the question, I think it's the same approach as any other edge. You want to gradually reduce pressure on the finishing stone and progress to deburring.

Personally I usually finish by using a strop to make sure the burr is as gone as possible which I judge by feel, sight and sound but a lot of people have an aversion to strops and finish on the stone. Stropping can be a couple of strokes to tens of strokes depending on several factors like steel type, hardness, carbide type, carbide volume etc. as well as desired finish. So stropping can be anything from verifying that deburring is already complete to getting rid of some remaining burr off the stone and even refinement.

As always try stuff and see what works for you.

 

[Benuser]

Please note that the SP1k is on the coarse side — about JIS 700. Great if you're achieving a complete deburring at that grit with a SG-2.
I wouldn't be surprised if all that stropping led to a nice, even wire edge. Avoid any board contact.

 

[cotedupy]

To echo what a lot of people have said above - concentrating more on your end game deburring is going to produce better results initially than trying to ameliorate it with stropping.

I find that if your deburring is very good then newspaper or cardboard will leave more bite and aggression on an edge vs leather stropping which polishes edges more but is better for tidying up small inconsistencies in your deburring.

Something to note when thinking about this is what HHC says here:

You're kind of chasing opposing measurements of success. The BESS doesn't care about anything more than the fineness of the apex. Cutting tomato skins biases to a "toothier" edge and that isn't going to get captured by BESS.

This is because ‘sharpness’ is a product both of the edge itself and what your trying to cut. A bladed instrument can be sharp when cutting one thing but not sharp when cutting another.

When I’m teaching sharpening I often make a distinction between ‘sharp’ and ‘keen’. And by my definitions of the two: BESS would test for keeness.

Experimental design TODO – I want to put a tomato on top of the BESS cylinder and try a DE razor vs toothy SG1k vs serrated steak knife

I don’t know how serious Mengwong was being here, but it’s a fun thought experiment nevertheless.

A razor would win this hands down, because it has a minute edge angle compared to knives and that would easily outweigh the advantages of having micro or macro serrations on a knife.

Why don’t we all cut tomatoes with razors then? Obviously it’s because of fragility. A razor edge would crumble the first time it hit a board, that kind of edge on a kitchen knife would be called a ‘burr’ or ‘wire edge’. Again the definitions of those two terms depend on what you’re doing with your blade.

Razors are interesting example too in regards what I was saying above about ‘sharpness’. Because the way you hone a razor - to a very high grit and stropped extensively - is designed to make it very sharp when cutting one thing: your hair. But not very sharp when cutting another: your skin. A razor finished at a low grit would cut your face to ribbons.

 

[Bret Koesser]

Lots of good information going on here. @HumbleHomeCook makes a good point that my premise that I could use a BESS tester to somewhat judge my result is misplaced. So my question is how does one evaluate the completeness of burr removal? I know there's the thumbnail test, three finger test, etc. I guess I was hoping for a more objective way by using a tester, but I totally get what is being said about sharpness being a multi-factor thing and keenness or apex width may not be the proper thing to measure. I guess maybe a jeweler's loupe or microscope to visually inspect the quality of the apex is the measurement? I keep intending to get a better way to visually inspect my edges.

I mean, it's not like I'm a sharpening rookie or inept at it, but I'm not so arrogant to think there isn't plenty of room for me to grow and become more knowledgeable. I did several leading edge passes on my SP1k with decreasing pressure, to the point I was using less than the weight of the blade and it seemed like there was no burr and the apex seems to even out. I'm just looking for another way of confirming my observations.

 

[cotedupy]

Lots of good information going on here. @HumbleHomeCook makes a good point that my premise that I could use a BESS tester to somewhat judge my result is misplaced. So my question is how does one evaluate the completeness of burr removal? I know there's the thumbnail test, three finger test, etc. I guess I was hoping for a more objective way by using a tester, but I totally get what is being said about sharpness being a multi-factor thing and keenness or apex width may not be the proper thing to measure. I guess maybe a jeweler's loupe or microscope to visually inspect the quality of the apex is the measurement? I keep intending to get a better way to visually inspect my edges.

I mean, it's not like I'm a sharpening rookie or inept at it, but I'm not so arrogant to think there isn't plenty of room for me to grow and become more knowledgeable. I did several leading edge passes on my SP1k with decreasing pressure, to the point I was using less than the weight of the blade and it seemed like there was no burr and the apex seems to even out. I'm just looking for another way of confirming my observations.

A very valid follow up q…

Certainly looking at an edge under a scope, or even a loupe could help with this.

Paper tests, both the feedback and the sound, are good too.

However it’s worth emphasising just how accurate the thumbnail and finger tests can be when you’re properly dialled into them with a bit of practice. And personally that’s all I use. You’ve got billions of years of evolution on your side, and it’s made the ends of your hands extraordinarily sensitive.

 

[HumbleHomeCook]

Another thing to keep in mind is that residual burr will typically not last long. It'll roll, crush, or rip fairly readily as it is a weakened structure. So if you experience brilliant sharpness for a cut or two and then notice the edge (or spots) change, it is likely there was residual burr.

De-burring is the never-ending pursuit in sharpening. It's understanding that that begins to really refine your sharpening and focus.

 

[Bret Koesser]

@cotedupy maybe, but these old-ish fingers don't seem quite as sensitive as they used to be.


@HumbleHomeCook I understand what you're saying. For me, I feel that I had an "a-ha" moment years ago about the residual burr. I had a pocket knife that I was giving particular focus on getting very sharp. I don't recall what stone/strop/honing device I was working on, but with each pass I would feel the edge shift to the side opposite the edge that was on the stone. Obviously that was the point where I was just moving the burr around and then for whatever reason (unknown at least at that time) the edge suddenly didn't feel as sharp and I thought that I screwed something up. However paper test results and hair shaving ability were even more amazing...and the edge lasted longer. Now, all this is nothing new and is the stuff which you all are trying to convey to me I believe. So I think I understand and continue to see that burrless edge. I'm just a tinkerer (like all of us I suspect) and am looking for better ways to do this. The other factor in this journey is that I'm spending more time freehand sharpening with ceramic & diamond stones. That changes the calculus a bit...I mean an apex is an apex, but burr removal feels a bit different.

I still think that a leather strop is a viable tool to make that happen, but I want to explore the "stone only" burr removal and then compare, perhaps visually, with strops using no compound and then maybe an abrasive emulsion that matches the coarseness of the stone like perhaps a 15 micron diamond compound. Theoretically that should yield similar results.

"In theory there is no difference between theory and practice. In practice there is." - Yogi Berra

 

[Dan-]

This will help you get better.

https://www.kitchenknifeforums.com/threads/kippington-deburring-video.44003/

 

[Benuser]

I still think that a leather strop is a viable tool to make that happen, but I want to explore the "stone only" burr removal and then compare, perhaps visually, with strops using no compound and then maybe an abrasive emulsion that matches the coarseness of the stone like perhaps a 15 micron diamond compound. Theoretically that should yield similar results.

Are you sure? On a stone you apply edge leading strokes, or longitudinal ones. On a strop only edge trailing. This has consequences when you're willing to abrade a burr.

 

[Desert Rat]

You're kind of chasing opposing measurements of success. The BESS doesn't care about anything more than the fineness of the apex. Cutting tomato skins biases to a "toothier" edge and that isn't going to get captured by BESS.

Non-stone stropping will always be controversial. Suede side stropping is more about burr removal while smooth side is more about polishing. That holds whether you're using an abrasive or not. These are generalizations.

My general suggestion is to focus your efforts on improving your stone results.

The Bess is measuring the force it takes to cut through the thickness of the wire.

But is that actually the most refined apex or the most acute edge angle?

 

[HumbleHomeCook]

The Bess is measuring the force it takes to cut through the thickness of the wire.

But is that actually the most refined apex or the most acute edge angle?

Yeah, good point and fair enough. Either way it's still not accounting for any slicing tooth.

 

[cotedupy]

The Bess is measuring the force it takes to cut through the thickness of the wire.

But is that actually the most refined apex or the most acute edge angle?

Yeah, good point and fair enough. Either way it's still not accounting for any slicing tooth.

It’s an interesting q. Though what I think is the probable answer will seem very obvious when I say it…

A combination of the two. Though at lower grit finishes the edge angle will have proportionately more impact on the BESS score. At higher grit finishes less so.

 

[Desert Rat]

Let's play a game. If we assume that your favorite kitchen knife edge cannot be refined any further than a 1k grit stone, how would you get it to be it's sharpest? Okay I can hear the lawyer types already wanting to game the system by arguing over 1k stones that really aren't 1k. I get all that and also there are others that start questioning how do we determine sharpness.

I started thinking last night as my Kurosaki Gyuto was struggling with the skin of a very mushy tomato. because it's been a while since I gave it some honing/stropping love What if I tried to see how sharp I could get this SG2 blade if I stopped with the stone progression at either my SP1000 or SR1000. How sharp could I get my BESS tester results? I started off by a brief session on the SP1000 and followed it up with an unloaded leather strop. I didn't spend a lot of time on the strop, but enough I wasn't feeling much drag on the smooth side, so I tested. I got a 160 using the reloadable filament (which always seems to score a bit higher for me than the filament clips). While I wasn't completely disappointed with that result, I'm sure it can be made better. Probably much better.

When stropping, do you favor textured or smooth leather? Loaded or unloaded with abrasives? I've not used 15 micron diamond emulsions or I'm guessing there is a stropping tape equivalent. Mostly I'm looking for input on the stropping aspect to get that toothy edge with my arbitrarily chosen 1k grit limit.

There are so many ways to deal with burs and different stropping options that I think it will just come down to what you are looking for in your edge.
The cleaner the edge off the stone the less aggressive the strop needs to be, but as far as I know all stropping will remove some tooth from the edge.

I don't use a leather strop on my knives simple because it's more convenient for me to grab some newsprint or even strop on my butcher block.

 

[Benuser]

If you're seriously considering applying a 15 micron diamond solution on a strop, why not try how deburring will work by edge trailing on your stone?
Edge trailing is very effective in abrading a burr. A bit too effective, I'd say. Never achieved any edge trailing without raising a new, fresh burr on the other side.
Edge trailing only is a never ending story. A single edge trailing pass on a stone can be useful, but the necessary edge leading to abrade the new burr isn't possible on a strop.

 

[Bret Koesser]

If you're seriously considering applying a 15 micron diamond solution on a strop, why not try how deburring will work by edge trailing on your stone?
Edge trailing is very effective in abrading a burr. A bit too effective, I'd say. Never achieved any edge trailing without raising a new, fresh burr on the other side.
Edge trailing only is a never ending story. A single edge trailing pass on a stone can be useful, but the necessary edge leading to abrade the new burr isn't possible on a strop.

It was mostly just thinking and wondering how deburring is different from stone to strop. I think I stated prior to that, deburring on the stone with edge leading strokes. It's all to obvious that everyone has a technique and/or a theory. The purest way to prove it out is to try it with some way to evaluate the results...again that goes back to my earlier comments of questions about using a bess tester or if it would just have to be visual inspections to determine how cleanly the burr has been removed from the apex

 

[mengwong]

Buy it

you know you wants it

 

[Benuser]

So far, I've found the finest cigarette paper a great tester. And for a remaining burr: medication sachets will immediately push any burr to one side where it becomes apparent.

 

[Kawa]

You can 'use' bess score to check the results of the same knife finished on the same stone. A clean apex gives a lower score then an apex which has a flubby piece of metal hanging towards one side. You measure pressure needed to cut the wire. Ofcourse, keen and thin are key for a low score, but, isnt that what sharp means?

Sharp by this definition just doesn't mean good performance in kitchen use per se.

Thin paper is nice aswell, but to feel the difference on paper between 80 and 140 bess score is very minimal.

 

[Benuser]

Two questions, if you don't mind.
The thin paper you're speaking about, do you mean thin cigarette paper? It's my prefered test. Of course, if ragged it's quite obvious. But the noice tells a lot as well.
With some steels and poor sharpening a wire edge all along the blade isn't uncommon. Crazy sharp until the first board contact. Wondering whether it passes the test.

 

[Kawa]

Im Dutch, so yes, I do have ricepaper for joints (I think thats what you mean by thin cigarette paper, the stuff that won't keep burning when smoking) from the brand Smoking (rizla blue feels thicker).

I have a bad hearing (genetics), i'm missing around 60 db in both ears. Noice feedback isnt my strongest point (although I stil use this feedback during sharpening). I'm not near deaf, just have hearing aids. But when at home, I like to put them off.

To be honest, I've never done a bess test right after stone/strop and again after the first meal. Same with cigarette paper.
I do keep track of my bess scores with some knives (ey, sharpening is 100% hobby for me, not something that is needed for my profession) to somewhat reflect on the results after months/years.

When the knife dulls very quick, I know I did a poor job. Dull after 1 or 2 board contacts, that hasnt happened to me in a long time.

Will try the paper test before and after first meal after the next sharpening! Interessing

 

[Benuser]

Looking forward to hearing from you!

 

[Taurahe]

I didn't think that a leather strop removes any metal or even polishes without any compound. So how is that counterproductive? Stropping is purely about burr removal and edge straightening. If you add abrasives to the strop, then it polishes the scratch pattern. Or is that incorrect?

this is incorrect. Even without compound, you are polishing the metal. Stropping is counter productive because it removes the micro serrations from the edge.... AKA toothiness. Compound speeds up the process. ........... Having worked in professional kitchens off and on for 20yrs, I will share a secret to slicing tomatoes quickly and easily........ use a bread knife. Thats it. I know, you spent $500 on a fancy Japanese knife , it should burn through tomatoes....... blah blah blah. Thick skinned veg like tomatoes and peppers are ruthless on a knifes edge. A bread knife is the bees knees, every single time. Spyderco makes a $22 short serrated knife in BDN1 that is perfect for tomato prep... but any bread knife will do.

If you insist on slicing tomatoes with a plain edge knife then as you know it needs to be sharp AF...... practice deburring on the stone itself. Its all about proper technique, in both sharpening and deburring. I am admittedly not good at it but I am getting better