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I can add very little to what have been said above by Rich, Rick and Ken.

First-time beveling of newly made knives, of all Tormek wheels, the fastest goes on their silicon carbide SB wheel; to keep it grinding fast, keep refreshing its grains with a #80 diamond plate as soon as you see its cutting ability slowing down.
(Obviously, it is not possible to refresh the SB with the Tormek grading stone, because both are made of the same material - silicon carbide)

Tormek SJ is the best of fine Japanese wheels I tried. We only do not recommend it for honing high wear resistant blades with high Vanadium content.

10" paper wheels on an 8" buffer/grinder give you more room between the two wheels and you can hone long knives.
With smaller grinders, long knives will be bumping into the 2nd wheel, i.e. 6" grinder will limit your setup to short and medium knives.

However, you get the best sharpness, when the paper wheel diameter is close to your Tormek wheel, so for T-8 and T-7 you should go for 10" paper wheel, while for T-4 the 8" paper wheel.

Important that the buffer/grinder must be half-speed, in Europe it is 1425 RPM (not the standard 2850), and have better than average bearings, well balanced. On cheap grinders the wheels wobble and hammer the blade like crazy, as if they are out of round, even though they are not.

We've tried several PW brands, and "Razor Sharp Edgemaking System" are the best - they are denser, perfectly round and balanced, smooth, fray less and last. See the Dealers page on their website.
http://nextgen.sharpeningwheels.com/
Tell them you need only slotted paper wheels, not the kit. For knife honing, we use only slotted paper wheels.

Update: the edge-hostile plastic board has been identified as Low-density Polypropylene - often in the cutting board specs they say just "Polypropylene".

Video: https://youtu.be/_lktWJKFP2k

Could it simply be that the cutting board is continuing to remove a micro burr and it would not matter where on the board it is performed each time, that the board is helping to keep that micro board removed each pass? Just wondering.

The tiny grooves on the board seem to be important for this effect to develop in full.
The experimental data tell us that the sharpness improvement starts immediately thanks to removal of the microburr and cleaning smudge and residues from sharpening off the edge, but fully develops only after hundreds of cuts, where I believe the microburr-cleaning has played its role, while burnishing at the sides of the apex comes into play and continues, till the sharpness comes to an improved plateau after 1000 - 2000 cuts.

Thank you John and Jan.
The way we tested was 20 slicing cuts under 2 kg load in the same line on the board, move the edge to a fresh board surface, do another 20 slices and so on.

Both your explanations are exactly what must be happening - burnishing of the metal off the sides of the edge near the apex inside the tiny grooves, and smoothing off the irregularities as Jan has nicely described.
I will give myself more time to think it over and will add a paragraph to the Conclusions explaining what we see in the experiments.

[FACTORY EDGE VS RE-SHARPENED]

FACTORY EDGE VS RE-SHARPENED

I re-sharpened the knife used in our chopping board experiment at the same 16 dps, using our sharpening and deburring procedure for mainstream stainless steel knives. The edge angle was controlled with our computer software for Tormek, and verified with a laser protractor.
The only difference was that I started on #80 CBN wheel to remove the metal affected by factory sharpening, and then followed our standard procedure on CBN wheels #200, #400, #1000 and deburred as described on our website http://knifegrinders.com.au/06Procedures_SS.htm

The edge scored 80 BESS, so I had to bring it to the initial sharpness of the knives used in the experiment which was 120 BESS - I did it by rounding the apex by gently honing it on the rock-hard felt wheel with 1-micron diamonds on Tormek at 2.5 degree higher than the edge angle, till the edge started scoring the same as the knife in the experiment.

Then I tested the low-density polyethylene board the same way we did with the factory-sharpened knife.
If you ask me why i did not use the best edge-friendly high-density polypropylene board - I avoided extremes on purpose as I wanted to look further into the phenomenon of self-improved sharpness as such.



Following are the sharpness data and chart.
We see that the re-sharpened and cleanly deburred edge also gets sharper due to this mystical phenomenon, and sharper than the factory edge.
We see that it is not plastic specific, and not about the burr.
I am still scratching my head for a plausible explanation of this phenomenon.
Comments are welcome.

... In this experiment we possibly also clean/deburr and polish the edge, which results in lowering the BESS sharpness score.

Suppose it is not about the burr, suppose the apex is clean - any other explanations?

...
This was a most interesting read and I think definitely myth busting.

As I was looking at the comparison charts I thought you must had transposed the data. I am glad to see that all my boards are good for cutting. I wish a SEM was easily available to look at the differences from before and after. Did you try this using the Victorinox knives after they had been sharpened using the process outlined in your recent "Knife Deburring" book? Do knives that are at or near maximum sharpness dull following the protocol you used?

Another question is raised also; if the knife is getting sharper as shown in the tests why do they get dull cutting relatively soft things like tomatoes, potatoes and meat? I wonder if technique enters into it.

New identical knives with factory edge were used for this test on purpose, to rule out other variables and focus on the chopping board material.
Important is that the testing was done with the load within natural cutting forces.

Re-sharpened knives, provided they are cleanly deburred, outlast the factory edge, it is a commonplace.
With these data on hand, we can confidently say that if the knife fails early on an edge-friendly chopping board, it is due to incorrect technique and chiefly due to the edge rolling. 
Knives dull by 2 mechanisms: abrasion and rolling.
In my test knives are perpendicular to the chopping board and if they dull it is due to abrasion.
If the cutter often scrapes the board laterally, or holds the knife out of the vertical, the rolling will prevail.

E.g. the habit of scraping food pieces off the board with the spine of the knife rather than the edge eliminates one cause of rolling.

I have added to the end of the above PDF a page with full experimental data.

Looking at the sharpness numbers, you can see why the high-density polypropylene board comes as the best chopping board - I highlighted it in green in the table.
It was mystical to observe the knife getting sharper and sharper with every next 200 slices on it, how the edge sharpness improved twice and went on near razor sharp between 60 - 70 BESS as I kept cutting.

I am yet to digest these findings.

Our latest research on chopping boards is in the Edge Stability Testing section on our website:
http://knifegrinders.com.au/SET/Chopping_Boards.pdf

Abstract from the research conclusions:

"Of all plastic boards, the most edge-friendly is the ubiquitous high density polypropylene, while the
expensive Yoshihiro Hi-Soft board is nothing to rave about in comparison.
Acacia end-grain chopping board has no advantage over the long-grain in keeping your knife sharp;
while the end-grain bamboo board is definitely bad."
...

Hi I've been going through this book which is great but I was roundly disabused when I got to the 'high end vs mainstream knives' section.
I realised that I can't get the lasting edge on my S30V and M390 pocket knives, which is a sad thing.
I have a standard t8 set up with FVB for guided honing on the leather wheel and my new understanding is this won't polish the carbides that exist just shy of the steel edge.
So, I don't want to buy a CBN or diamond wheel right now does anyone think I could just get a 2nd leather wheel and some kind of diamond honing compound? Or would that not really make a difference. Hmm.

I've just wrote about this to a knifemaker in Canada, and can copy here how we sharpen premium wear-resistant knives. In my book I could not go that detail because of limited pages.
You can adapt our sharpening protocol to the equipment you have.
I hone high-end knives on leather wheels on Tormek, on felt wheels and paper wheels - they are not equal but all work.

If you do not have a coarse CBN/diamond wheel, bevels can be ground on the black SB wheel, but the edge must be set (apexed) on # 1000-1200 CBN or diamond wheel.
It is important to use the CBN/diamond wheel of a diameter close to the diameter of the honing paper/felt/leather wheels that you'll be using in the next steps, for the edge profile to match the honing wheels.

High volume of wear-resistant carbides, >= 3%, requires a polishing progression, as explained in my Knife Deburring book.
We do it on paper wheels with diamond paste, the sequence is 10-micron - 5-micron - 2.5-micron.
As you can see on the photo, we have 2 half-speed grinders with PW supports, but you can use a single grinder/buffer and change the wheels as you go.
Polishing on the 10-micron diamonds is done at the edge angle, 2-4 passes alternating sides, till the burr is near gone.
Polishing on the 5-mircon and 2.5-micron diamonds is done at a little less angle to spare the very apex, we set the PW supports at 0.1 degree less than the edge angle, and give the blade 2 passes each side on each wheel.



Between the wheels the blade is cleaned with a low-odour turpentine to prevent cross-contamination.

Edge-trailing honing of M390, CPM M4, Vanadis-4 & 10 and some other knife steels does not produce a wire edge, but honing the S35V, S30V, CPM-154 etc does.

We remove the wire edge on a rock-hard felt wheel with 1-mircon diamonds, on Tormek, using the FVB, at + 0.4 degree higher than the edge angle, 3 slow passes each side of the blade.

While for paper wheels the diamond paste is the best, for felt the best is a diamond spray.

Then we do the last step of finishing cleanup on a paper wheel with a mix of chromium oxide and 0.25 micron diamonds at the exact edge angle, only 1 pass each side.

This sequence gets the CPM edge sharper than disposable shaving razors, and most importantly, the edge will stay very sharp for a long time thanks to finely polished carbides, as explained in my Knife Deburring book, the chapter on high-end knives.
Every step in our sharpening protocol is of necessity, not a whim, comes from edge stability testing and SEM studies.
In other words, you can skip some steps at the cost of less sharp or less stable edge.
...

I will definitely want one of these if it makes it to production.  But I am wondering, does this have advantages over self-centring jaws, or has it been designed because no satisfactory design for self-centring jaws has emerged?

Gord

We see quite many knives produced with the edge slightly off the blade center.
This adjustable offset jig can center them better than a self-centering knife jig, hypothetically at least.
I mean, even if we had a self-centering jig for Tormek, this offset jig would still be of use for grinding some high-end knives to get symmetrical bevels of even height.
However, the right centering is not only about nice bevels, it is the key to better sharpness. For me it is an established fact that when the edge is not centered in the jig we cannot get it the same sharp as when it is centered. I've offered some explanation here >> , but no matter how you explain it, it is for fact.


By accuracy of centering we can range the knife jig solutions as follows, starting from the least accurate:
Tormek stock knife jig
Our set of knife jigs with milled offset
Some self-centering jig
Michael Peppard's adjustable offset jig
...

Video how we sharpen serrated kitchen knives, bread knives etc

https://youtu.be/T4LItIdH-FI

... personally i do not use a grooved steel on Japanese knives though.

Hi Bob,
Do I read it right that you recommend the Multicut over the regular grooved steel? I haven't tried it myself.

Your note is interesting because in our experiments we also saw that the higher HRC blades do not benefit from grooved steeling as much as from polished.

We store wheels on 12 mm s/s rods at approx 4 degrees upwards in a drilled wooden bar 70 x 70 mm