Topic: Japanese Stone and Honing Questions

[john.jcb]

I have a couple of questions. I watch this video and see a Global knife sharpened with a resulting BESS score of 75. By all standards quite a sharp edge. Should I expect an even lower value if the Japanese stone was used in lieu of the leather honing wheel? Will the ground edge just be smoother and more reflective with the Japanese wheel or actually sharper? Would a CBN 1000# be a better investment for the sharpest edge?
https://www.youtube.com/watch?v=UckPmizllk0

[wootz]

I have a couple of questions. I watch this video and see a Global knife sharpened with a resulting BESS score of 75. By all standards quite a sharp edge. Should I expect an even lower value if the Japanese stone was used in lieu of the leather honing wheel? Will the ground edge just be smoother and more reflective with the Japanese wheel or actually sharper? Would a CBN 1000# be a better investment for the sharpest edge?
https://www.youtube.com/watch?v=UckPmizllk0

The best edge apex one can get edge-leading on the Japanese SJ wheel is near 0.3 micron or 150 BESS, and it is hardly-hardly arm-shaving - it is explained in the Knife Deburring book available for free on our website, where we talk about the edge-leading sharpening http://knifegrinders.com.au/Manuals/Knife_Deburring_book.pdf - in the free evaluation version of the book it is page 15.

However, if you hone the knife on the Japanese wheel edge-trailing at a little shallower angle, we do it at 0.5 degree less using our FVB, and then deburr on the Tormek leather wheel at the exact edge angle, you can get near Gillette razor edge of 0.1 - 0.15 micron, 55-60 BESS.

The Diamond or CBN #1000 can give you true razor edge of 0.1 micron on a mainstream knife as shown in our article
http://knifegrinders.com.au/Manuals/SEM.pdf , but must be rightly deburred not rounding the apex.
However, for high-end steels you need more honing on finer diamonds to get there - as detailed in our Knife Deburring book, in the chapter about the high-end knives.

[van]

"However, if you hone the knife on the Japanese wheel edge-trailing at a little shallower angle, we do it at 0.5 degree less using our FVB, and then deburr on the Tormek leather wheel at the exact edge angle, you can get near Gillette razor edge of 0.1 - 0.15 micron, 55-60 BESS."

Hi Wootz,
I give a practical example, correct me if I'm wrong.
If I have to sharpen a blade at 15° dps, on a Tormek wheel, first I set the sharpening angle to 14.5° and then on the leather wheel I set the 15° to eliminate the burr?
Thank you

[wootz]

"However, if you hone the knife on the Japanese wheel edge-trailing at a little shallower angle, we do it at 0.5 degree less using our FVB, and then deburr on the Tormek leather wheel at the exact edge angle, you can get near Gillette razor edge of 0.1 - 0.15 micron, 55-60 BESS."

Hi Wootz,
I give a practical example, correct me if I'm wrong.
If I have to sharpen a blade at 15° dps, on a Tormek wheel, first I set the sharpening angle to 14.5° and then on the leather wheel I set the 15° to eliminate the burr?
Thank you

With a quality knife steel, yes. It is all steels listed under "negative burr", and many steels in the "in-between" group.

But not with the mainstream stainless steel knives, that we list under "positive burr", e.g. Furi, Mundial, Wüsthof, Victorinox etc - for them you must do "differential honing", i.e. after the leather wheel at 15° with the Tormek honing compound, we do extra step of removing the wire edge at 17 degrees with 1-micron diamonds.
However, if you have the Japanese SJ wheel, finishing mainstream knives on it edge-leading is all needed, we do it at a little lesser angle, in your case 14.5, to keep the apex rounding to the minimum.

[van]

Thanks Wootz, as always very exhaustive !!!