Using the Japanese Wheel

[John_B]

I am close to purchasing a Japanese wheel for my T-8. I have a couple of question for those that have one.

Currently for most of the knives I sharpen I will use the standard wheel to sharpen the edge and then hone on the leather wheel at 2° greater angle on the leather wheel. Do you use this protocol with the Japanese wheel or do you hone at the same angle so the entire sharpened area has a mirror finish. I was thinking about honing using the Japanese wheel at the same angle then moving to the leather wheel at +2°.

[Hannsi1957]

Hi,
2 things....
first 2° more on the leather is to much. normaly 1 to 1.5 max is way enought.
second... japanese produces a burr like all grindstones, yes its mor finer like the 1000 Grit but u have one.
Japanese has no effect on sharpnes at all but..... with no other stone or CBN or Diamond u will get this mirror finish that japanese will give u.
yes use Japanese with same angle as u grind

cheers
Hanns

[RickKrung]

Based on Knife Grinders' work and their book on deburring, a gradation of angles, from lower angle honing (~0.4º) for the higher steels, higher angle honing (up to 2.4º) for lower-end steels:

"As mentioned above, the "de-rooting" angle depends on the steel:
- For high-end steels it is by 0.4 degree higher than the edge angle;
- For quality knife steels it is by 0.8- 1.6 degree higher than the edge angle;
- For mainstream steels it is by 2 degrees higher than the edge angle; and - For lower-end steels it is by 2-2.4 degrees higher than the edge angle."
(source: page 24, KNIFE DEBURRING Science behind the lasting razor edge, by Vadim Kraichuk, 2020).

There is also discussion of the use of the Japanese wheels in the sharpening/honing process. 

Rick

[bgtklbx]

I have the Japanese stone and I rarely use it. It puts a very nice polish on, but I get the same or better results on a paper wheel.

[RichColvin]

I have the Japanese wheel, but I don't use it to sharpen knives.  Rather, I use it to sharpen woodworking tools like chisels and carving tools.  It works admirably for those.


Kind regards,
Rich

[PE Pete]

I've very recently bought the SJ along with my T4 and was really pleased with the results.
Have been using in trailing edge which creates a magnificent polished finish BUT today I was using it in the trailing edge position and suddenly felt and saw a chip on one edge.
Not happy.
What you guys reckon just keep using or what??
Cheers Pete

[RickKrung]

Posting a photo really helps. 

If it is a chip on the edge/corner there probably is no problem keeping using it either way.  It is common for the SJ wheel to chip on the edge, from mishandling or during truing. There has been quite a bit of discussion on this, so do a search and some reading.  Some of us have put a radius on each edge to minimize or treat chipping.  The radius/chamfer shown in this photo does not remove all of the small chip, but is enough to prevent chipping during truing. 
 

My SJ wheel suffered major damage from a toppled folding table, severe cracks and chipping on the edge.  It became soaked in acetone in the fall and had swollen badly.  After the acetone evaporated, the SJ stone shrank and the cracks closed up.  I trued it and cleaned up the edges and still use it, even edge leading, without issues. 

Rick

[Ken S]

Pete,

Losing a chip out of your new SJ-200 wheel is definitely an "OUCH!".

One of the things I appreciate about the new Tormek online classes is that they include the developments in Tormek technique since Torgny Jansson wrote the handbook many years ago. One of these subtle advances is carefully using the stone grader to soften the sharp corners of the grinding wheel. This will lessen the possibility of chipping.

You should also email support(support@tormek.se). Include a photo of your chipped wheel and ask for advice. I have always found support very helpful and very knowledgeable.

I have watched the online classes numerous time. With each watching I learn more. I recommend you do the same. Keep a little notebook or computer file. A notation with subject, source and time into the video will speed up your learning.

Keep on sharpening and keep on posting!

Ken

[Ken S]

Rick,
Excellent (and scary) post.   

Ken