Honing routine when using the Japanese wheel SJ-250?

[WimSpi]

I am considering purchasing the Japanese grinding wheel the SJ-250. I have two questions about that:

1) Who has examples of grinding routines when using the SJ-250. This is not about the sharpening part (which I do with the diamond stones), but about honing process. Or is honing just redundant?

2) I am using the diamond stones with the water to which the anti-rust concentrate has been added. Can I also use this mixture for the SJ-250?  Or does it have to be pure water?

Thanks in advance for the answers

Wim

[tgbto]

Hello Wim,

I tried to address this issue in this post. I know it's not a universally shared opinion but I tried to substantiate it with facts/pictures.

I found that not honing after the SJ, even after many passes at a light pressure, left a wire edge. This wire edge is very hard to detect visually, even with a (bad quality) microscope. But a BESS test confirms the impression that the knife is not all that sharp, the test medium even leaves a dent.

So I respectfully disagree with Tormek's statement that honing is superfluous.

And to be honest, I did not find that removing the burr was much faster after grinding with a SJ compared to the standard SG, I just hone as I would with the SG. The looks are awesome though.

I am not sure what you are trying to achieve with the ACC solution on the SJ. If you're "just" trying to skip the water renewal step in between Dx and SJ stone. For sure, the SJ will not rust. Reusing the solution you used with the diamond stone sounds the perfect recipe for embedding steel particles (and even a few diamonds) into the SJ stone, eventually leaving scratch marks which pretty much negates the interest of the SJ stone.

I hope this helps!

Nick.

[WimSpi]

Thanks for your response Nick,

My considerations for an SJ is to be able to make the routine shorter, but I don't read anywhere that this actually happens.
On its own, an SJ-250 is expensive (In the Netherlands $300). But a Rockhard Feltwheel also costs money. Especially if with a certain regularity diamond paste should be applied.

Surely a light form of honing is necessary.
The only 'real' benefit so far is that the cutting edge looks nice and mirror-like.

You do have a point regarding the fluid. There is always some residual metal in there. So a separate water tank for the SJ might be better.

Wim

[cbwx34]

...
My considerations for an SJ is to be able to make the routine shorter, but I don't read anywhere that this actually happens.
...
The only 'real' benefit so far is that the cutting edge looks nice and mirror-like.
...

The only way I can see it making a routine shorter, is if you could stop after honing on the SJ wheel.  It goes to what I said in the other thread that tgbto linked to, is, what if any improvement is made honing on the SJ wheel after the SG wheel, and if that is "good enough".  (I'm not saying it leaves a burr or wire free edge).

You're right about it increasing polish, (which as a side note, can that be more important for some woodworking tools?  Don't know much about that).

But I think tgbto's other points were well made... if you add the SJ wheel, you'll have more things to deal with.

[WimSpi]

Thank you.

I notice that there is no "wow" feeling in response to my question about honing with a JDS-250.
I think a mirrored cutting edge is more likely to suggest that a knife or chisel is very sharp, but I don't read anywhere that is actually always the case.

(For woodworking, a mirrored back surface is not that essential. I have been working with chisels since 1970 and have never seen mirrored back surfaces in practice.
For a chisel, however, it is important that the back surface be free of pits. Otherwise a chisel will never be sharp. The extra honing time you spend on this does lead to mirrored back surfaces. But pitting on the back of a chisel can be easily prevented, by not leaving it outside for a long time and not in humid areas).

[RickKrung]

Don't know that I can speak to your question about honing with the SJ wheel.  I will say how I use it, however.  Which is that after whatever grinding wheels (diamond series or SB/SG) I polish/pre-hone on the SJ at the same angle as grinding.  Then, I use a rock hard felt wheel with 1µ diamond paste - at some small angle higher than the grinding angle, usually 1-2º, ala KG's protocols.  That can be adequate, but usually I follow with stropping on a hanging leather strop. 

As for using the same ACC laced water bath for the SJ, I definitely do NOT do this.  The SJ imparts quite a turbid/opaque look to the water, assuming it is some of the SJ matrix being worn off.  I do NOT want that then being used subsequently with my diamond wheels and I do reuse the ACC solution multiple times.  After done with the diamond wheels, I pour the ACC solution water into a jar, through coffee filter to remove debris.  Then refill the trough with plain water for use with the SJ wheel.  Extra steps, so you may not care for it, but that is what I do. 

Rick

[WimSpi]

I really appreciate your input Rick!

Something similar was also my idea and I too am following KG on this.

And also your comment about using different water for the SJ-250. Top!
I also like the use of a coffee filter.

Wim