Thread: Jnat "grit" question

For the record, the stone I am currently using that gets all skippy was sold as a "Shoubu damascus asagi" rated at 5+ for both hardness and fineness

So if I use a nagura from a very fine but slightly softer Nakayama I will get a nakayama edge if I stop early, a blended edge if I allow the slurry to break down more, and the asagi edge if I keep going until the slurry is completely broken down?

Yes, but inevitably the Asagi plays a role throughout the whole honing process. I think the Asagi has to leave its footprint and the Nakayama has to break down to allow sufficient refinement. Does it get skippy even with slurry (at the end most likely)?

Damascus Asagi similar to this?

Originally Posted by Steve56

Eric is right, and I asked Alex Gilmore about slurry a couple of years ago and he also said that skurry transferred to plate glass broke down within a minute or two and became useless.

You can put it on a piece of cloth or lint free paper towel and use it to polish even delicate items like razor gold wash, fointain pen nibs and barrels, jewelry, or just about any metal. Over time my Gold Dollar test razors get shinier and don't look half bad for a Gold Dollar.

Cheers, Steve

Polished my wedding ring this way, I tried to give it kasumi finish using some suita dust. Didn't really work as I expected, but it sure fixed up minor scratches nicely!

I'm still not entirely sold on the simple "breaking down" of slurry particles. My personal theory of what is going on with the JNat process is that the slurry particles start off possibly clumped and more or less sharp edged. As honing progresses, these break apart into individual particles as well as the sharp edges begin to round and become duller. In addition, swarf from honing intermixes with the slurry. These combined I think causes the cutting to become a bit finer as the slurry is worked. The softer stones will keep cutting longer and faster than the very hard stones as they continue to pull out fresh sharp edged particles. The very hard stones will fairly quickly run out of gas in terms of steel removal and begin to polish as the particles dull and very few fresh sharp edged particles are pulled from the stone. Steel swarf helps with the polishing in the same way that a heavily loaded stone will cut finer than an unloaded stone. This factor is probably more of a burnishing. Anyway, that's my theory.

Originally Posted by Magpie

For the record, the stone I am currently using that gets all skippy was sold as a "Shoubu damascus asagi" rated at 5+ for both hardness and fineness

So if I use a nagura from a very fine but slightly softer Nakayama I will get a nakayama edge if I stop early, a blended edge if I allow the slurry to break down more, and the asagi edge if I keep going until the slurry is completely broken down?

You are simply modifying the base stone's qualities. You can't say a Shoubu edge is a Nakayama edge but to confuse further, Nakayama quarry is situated in Shoubudani mountain
FWIW both quarries were originally kept for sword polishing.

If I really wanted to spend the money I would try both stones, if the seller was agreeable & keep the preferred one.

Here is the photo from the original sale site. THe stamps are gone now, but it looks pretty much the same....




For the record, to keep it clear, THIS is the stone I have right now, and I find it skippy when used with clear water only.

I find the edge it gives to be on par with my Shapton 16k and I was hoping to find a new stone to take me up a notch