Thread: Naniwa/Ebi Kagaku "Chemical" stones...any thoughts?

In the Naniwa stone lineup, there's a category of finishing stones that includes the Junpaku 純白 or "pure white" (generally mistranslated as "snow white") 8000, which has generally been well-received in its range, and the Kagaku 化学 or "Chemical" (or perhaps "Chemistry") 4000, which nobody seems to discuss.

link to Naniwa site

The English site mentions the model numbers but doesn't give anything else. Too bad the Japanese site also provides no real information about them, but at least there are pictures.

I have one on the way but have not found any opinions really regarding it, and was wondering if anyone out there has stumbled upon it and given it a try. It looks like more of a soaker than the Junpaku, but that's probably no big deal.

I'm currently planning to shift from micropolishing film (which I still like) progression to mostly stones (Matsukusuyama 1k, Kagaku 4k, Junpaku 8k) before my Jnat setup.

Just arrived...haven't given them a workout yet.

Hope to have some impressions in a while, though I don't consider myself especially qualified to share opinions on stones.

Just make sure they are dead flat and have a go at them.
I had a "Snow white" but gave it away, somehow miss that stone!

Originally Posted by Lemur

Just make sure they are dead flat and have a go at them.
I had a "Snow white" but gave it away, somehow miss that stone!

I'll be flattening/lapping them soon but probably not tonight.

I probably could have figured out a natural stone setup, or gotten a Shapton Pro combo or something, but I guess I was attracted to these stones since they're supposedly related in Naniwa's lineup but completely different in packaging and appearance. It's a bit of a risk since I've not really read anything about the 4k and don't really trust anything I've read about the 8k, but I'm happy I've got them.

P.S. If you look at the decoration around the Kagaku box, you can see it's a stylized "Naniwa". The stone also has the same warning against soaking for a long time on the side as the Junpaku.

Finally got to try them briefly on a razor (Tosuke), but still no thorough workout.

Took out the stones and gave them a 300-grit lapping, then tried to smooth them with the 1000 grit side of my diamond plate. Sticky sticky and wouldn't let go, so I couldn't smooth them as much as I wanted. The Kagaku seemed a bit thirstier and was a bit softer and muddier than the Junpaku. Since it was just a little razor, I couldn't determine whether that'd amount to much or any noticeable dishing, but it seems like it'll happen quicker than with the 8k.

Feeling with the razor was nice and smooth. Got swarf right away and felt like I was getting a good finish. A little mud worked up (with the Junpaku it's just swarf loading up the surface, it seems) but did not dull the edge noticeably that I could tell. Arm hair popped pretty well off the 4k, and the microscope view seemed OK.

If the Junpaku is a Chosera-class stone, then perhaps the Kagaku would be a Super Stone type, just going by what I've read. It's not exactly the same kind of stone as the Junpaku but they seem to be pretty complementary. I wonder if their placement in Naniwa's lineup is accidental or if they really are meant to be treated as a series, given the differences. Still, I like it, though it's my only 4k and I have nothing to compare it to but microfinishing film.