Natsuya journey

[Wabisabi-Ken]

Thought I would write this up as an insight for anyone interested in natsuya stones. I had recently met a Japanese friend in Kyoto with multiple jnats and was able to go and have a play with his collection, I was very impressed with his grey natsuya speckled with white dots. It felt nice, worked quickly and left a nice contrasty finish with barely visible scratching. So naturally I got on the hunt for myself..

I managed to acquire my first Natsuya which came rough cut so I went to work flattening it all out.. to my surprise it was a beautiful kind of speckled creamy white to orange gradient. I was used to seeing more creamy brown striped natsuya which to be honest I wasn't fond of in the looks department so this was a cool surprise. I was even more surprised when I used it, it seemed to work quickly generating dark swarf with minimal mud. It definitely seemed harder than my friends natsuya as I recall that self slurrying reasonably easily.. after playing around with the stone a bit I can say it seems quite versatile. With a 400 atoma nagura slurry it can create a darker kasumi with slight scratchiness, you can then work that a bit more to get a lighter contrast without visible scratches. I noticed that after working the stone you can get a burnishing effect also which gives a nice shine on the clad steel and core steel. It's definitely fun to see how the stone and blade reacts differently to different techniques!

This guy measures in at roughly 80x65x215mm and is around 435 mm3/g so it sits at 3.5/5 in the hardness range.

The stone as it arrived

And after flattening out

The results

Sorry the phone camera photos aren't great, I'm getting a macro lens soon so I can really show some detail!

I haven't actually sharpened any knives with this stone yet so I'm unable to comment on the cutting characteristics! I'll get into that later whenever I have something I need to sharpen.

 

[Wabisabi-Ken]

So after showing my stone off to fellow stone nerd he said it seems to be quite a rare colour, I definitely haven't seen any looking like that in Google photo search so I got on the hunt for more..

Incoming Jnat crack delivery!

3 more natsuya, I'm diving in!
The top one with it's darker colour and uniform finish had me interested so it's the first for clean up.

Looking interesting so far..

I present to you cheddar cheese kuro renge natsuya! I gotta say I do love me some orange and black.

About the same size as the first one it is basically the same 3.5 on hardness scale. After a quick play around this guy seems quite similar, it gives a bit more of a contrasty finish as it doesn't seem to clog up and burnish as much as the first one. It still gives a nice shine with better contrast though which I'm stoked about.

More photos to come and I'll get into cleaning up the other natsuya soon.

 

[ahhactive]

wowwww the cheese one is definitely nice. but they all are nice. seems to be finish finer than what i have seen

 

[Wabisabi-Ken]

wowwww the cheese one is definitely nice

Yeah I'm really really stoked with that one!

 

[HumbleHomeCook]

Are you flattening those by hand?

 

[Wabisabi-Ken]

Are you flattening those by hand?

My hands connected to a belt sander, yes my first one I did by hand and concrete block then atoma to finish it off. It was a long process

 

[HumbleHomeCook]

Ok that makes sense. Yeah, doing all that work on that many stones would be quite the undertaking! Gorgeous stones, thanks for sharing.

 

[ethompson]

I love these old non-striped natsuyas! I bought a bigger batch of them recently and am still working my way through flattening and testing them all. I’ve got one that super orange like yours and it’s definitely a hair more friable and easier to use but doesn’t have quite the same burnishing power as my paler one - matching your experience exactly. I’ve got one I think has some two tone going on, I’ll try and flatten that one next.

 

[Wabisabi-Ken]

I love these old non-striped natsuyas! I bought a bigger batch of them recently and am still working my way through flattening and testing them all. I’ve got one that super orange like yours and it’s definitely a hair more friable and easier to use but doesn’t have quite the same burnishing power as my paler one - matching your experience exactly. I’ve got one I think has some two tone going on, I’ll try and flatten that one next.

That's cool to hear! I just tried them on a big 330mm yanagiba but it was quite hard work to try and get an even finish with the bevel not being perfectly flat and the stones being harder to self slurry.. on the bright side after using them I can see (I think it's called alloy banding?) Some fine details in the cladding. Very cool... I went to finger stones but with the darkening of the cladding I lost the detail, another thing for me to figure out. As for the lack of mud produced I think I will try soaking them for a bit, they do seem to be reasonably thirsty so hopefully some bath time will help them to slurry easier

Phone camera can't really show it very well but I think you can see the banding a little bit.

 

[ethompson]

That's cool to hear! I just tried them on a big 330mm yanagiba but it was quite hard work to try and get an even finish with the bevel not being perfectly flat and the stones being harder to self slurry.. on the bright side after using them I can see (I think it's called alloy banding?) Some fine details in the cladding. Very cool... I went to finger stones but with the darkening of the cladding I lost the detail, another thing for me to figure out. As for the lack of mud produced I think I will try soaking them for a bit, they do seem to be reasonably thirsty so hopefully some bath time will help them to slurry easier

Phone camera can't really show it very well but I think you can see the banding a little bit.
View attachment 189660

Yeah, they’re definitely tricky to use. I’ve heard these can crack after a soak as they dry FYI, but I also have been tempted to try it multiple times. A forced diamond plate slurry and keeping the slurry wet definitely helps.

YES! The detail they can show is really awesome. I’ve frequently found banding and carbon migration with these that I didn’t know existed otherwise.

 

[Wabisabi-Ken]

Yeah, they’re definitely tricky to use. I’ve heard these can crack after a soak as they dry FYI, but I also have been tempted to try it multiple times. A forced diamond plate slurry and keeping the slurry wet definitely helps.

YES! The detail they can show is really awesome. I’ve frequently found banding and carbon migration with these that I didn’t know existed otherwise.

Hmm good to know, thanks for the heads up! I figure maybe the stripey ones could be more susceptible to cracking, so I was gonna try it on my least favourite one and seal it up well first

 

[Krxxtc._.9]

Hello!

What did u use to flatten the natsuya?