Thread: JNAT & Nagura questions/identification - help!

Hi Everyone,

Fairly new member here, some great content on this forum!

Hoping someone can give me a quick read on a JNAT and nagura that I picked up (from a mate), I'm wondering what I have and their suitability to razor honing (particularly for an iwasaki kamisori)

I'm familiar with razor honing, but not on natural stones.. some of you may be familiar with the term in golf - "$100 gear, $10 swing" - and may be thinking it's applicable here but I'd really like to learn how to use a natural stone.

One of the nagura is a very dark almost black, but in certain lights I see ruby/dark red highlights - not seen one quite like it before.

The box the stone came in just says Oohira 30 (30 I assume refers to size?) and "very hard".



Any help or advice would be very much appreciated!

Thanks!
Chris

大平礦山合砥石 --- honing stone ( awasedo ) from Oohira mine

三十型 --- size ( type 30 = 205 x 75mm )

一本選 --- type of selection


white nagura looks like chu-nagura from Mikawa ( medium grit )

black nagura seems to be Tsusima Kuronagura


I think that Oohira awasedo is not a good choice for razor finishing even when it is very hard one.

Originally Posted by Nikolay

大平礦山合砥石 --- honing stone from Oohira mine

三十型 --- size ( type 30 = 205 x 75mm )

一本選 --- type of selection

Thanks Nicolay, much appreciated! Any thoughts on the stone/nagura & razor honing? Is it a decent stone?

Originally Posted by londoner

Any thoughts on the stone/nagura & razor honing? Is it a decent stone?

I can not decide on stone quality by photo.

You should try to use it.

My green Oohiras looking like your's are not very suitable for razor honing.
So I'd prefer to use hard Nakayama Maruka Asagi and Oozuku Karasu for razors.
But I think such a stones could be suitable for prefinishing when used with slurry raised by nagura.

Fair point! I did wonder if it's more suited to knife honing but will have to give it a try - thanks again.

And one more thing to add: Sometimes working surface of stones needs to be lapped before use for razor honing to get the better result.
And it is also good to round off the edges of the stone adjacent to the working surface.
Just slightly making the radial bevels with radius of some 1mm on each edge.

Originally Posted by Nikolay

And one more thing to add: Sometimes working surface of stones needs to be lapped before use for razor honing to get the better result.
And it is also good to round off the edges of the stone adjacent to the working surface.
Just slightly making the radial bevels with radius of some 1mm on each edge.

I completely understand it's difficult to say/tell much about a stone and how it will perform just from a photo - bit of a silly question on my part. Best thing is to give it a go!

What would you suggest lapping it with? I have a truing/lapping stone but not sure whether this would work?

A worn 325 DMT would be best but second would be some sandpaper on flat glass or a tile.

Start at 220/400 and move up to 600 (or higher if you choose)

Jnats are interesting stones and kinda like woman. You never know how it's going to go until after a few dates And, If you have never used one, it may take a while to discover her sweet spot... .

I got a few Ohiras myself, all to soft for razors.

Lapping is a very good idea, both to make sure it's flat and to get a fresh surface.
Oil, dust and other things in the air gets stuck on the surface and sometimes you will find the stone is very different 1/10 of a mm down.

You could do a quick test sharpening a tool or knife on it with water only to see how hard it is.
A good stone for razors should mostly not give any slurry at all, if it does you will always get fresh cutting particles and the stone will be fast but not fine.

Best would be if you have someone close to you that could take a look at it and give it a go.
Even a stone suitable for razors can take some time to master, to learn to hone with an unknown stone is not an easy way to go since you will never know if it's your honing skills or the stone to blame.

Same with the Naguras, the best way is to compare them to known good Naguras, I agree with Nikolay, looks like a Tsusima but the other I would plainly call Shiro Nagura (Shiro - White),
it's a common name for unknown white ones.

Hopefully we're not scaring you, go ahead and start to play around with it, it's the only way to learn but maybe not on your best razor.

Edit; I do use a piece of Ohira as Nagura on some very hard jnats, makes a thick and fast slurry for fixing chips in the edge, that is fast as in naturals fast, synthetics are way faster.

Lemur, i made a few corrects. Just so it fits in more with my post above

Originally Posted by Lemur

Even a stone suitable for razors can take some time to master, to learn to hone with an unknown stone is not an easy way to go since you will never know if it's your honing skills or the stone to blame.

Even a woman suitable for dating can take some time to master, to learn to date with an unknown woman is not an easy way to go since you will never know if it's your dating skills or the woman to blame.

Originally Posted by Lemur

Hopefully we're not scaring you, go ahead and start to play around with it, it's the only way to learn but maybe not on your best razor.

Hopefully we're not scaring you, go ahead and start to play around with her, it's the only way to learn but maybe not on your best sheets.