Nagura Stones

N

neeman

Joined
Apr 5, 2007
Messages
6,249
Hi,

I would like to mine your expertize

Nagura Stones
  • What do they do
  • How do they work
  • When to use them

thanks

Neeman
 
Blues,

Thanks
The artical is aimed at natural stones
I am using Chosera stones
 
I use my nagura to flatten my stones and create slurry.
I use them before and after each use of the stone.

Also I have different grit nagura for different grit stones.
 
As I understand it there are two types of Nagura stone. One would be a stone with different characteristics from the polishing stone and is used mostly to flatten the stone to a small measure after each use and to free the stone from embedded swarf.

As matched Nagura (is the same grit as the polishing stone) and can be used to make a slurry and also for spot flattening and to free embedded swarf.

From my limited experience with man made waterstones, the mud can have several effects. Generally it is thought to speed grinding action when allowed to build up, then rinse and finish on a clean stone for maximum refinement - it is renowned for this action on the Belgian coticule. It introduces a bit of a lapping action to the mix that makes for a very gentle removal of steel and some interesting surface characteristics.

In my experience, it can work the opposite and create a slower grind and finer polish, a trait I believe is applicable to how hard or soft the underlying stone is. On harder stones it seems to act with more aggression, and on softer stones it seems to slow the grinding down and act more gently.

I took a diamond grit sawsall blade and cut 1/4" slices from all my waterstone ends so I could have matched nagura stones.

Hopefully some of the folks with a lot more breadth of knowledge on this subject will chime in.

Martin
 
Thanks

I have three Chosera stones and the same Nagura stone came with all of them
So they are not matched
I use them to clean the stone after use

So to refine my question
I do not know if and when to use the Nagura stone for making a slurry for sharpening and on which stone
 
Nagura stones are a complicated subject. The referenced article is a good start. Yes it refers to Natural stones and not synthetic stones. Synthetic stones are mostly cleaning stones and NOT nagura stones. You might loosely call a matched stone - even a synthetic stone a tomonagura (tomo means same), but even here it more properly refers to natural stones. I am a 'fan' of using natural stone tomonaguras.

Specifically the Chocera stones are accompanied by a 600 grit stone. This is NOT a nagura stone, but a cleaning stone and not a particularly good one either. The Chocera 600 stone is a better stone than the 600 cleaning stone. The idea of using the same 600 grit stone on stones from 400 grit to 10k isn't a very good idea. Even at 600 grit, why use 2 different stones?

The idea that a nagura stone is rubbed against another stone is largely an artifact of history. Originally nagura stones were full sized stones incorporated into a sequence of stones used for sword polishing. This included Chu naguras, boton naguras, koma naguras etc. It is only more recently that this use of true natural naguras became commonplace when used in conjunction with Japanese natural polishing stones.

You also don't incorporate the mud from these cleaning stones into the slurry used for sharpening.

This is just the tip of the subject, but I did want to clear up a few points of confusion.

---
Ken
 
Ken,

excellent

this is the answer I have been waiting for
technical and practical
now I understand

thank you
 
As an importer of both Japanese synthetic and natural stones, I often recommend tomonaguras and other naguras. If you ever want to have a much more detailed conversation about naguras, feel free to contact me anytime.

Here's an uncommon and relatively rare nagura, a Jokeji. It is a stone that is 'smoked' only at specific times of the year. The smoking process brings out it's qualities. It is used as a somewhat coarser nagura and precedes a chu nagura. Like I said it can get to be a complex toipic.


1520600_654462564604144_1882000071_n.jpg



---
Ken
 
Here's another nagura, a Botan nagura. It is cut in the shape of a slab rather than the little chunks one usually sees. It is mounted on an EdgePro blank for support. While it can be used on an EdgePro it can also be used on a polishing stone as a nagura or even used by sword polishers as well. Yes it is a small stone for sword polishers, but given it's rarity it does get used that way by some of my sword polishing customers.


1978561_709887299061670_685661262_o.jpg


---
Ken
 
So if we use a smaller piece of the same stone, this is referred to as a tomonagura. Since there are a wide variety of natural stones, here is a selection of tomonaguras along with some naguras like the Jokeji mentioned earlier. To the very knowledgeable stone users like the person receiving this selection of tomonaguras, this represents a palette of great complexity and nuance to perform some quite sophisticated sharpening and honing procedures as well as polishing with a very subtle level of sophistication.

10007354_704020892981644_1039089866_o.jpg


---
Ken
 
ksskss said:
So if we use a smaller piece of the same stone, this is referred to as a tomonagura. Since there are a wide variety of natural stones, here is a selection of tomonaguras along with some naguras like the Jokeji mentioned earlier. To the very knowledgeable stone users like the person receiving this selection of tomonaguras, this represents a palette of great complexity and nuance to perform some quite sophisticated sharpening and honing procedures as well as polishing with a very subtle level of sophistication.



---
Ken
Click to expand...

Hello Ken (schwartz?)
My name is Eytan, and i'm using natural water-stones and offer sharpening services in Israel,

The subject is very complicated and I'm teaching myself.
Hare in Israel we don't have much information on the subject and I get the most information from articles, videos, etc..
do you know where can I find reliable information on the subject?

Also, I became interested in Katana polishing , and I'm looking for Chu Nagura- big one.

Thanks

Eytan Keydar
 
Hi Eytan,

Just contact me and I can get this for you. I'm Ken Schwartz. I do have some coming in (2 different types of Chu Nagura) but you may want something bigger.

---
Ken
 
10514270_779033625480370_455073097529917129_o.jpg


Several sizes of Tsushima Nagura. These come from an undersea mine from an island off the coast of Japan which has been closed since the 1980's. Useful as a nagura in the same range as a chu nagura. It can be used in several ways including as a full sized stone. Because of its hardness, it is well liked for use on plane blades as well.

---
Ken
 
ksskss said:
Hi Eytan,

Just contact me and I can get this for you. I'm Ken Schwartz. I do have some coming in (2 different types of Chu Nagura) but you may want something bigger.

---
Ken
Click to expand...

Hello Ken

we are friends on FB so i'll send you PM

Thank you.

Eytan
 
You must log in or register to reply here.
Back
Top