Chosera 10k stone and its Nagura stone possible problem, advice needed

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daberti

Joined
Apr 2, 2005
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Yesterday I used my Chosera 10k to give it the final finishing to my own Benchmade 810 Contego, after Chosera 400, 600, 1000, 3k and 5k.
I built the slurry on 3k and 5k effortlessly with their Nagura stones.
Normally I used the Red DMT 6 Inch Diamond Whetston Bench Stone to build the slurry on 10k, but Yesterday, after the usual "soaking" in water until no more bubbles were released, I made up my mind to use its own Nagura stone (soaked as well).

The problem it was that the slurry came up, but it was made of either 10k particles and Nagura brownish particles. Obviously enough I washed away the whole stuff and decided to postpone the finishing process.

Is this "mixed" slurry expected? Should I revert back to DMT slurry making process or did I simply miss something?

Thanks in advance for any help
 
daberti said:
Yesterday I used my Chosera 10k to give it the final finishing to my own Benchmade 810 Contego, after Chosera 400, 600, 1000, 3k and 5k.
I built the slurry on 3k and 5k effortlessly with their Nagura stones.
Normally I used the Red DMT 6 Inch Diamond Whetston Bench Stone to build the slurry on 10k, but Yesterday, after the usual "soaking" in water until no more bubbles were released, I made up my mind to use its own Nagura stone (soaked as well).

The problem it was that the slurry came up, but it was made of either 10k particles and Nagura brownish particles. Obviously enough I washed away the whole stuff and decided to postpone the finishing process.

Is this "mixed" slurry expected? Should I revert back to DMT slurry making process or did I simply miss something?

Thanks in advance for any help
Click to expand...

Straight off, I'm not familiar with the 10k Chosera, but after having a couple of issues using alternative methods of mud generation, I finally took a diamond sawsall blade and cut a 1/4" off the end of all my waterstones. A 100% match to the stone, binder and all, and it also works great to unclog and spot-flatten the stone.
 
It is expected , but that "nagura" stone is 400 grit. I assume you probably don't want 400 grit scratches on your 10k finish...

The method martin describes creates a stone called a "TomoNagura" which means "same stone" in Japanese. This is the preferred method with Japanese Naturals , although it is not really necessary on a synthetic stone. If you would like to raise a slight mud use a well broken in DMT or Atoma plate (as fine as you have).

With Natural stones you can mix and match nagura. Say by using some Iyoto Nagura on my Meara stone I can create a slightly coarser faster Meara finish. Or by using Nakayama Iromono Nagura on the same Meara I can make it slightly finer.
 
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Sadden said:
It is expected , but that nagura stone is 400 grit. I assume you probably don't want 400 grit scratches on your 10k finish...

The method martin describes creates a stone called a "TomoNagura" which means "same stone" in Japanese. This is the preferred method with Japanese Naturals , although it is not really necessary on a synthetic stone. If you would like to raise a slight mud use a well broken in DMT or Atoma plate (as fine as you have).

With Natural stones you can mix and match nagura. Say by using some Iyoto Nagura on my Meara stone I can create a slightly coarser faster Meara finish. Or by using Nakayama Iromono Nagura on the same Meara I can make it slightly finer.
Click to expand...

Thanks Sadden.
The finest diamond stone I own is a well broken in 4" Green DMT .
One thing that makes me think...Chosera 10K it is not properly cheap, I'd have expected a suitable Nagura stone :(
Having a slurry with a mix of 400/10000 grits ain't my favourite ticket !!
On the other hand the 10000k without slurry clogs quite a bit IMHO
 
The red "nagura" with the Chosera stones IS NOT A NAGURA STONE! It's a cleaning and leveling stone and should NEVER be used to create a slurry. It's also 600 grit not 400 grit.


Chosera stones are also splash-n-go, soaking can lead to cracking of the stones.
 
Jason B. said:
The red "nagura" with the Chosera stones IS NOT A NAGURA STONE! It's a cleaning and leveling stone and should NEVER be used to create a slurry. It's also 600 grit not 400 grit.


Chosera stones are also splash-n-go, soaking can lead to cracking of the stones.
Click to expand...

Thanks Jason.
I do know the possible cracking issue, but starting with 5000 slurry greatly increases (to me) the finishing level and I found out that keeping 5k and 10k roughly 3-5 min in water greatly helps.
No cracking so far as I'm very careful.
So, why the h*** every Chosera reseller mentions that it comes with its own Nagura stone?
Just asking as I've also the Naniwa SiC stones which are expressly marketed as flattening stones...I confess I'm even more doubtful now
 
It's confusion at its finest with some lack of education mixed in. Your best bet would be a natural nagura for forming a slurry. CKTG has a Chu nagura which is about 5000 grit and can be used to form a slurry for sharpening, it's what I use.

In most cases you shouldn't need a slurry stone for the Chosera stones, they form a mud rapidly on their own while sharpening which I find to be more effective than starting one with a diamond plate or nagura. Unless you are sharpening very large bevels like those of a yanagi then forming a slurry is kinda pointless anyways.
 
"The red "nagura" with the Chosera stones IS NOT A NAGURA STONE! It's a cleaning and leveling stone and should NEVER be used to create a slurry. It's also 600 grit not 400 grit."

EXACTLY!

If you wish to generate mud on these stones, consider a tomonagura or same stone - in this case a smaller piece of Chocera stone. This is in preference to a diamond plate as the mud is exactly what you get from the stone. While you can get by without it, it's nice to use on straight razors so you start with a developed slurry. Nice but not essential.

---
Ken
 
Jason B. said:
It's confusion at its finest with some lack of education mixed in. Your best bet would be a natural nagura for forming a slurry. CKTG has a Chu nagura which is about 5000 grit and can be used to form a slurry for sharpening, it's what I use.

In most cases you shouldn't need a slurry stone for the Chosera stones, they form a mud rapidly on their own while sharpening which I find to be more effective than starting one with a diamond plate or nagura. Unless you are sharpening very large bevels like those of a yanagi then forming a slurry is kinda pointless anyways.
Click to expand...

Jason, thanks once again.
I'd like to outline that if I don't form a slurry on 5k and 10k, they load. Shouldn't this be a good indication that new material is NOT exposed?
 
ksskss said:
"The red "nagura" with the Chosera stones IS NOT A NAGURA STONE! It's a cleaning and leveling stone and should NEVER be used to create a slurry. It's also 600 grit not 400 grit."

EXACTLY!

If you wish to generate mud on these stones, consider a tomonagura or same stone - in this case a smaller piece of Chocera stone. This is in preference to a diamond plate as the mud is exactly what you get from the stone. While you can get by without it, it's nice to use on straight razors so you start with a developed slurry. Nice but not essential.

---
Ken
Click to expand...

Thanks Ken. Please see my post #10 though.

CKTG says in 10000 Chosera description "Every Chosera sharpening stone is delivered with a special Nagura stone (67 x 49 x 25 mm) to put a fine sharpening paste on the surface of the Chosera stones during use.".
I think this is a bit misleading given what has been said above.
 
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I just wanted to disclose to everyone in this thread that starting from tomorrow and up to next Friday I'll be on holidays.
I'll try to answer and say thanks to anyone than will post here, but I'm not sure whether I'll have cellular network/wi-fi coverage :(

Thanks in advance
Dan
 
daberti said:
Jason, thanks once again.
I'd like to outline that if I don't form a slurry on 5k and 10k, they load. Shouldn't this be a good indication that new material is NOT exposed?
Click to expand...

No, it's metal being removed so the stone is doing it's job. Most high grit stones will load and in most cases that's how you get the best polish from the stone. The smaller the contact area the more you will load, so as you get near the belly and tip loading just happens.

Next time you sharpen don't form a paste, just let the stone work and keep it well flushed with water. Make sure to lap your stones before use too.
 
Jason B. said:
No, it's metal being removed so the stone is doing it's job. Most high grit stones will load and in most cases that's how you get the best polish from the stone. The smaller the contact area the more you will load, so as you get near the belly and tip loading just happens.

Next time you sharpen don't form a paste, just let the stone work and keep it well flushed with water. Make sure to lap your stones before use too.
Click to expand...
HUGE thanks Jason :)
 
I was curious about this Chosera Nagura as well. I Use small DMT plates for cleaning up impacted particles, and leveling high corners. I find it funny seeing people use expensive Nagura stones on high end synthetic water stones... you simply don't need them, unless you want to clean up the surface... in which case a cheap little DMT plate is perfect.

I remember reading somewhere that when you use a nagura stone, the swarf created by the coarser nagura does not affect your sharpening too much because, the abrasive particles have been worn down and are not very sharp, while the particles on your stone are. Nagura stones can be great for adding lubrication though.
I definitely recommend a dressing stone of some kind for water stones of all types, its just necessary!
-I do have a question, if the Chosera included nagura stone is "600" grit, is that what a 600 grit chosera feels like? It certainly looks NOTHING like a chosera stone, it reminds me more of my king 1k stone, but it is not as abrasive. I've been considering using it as a pocket sharpening stone! I did manage to sharpen a knife on just that nagura its self.
 
Naniwa makes many stones including a 600 and 1000 grit Red Brick style stone that similar to but harder than King stones.
 
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