Thread: Shoobie Doobie Asagi

Originally Posted by onimaru55

First pic is wet, medium hard stone.
The second picture is a dry, very hard stone.

I want to see the reflection of light when your stone is dry.

The first picture just shows the reflection of light of the water/air surface and not of the stone.

Is this what you mean ?

Originally Posted by onimaru55

Is this what you mean ?

Yes.

I see some light scatter on the mirror image.
The stone itself look a bit milky too.
The surface is decent smooth but you still have small scratches caused by diamond stone.

I think you can get better results with this stone if you smooth it with another Jnats you have.

Thank you, I have tried already in the past & found no extra benefit. Whatever small scratches there are get filled in by the slurry & when used with plain water there is no degradation of the edge. I realise there are 2 schools of thought on this & this is just my experience.

Originally Posted by onimaru55

Thank you, I have tried already in the past & found no extra benefit. Whatever small scratches there are get filled in by the slurry & when used with plain water there is no degradation of the edge. I realise there are 2 schools of thought on this & this is just my experience.

Yes you are right there are 2 schools in Japan one is of using Jnat stones with knife and tools where you use a lot of pressure on the stone and particles break very fast under pressure and larger surface
Then they are razor and sword honing where you need you stone as smooth as possible and they use only naguras or other natural stones to flatten stones.
With sward because they dont want any loose diamonds to scratch they finish and for razors because there is no pressure when honing and very small sharpening surface.

Niiiice!

Yep, I love J-Nat edges, my Maruichi is far and away my favourite finisher.

Originally Posted by Stubear

Niiiice!

Yep, I love J-Nat edges, my Maruichi is far and away my favourite finisher.

Yes Maruichi is just a brand, you can get cheap Ohira or Takashima for much less and same quality.

Originally Posted by hi_bud_gl

i bought one of those too.
I hope it will act same as your describe Rich(i hope i didn't mess up name). if not i am sending it to you and you got to cover the damage.
have fun.

Ha, I think you'll like. It's a very fine finisher. The big thing with these ultra hard J nats is the finish you put on it. It must have a glass like finish, I took mine to 1000 grit sandpaper....

I don't recommend using a DMT plate to raise a slurry, It can mess up the finish of the stone, IMHO, YMMV.

I would use Tomonagura to raise slurry on this type of hone. Also, they excell at the Nagura sharpening system.

Rich

Originally Posted by onimaru55

TI realise there are 2 schools of thought on this & this is just my experience.

I do not think that there are 2 schools.

Just let me explain it with a analogy.

There is a Joe living in a "Small Village".
There is a other villages 10 miles away.
Lets call it West Village.

Now there is a globetrotter North who lives in San Francisco who often travel to Tokyo.

There is another globetrotter South who lives in Sydney and travel to Johannesburg South Africa.
These 3 guys make a discussion on a forum

"What is the shortest pass going west from point A to B"

Joe writes in the forum:
"Just head west. In my experience going from my Small Village to West Village you just head west. That is the shortest pass. "

West Village <<<<<<< heading west from Small Village
10 miles

To this globetrotter North replies:

"No No ! you are wrong. When I fly from SFO to NRT the plane head northwest first, then go west and finally it goes southwest.
Look at this picture

This is the shortest pass."

Now comes the globetrotter South
"No No! You two guys are wrong. If I fly from SYD to JND I head southwest then west and finally to northwest. That's my experience with a Qantas flight."

These 3 guys discussed and discussed and all 3 guys insisted in their personal experience.

Joe comes to conclusion to agree for disagree and said:
"there are 3 schools"

The question here is "Is Joe right?"

No Joe was wrong!
If Joe had some insight of geometry he would know that the shortest pass on a sphere is a great circle and all three are talking about the great circle.
Great circle - Wikipedia, the free encyclopedia

Now lets go back to the lapping and smoothing discussion of hard Jnats.

Onimaru-san knows that a smooth surface is needed for final lapping.
He writes:

Actually my current Atoma is only 7 months old. I sold my well used one

So he knows that DMT #325 makes bigger scratches, a new Atoma 1200 medium scratches, a 7 month old make smaller scratches and the very old Atoma 1200 is best of all.

This experience and observation is in line what I am saying. You must have a smooth surface of the stone.

Oniomaru-san writes also:

Whatever small scratches there are get filled in by the slurry & when used with plain water there is no degradation of the edge.

This is the same as I write the softer the stone more tolerance to scratches made by diamonds.

If you have a very hard stone like the very hard shoubu discussed in this thread I recommend to make the surface as smooth as possible.

It is the same as the discussion of the 3 guys about the shortest pass A to B.

If you go 10 miles just heading west is right. If you go 5000miles you must head more north if it is in northern hemisphere.

How much north will depend where you start and the distance.

It the same as how much smooth depend on how much hard the Jnats is.

I just hope everyone understand it.

I think i had too many drams tonite to figure out the above statement