Jnats, how to get the most out of them?

[Stapelfeld]

I have a Tsushima stone. The seller says it’s between 3,000 grit and 6,000 grit.

Before someone says anything both the seller and myself know that the grit system is not the same for synthetics and natural whetstones, in this case a jnat.

However, how can I get the best “highest grit” polishing from my Tsushima, by making a slurry and working it down or by water only and doing more laps?

Thanks in advance friends.

*I want to make a note that I know naguras might help but i'm only interested in this question when it comes to the base stone and perhaps a diamond slurry made from the base stone*

 

[silverlifter]

It really depends. Are you going to the JNat from a bevel set at 1-2K, or are you doing mid-range work on another synthetic(s)?

If the former, I'd start with a diamond slurry and work until just water then inspect, test, and shave.

 

[Stapelfeld]

It really depends. Are you going to the JNat from a bevel set at 1-2K, or are you doing mid-range work on another synthetic(s)?

If the former, I'd start with a diamond slurry and work until just water then inspect, test, and shave.

I usually bevel set with a shapton 1.5k ha no kuromaku then jump into the tsuschima.

 

[Gamma]

Hone a lot on them. Hone every day. Hone till it hurts then hone some more.
The only way to know the stone is to use the stone.
The more you use it, the more you will know.

 

[Stapelfeld]

Hone a lot on them. Hone every day. Hone till it hurts then hone some more.
The only way to know the stone is to use the stone.
The more you use it, the more you will know.

Will do sir! Bought a cheap GD just to hone on the tsushima.

 

[Steve56]

Finish at normal pressure, then lighten up and go to ‘short’ strokes. See Iwasaki’s paper for the reason.

A. clear water finish will give you a sharper edge

 

[Stapelfeld]

Finish at normal pressure, then lighten up and go to ‘short’ strokes. See Iwasaki’s paper for the reason.

A. clear water finish will give you a sharper edge

Thank you Steve! I will review Iwasakis paper.

 

[JPO]

I like to use my Tsushima Nagura bench stone with a liberal amount of slurry. I don’t dilute the slurry too much. Slurry acts as lubrication. I don’t find any benefits in diluting to water. I can usually get by with just some koma and tomo slurry on my finisher afterwards.
Koma also works really well on my Tsushima. I also get good results with other asano naguras.
You have to figure out what you like to use with your Tsushima stone.
It will also depend on how much work you are doing.
I like to use it as my first stone if I just do maintenance honing.
You just need to try stuff out.
My particular stone is quite hard. This gives a really precise edge. A softer stone might need a different approach.

 

[lightfoot]

Getting the most out of the stone could mean a lot of things.

What are your expectations from the stone? What is it not doing that you want it to do?

 

[H Brad Boonshaft]

Remember that it is a natural stone, and as such your stone may finish different from mine or anyone else’s.

I have both a Tsushima base stone and a nagura. My base stone is more aggressive than the nagura. I prefer to use the Tsushima nagura to make slurry on a Jnat base stone. It is aggressive and can break down to a fine polish.

I use a light, not a heavy slurry. When the slurry starts to dry out add some water to the stone, do a couple of laps to mix the slurry, then wipe off half the slurry with a damp sponge, add more water and hone on the 50% slurry. Keep diluting by half.

Experiment, some stones will finish well on water some on very thin, misty slurry.

 

[Stapelfeld]

I like to use my Tsushima Nagura bench stone with a liberal amount of slurry. I don’t dilute the slurry too much. Slurry acts as lubrication. I don’t find any benefits in diluting to water. I can usually get by with just some koma and tomo slurry on my finisher afterwards.
Koma also works really well on my Tsushima. I also get good results with other asano naguras.
You have to figure out what you like to use with your Tsushima stone.
It will also depend on how much work you are doing.
I like to use it as my first stone if I just do maintenance honing.
You just need to try stuff out.
My particular stone is quite hard. This gives a really precise edge. A softer stone might need a different approach.

So far I’m using it for maintenance work as well. If I have a razor that was shave ready and I’m going to rehone it because I either want to or the edge isn’t where I want it anymore then instead of going to bevel setting I go to the Tsushima. However I wasn’t sure if creating a slurry with diamond nagura was helping or just taking me back further down.

 

[Stapelfeld]

Getting the most out of the stone could mean a lot of things.

What are your expectations from the stone? What is it not doing that you want it to do?

The seller said it would be somewhere similar around 3k to 6k when compared to a synthetic. So I expect it to perform somewhere around that area in the edge quality and from what I’ve read the Tsushima stones are fairly consistent with the odd duck that is finer than most.

Yesterday I had a hone session and I was comparing the edge to a 5k shapton. I eventually got it to match the 5k but was unsure if the slurry was helping or if it was time to dilute down and work on a cleaner slurry.

But in general it’s not so much about this one stone rather the general use of Japanese naturals. I have questions like:

Are all Japanese stones the same in the sense that all will get finer with water only?

Or

Are all Japanese stones so different that with a tomo nagura or diamond slurry they all have different effects? In the sense that some might get finer while others get sent back in the edge quality?

These are some of the questions that haunt me, I’m actively testing them out and seeing what works which each individual stone but I wanted to pick the brains of everyone in the forum since I know there are a lot of people here that hold a lot of knowledge in the subject.

 

[SliceOfLife]

Do you want to use them as a way of life/one base stone whole process solution/mojo source? Do what Gamma says. Trial and error and hone till you can't hone any more.

Want to get a great edge out of them? Buy an easy one and do your bevel-midrange work on something made for it.

I found Jnat Nagura series even less efficient than Dilucot when I did it... and I haven't done dilucot in 10+ years. Maybe I didn't get good enough at it... but it struck me as not an efficiency thing and more of a -you must think there's some improvement in the final edge to justify the amount of work put in- or else a -you actually like honing as some kind of samurai meditative zen activity and WANT to spend a load of time on it- thing.
Nothing wrong with those perspectives... when I was a younger man, sure I could get into that. These days... I hone on dish-soap on stones I know hone better with oil because I happen to be in my kitchen and my oil is in my pantry (15 steps away). No time for zen. I just want sharp.

 

[lightfoot]

Regardless of diamond or Nagura slurry I like to do 3-4 separate slurry cycles to get a read on performance. I find the need to reserve evaluating the results until the end of all 3-4 cycles.

I make each slurry a little lighter than the previous effort. I also work down to misty slurry each time and a very short duration on water only on the last cycle.

By the end of the effort you may begin to get a good impression of the stone and slurry combination.

Try to do your evaluations from the same starting point in terms of the synthetic used prior to the natural.

 

[JPO]

So far I’m using it for maintenance work as well. If I have a razor that was shave ready and I’m going to rehone it because I either want to or the edge isn’t where I want it anymore then instead of going to bevel setting I go to the Tsushima. However I wasn’t sure if creating a slurry with diamond nagura was helping or just taking me back further down.

I am not a big fan of diamond plate slurry. You just have to try a few things.
All my awasedo jnat's are significantly faster with diamond slurry then my Tsushima.
I don't save any time using it over just doing some extra nagura work. It's just a different experience.
I just use it to get a different feeling edge off my final finisher.
For me the midrange work is just as important as my finishing work.

 

[Stapelfeld]

Regardless of diamond or Nagura slurry I like to do 3-4 separate slurry cycles to get a read on performance. I find the need to reserve evaluating the results until the end of all 3-4 cycles.

I make each slurry a little lighter than the previous effort. I also work down to misty slurry each time and a very short duration on water only on the last cycle.

By the end of the effort you may begin to get a good impression of the stone and slurry combination.

Try to do your evaluations from the same starting point in terms of the synthetic used prior to the natural.

Different cycles sounds like a good plan. I will add that to my honing as well as just practicing a lot with the stones.

 

[Stapelfeld]

I am not a big fan of diamond plate slurry. You just have to try a few things.
All my awasedo jnat's are significantly faster with diamond slurry then my Tsushima.
I don't save any time using it over just doing some extra nagura work. It's just a different experience.
I just use it to get a different feeling edge off my final finisher.
For me the midrange work is just as important as my finishing work.

One of the reasons for buying the Tsushima bench stone was for doing really well done mid range work. I agree with you that mid range is just as important. Just trying to get there with the Tsushima. To clarify because it’s not just about the Tsushima, that was just an example. Different jnats benefit from water only while others benefit from slurry? There isn’t a pattern?

 

[JPO]

One of the reasons for buying the Tsushima bench stone was for doing really well done mid range work. I agree with you that mid range is just as important. Just trying to get there with the Tsushima. To clarify because it’s not just about the Tsushima, that was just an example. Different jnats benefit from water only while others benefit from slurry? There isn’t a pattern?

I have one shiro suita and a lv 3.5 Shobudani. Both of these works best for me with a freshly lapped surface and a minimum amount of water. The grit released from the stone is enough to get them cutting fast.
These are the types of stones that can be really versatile with knifes, because you are in control just by playing with the pressure.
They can be a little tricky to use with razors, but once you figured them out they can be useful for midrange work.
Every stone needs to be handled slightly different.
You just have to use them.

 

[H Brad Boonshaft]

So, one of the ways you can hone/finish is a two-step process, refine the bevels with a thick-er slurry, (e.g. remove deep stria or lay down a Kasumi pattern over a synthetic bevel), then thin the slurry to refine the edge once the bevels are where you like them.

Yes, I know this happens normally when we thin slurry, but I am talking about intentionally working the edge separately, much like honing slower and shorter strokes, makes a lighter stroke, it is intentional. Try it, might work for you.

A thick slurry will impact the edge and damage it but will cut faster.

Last, try water only, either rinse off the water, (I use a lab rinse bottle not spray), dunk the stone in a pond or under running water. The three techniques can have different finishing qualities.

I find that water only, (under running water) will make an edge keener (on the same stone) and a bit harsh, while the same edge will shave well honed with just flooding, rinsing off slurry. I suspect just a bit of slurry remains to cushion the stone face and not allow the stone to cut as deep.

It is just experimentation and getting to know your stone. If a stone can finish on water is very stone dependent. Some of my Jnat finishers can, some cannot.

Diamond slurry works on Jnats for me, but diamond slurry on Slates and Coticules not as well as slurry stones. I believe that Jnat slurry breaks down faster and finer. On some stones Jnat diamond slurry finishes better than nagura, and I have 20-30 nagura, and Mikawa nagura.

Mikawa seems to work better on hard Jnats for me, a finer and more comfortable edge. I rarely hone on Mikawa slurry.

 

[Stapelfeld]

I have one shiro suita and a lv 3.5 Shobudani. Both of these works best for me with a freshly lapped surface and a minimum amount of water. The grit released from the stone is enough to get them cutting fast.
These are the types of stones that can be really versatile with knifes, because you are in control just by playing with the pressure.
They can be a little tricky to use with razors, but once you figured them out they can be useful for midrange work.
Every stone needs to be handled slightly different.
You just have to use them.

When buying a new stone. What goes through your mind when trying them and testing them? I hope that isn’t a hard general question that is impossible to answer. Thanks JPO