Tomo nagura and finishing on a JNAT

[blackhhawk]

JNATs are extremely interesting, but with that comes a ton of information and a skill set that seems to take a very long time to learn.

When finishing, the last part of my progression is the tomo nagura. I've come to understand that the tomo part in some way means "the same" or something along those lines. I'm guessing the stone is supposed to be a cut of the hone itself or a part of that layer. I've also heard you can just raise a slurry with a DMT and that would resemble using the tomo.

My question is, what's the best option? Do people go from the tomo to just water? I've read that finishing with the tomo slurry is good because once the slurry breaks down it leaves a great finish on the edge. Another thing in question, I've read that some people have said they were trying to find the right tomo for their stone. How do I do that? Do I need to keep buying them until I find one that works? How do I know the one I have is or isn't the best one for the job?

I'm terrible at putting my thoughts into words, so if any of this made sense to anyone, please give me some elaboration on this. I don't quite understand this part of the process.

 

[gary haywood]

I under stand what your saying..it seems to me the more I read on j nats the more complicated they seem, but in reality there not that complicated I just used my nakayama with slurry to water or even misty slurry... I carn't answer about the naguras so i'll leave that to more experienced j nat honers...

 

[Doc226]

I am not a JNAT expert, I am just an end user.

Like you, I think tomo means "smae" or "Frined" and most of the time the best tomo is from the same cloth as the base stone.

As far as finishing, I have finished on plain water after really washing the stone and the blade, this method works well for some stones but not others. Lately I have been finishing with a mist of slurry and that seems to work a tad better. What I do after honing and the slurry is really worked and broken down is rinsing the stone but not the blade, this leaves just a tad of slurry, adn I dilute that once.

As far as picking the correct tomo, that is really trial and error. I do like using a DMT card to raise the slurry the first few times I use a new stone, this IMO is the best way to find that stones full potential since you are raising the truest tomo slurry possible. Warning, there is a risk of a diamond being released in to the slurry and messing up your edge-has not happened to me but it is possible. After finding out the true potential of your stone, fins a tomo that works for it. Ideally same characteristics as the stone but does not have to be.

Lastly unless you are honing a ton of blade by raising the slurry with a diamond plate don't worry about wearing out your stone prematurely. I have one stone I only use a DMT card to raise slurry and that stone will outlive me, my children and their children. This stone is a softer stone, so using the diamond gives me the added benefit of "lapping" every single time.

 

[oakeshott]

What Doc and Gary said. While becoming an "expert" in Jnats is a long, long apprenticeship, it's really pretty easy to get very good edges pretty quickly. The thing you'll find is that there really are no "rules". Guidelines maybe, but no rules. I've read here that some people finish on slurry and some on water. Some will do both, but it depends on the stone or the stone and the blade. The key is to try all of it and check your results. If you do that, then you'll come up with general patterns that give you good results.

You may need to go through a few Nagura to find the one that works best with your stone. Or rather, the one that works best for YOU for your stone.

 

[Brooksie967]

Ahh yes the question about finishing on water only.
Honestly, the only answer I can give is that it depends on the stone. I want to badly to be able to unlock the secrets of finishing on water with my big hard and fine ozuku but almost every time is leaves a harsh edge. With slurry it produces incredibly sharp and smooth edges.

A few of my softer stones (and I'm not sure if that has something to do with it) are quite capable at finishing on water only but I still prefer the smoothed shaving sensation that a razor, in my kitchen, only achieves when finishing with slurry.

 

[jpcwon]

I am nowhere even close to being proficient at JNATS, but I have experimented with slurry finishing & water finishing. I personally find that my face prefers if I finish on a slurry-tinged water versus pure water. I will raise a "skim milk" slurry with my tomo and hone on that until it breaks down. I will then dilute the slurry out quite a bit so that it's mostly water and finish on that (kind of like misty slurry)....I don't know why I don't have good luck finishing on pure water, but alas....

 

[SliceOfLife]

Depends on your stone and depends on your tomo. Try both and see which you prefer. The only "authoritative" words I remember reading on this was some old timer Japanese barber wrote a paper on sharpening razors and said to do a handful of passes (under 10 if I remember) on water after rinsing the tomo slurry off as a final step. The paper was posted at one of the Jnat sellers sites, (I wanna say it might be japan-tool?) awhile back.

 

[Gamma]

Finishing, honing in general actually, on any stone - has more to do with technique, skill, and experience than anything else.

The tomo, if it is of good quality, will be either the last step or the next to last stage. Many use water only to finish but many finish on slurry too.
Some people don't use a Tomo - but that's another story.

Rarely is the Tomo actually a piece of the Honzan - usually it's a high-quality piece of another stone. Possibly the same type from the same strata but that is not written in stone.
I use Namito Kita Tomos on Tomae Asagi Awase all the time. I use Suita Tomos on other non-Suita stones as well.
There are no rules here. To believe there are a hard-fast rules here cements a limited point of view into place; one that can seriously impede progress.

The stone will perform only as well as the user is capable of. Along with that - selecting a Tomo that allows the user to maximize their efforts on that stone is critical.
IMO - The combination of the Tomo and the Awase is secondary limiting factor that follows the limiting nature of the users skills.
In other words, what I find is that the User/Awase/Tomo combination is what determines the final outcome.

I've experienced significant gains in stone-performance by choosing another Tomo. But - this was only understandable after I had exhausted the capabilities of the initial set up.

BTW - the differences between two Tomos can be fairly nuancial. It might not be a good idea to think that a new Tomo is going to bring on a huge and significant increase in performance. That can happen, but I wouldn't rely on that happening unless the original Tomo just isn't working well at all. Occasionally - a really great Tomo/Stone combo presents itself though too - those moments have been far and few between for me though. Mostly - it's about incremental changes. Most significant improvements come about via the users skills getting better.

People use DMTs for Tomos. I try to avoid doing so, notably, the Iwasaki group does not use diamond Naguras either. I assume they know a few things about sharpening. I think a better choice for a DN is an Atoma - but they're pricey options. I have one and I use it only on very rare occasions.
Factually - the slurry raised by a DMT is not the same as that raised by a Tomo cut from the same stone or from another stone. This does change the action of the slurry on the stone. Also - I've had diamonds pop off DMTs when doing this and I lost a very well done edge as a result. I'm not the only person this has happened to either. Sometimes - I put a ton or work into an edge and taking a chunk out of it at the finish isn't something I'm fond of dealing with.

Whether or not any of that matters to you, or anyone, is personal choice. I choose to work one way - that doesn't mean I'm right or wrong. Logic is what it is though, and facts are facts. From my perspective - creating a slurry that starts off being more coarse doesn't seem like a logical thing to do unless there is no alternative. But - that's just for me and I do have a lot of Tomos here so it's easy for me to take that position I guess.

IMO - matching, or finding 'the' Tomo is trial and error - there is no other way.
Learning to use the one you have is the first step. Once you know it - really know how it - and the stone work together - only then can you hope to successfully find another that 'may' be 'better' for you and the Awase.

You can't compare until you've maxed out your understanding of the existing stone set-up.
It just can't be done effectively - physically - it can be done, but doing so is more like chasing your tail.


One of the biggest mistakes I read about on the internet is when someone buys a Jnat thinking it's an add-water-and-stir method of honing.
It's not that at all. Moreso with Jnats than other systems I think, but it's certainly not exclusive to Jnats.
Most things need to be learned, I haven't met anyone born with razor honing skills - not yet anyway.
Someone can buy a $10k Jnat and they are not going to get a $10k edge.
They might not even get a great edge unless they really have their game on.
Buying a $50 Tomo might not make anything better today. Next week, or next year even. But it could. You never know.

Sorting these things out takes time - as in a good long while and a lot of patience/practice.

End of story.
Sorry for the seemingly endless littany; it is, no doubt - the result of too much coffee and a 'Little Debbies Fudge Round' snack cake.

 

[buca3152]

Well said. As you progress, take note of what doesn't work and don't do it again! LOL. Be aware of changes you make and the results you get from them. Not to turn it into a classroom, but doing the same thing over and over will probably not get a different result. As was said, there are no rules, but guidelines that mean squat until you've tried it and know that it doesn't work or does work. Synthetics have the advantage of consistency, but its cool when you figure these things out at least enough so to enjoy a great shave with one.

 

[Steve56]

As far as matching naguras to a finisher, I've been working on a method(s) that may help. Keep in mind I've just begun trying the following methods so the jury is still out, but any and all input would be extremely welcome.

The first criterion for a tomo to me is hardness. If the tomo is too hard, I get all aswedo slurry, and if too soft, I get all "tomo" slurry. To me, it's only a real tomo if the slurry is about 1/2 and 1/2, as it would be using a piece of the same aswedo as a tomo nagura. Otherwise, you just have a nagura progression of sorts or the equivalent of a diamond plate. The second criteria is fineness. On a finisher, the tomo needs to be at least as fine as the finisher. If not, there isn't much point in it unless its a part of a progression and therefore not "tomo".

To test hardness, see the image. I'm using squares of white lint-free shop towels. I raise a slurry with an Atoma plate off the aswedo (an Ozuku in this case) and off each nagura I'm testing, wipe the slurry on a cloth and let it dry. It does need to be dry. Then I do the same with the nagura and aswedo, and compare the colors. If I get a color in between, I'm where I want to be. Obviously, if the tomo and the aswedo are the same color or very close, that complicates matters. The hard kiita so far tests good and works the best with the Ozuku though the color is faint in the image. The little Ozuku nagura is still in testing.

Next, I'd want to see a scratch pattern though shaving can do the same thing. If the shave is worse with one nagura versus another, you have your answer.

So yes, it's a lot of trial and error since you actually have to have naguras in-hand to determine suitability no matter what method you use, but I think there are things that can help.

And the two criteria I mentioned, hardness and fineness is not the only factors apparently. I know Alex has a video using an akepin, usually softer and coarser, to make a usable slurry on a harder stone. So at some point, yes you just have to try them, and shaving is where the rubber meets the road.

Cheers, Steve

 

[buca3152]

Very nice job. You laid it all out very well.

 

[jpcwon]

That's a very good method, Steve! I'll have to try that sometime. I've had difficulty matching a Tomo to my hard Ozuku Asagi in the past, trying to get a "half and half" mixture of Awasedo and tomo slurry. I have tried several different tomos, and they're either soft (ie: kiita tomo) or too hard (another Ozuku tomo...very hard to raise a slurry with this one). I settled on the softer Kiita tomo as I got better shaves when using it in conjunction with the Ozuku. Almost none of the slurry is from the Ozuku itself, but the resulting edge is usually pretty good.

 

[Steve56]

Hi jpcwon,

I think it's a decent relative hardness test, and a stone can't be tomo in my mind if the hardness is way off. That doesn't mean the nagura is not good or just as useful, it just means it isn't tomo in the sense traditionally meant. Fineness is harder to quantify and shave readiness has to be done by trial and error since there are additional variables like beard and skin types that affect what shave worthy means.

I'm an ex-engineer type and the idea that there isn't anything useful beside trial and error bothers me so I have to try and figure out how I can get some additional information.

Here's another image of the test I originally used to help identify that hard kiita as a good candidate for the Ozuku out of 4 total - above I'm testing the Ozuku nagura. You can see better the kiita and Ozuku slurry is about half between. The top line of swatches is nagura slurry from an Atoma plate. The circled center is the Ozuku slurry from an Atoma plate and "blue", murasaki, and "green" on the bottom line are nagura+Ozuku slurry of the naguras I was testing. The murasaki is soft enough that it's all I get and the edge isn't much different than just using the murasaki to begin with.

Edit: I ended up choosing the kiita out of this lot even though the green one is close in hardness, The green one is quite small, and the kitta was large enough to get a pocket knife blade on, so I could inspect the edge and tell by polish it was about as fine as the Ozuku.

Cheers, Steve

 

[Gamma]

The favored method, albeit not entirely accurate in many regards - for determining stone hardness is the water drop test.
To compare several stones at once - watching how long it takes a drop a water soak in can tell you 'some' things.
Other factors become inportant here - but in a relative sense this is a pretty good way to make a quick and easy assesment.
For myself - I can tell during lapping.

After that - judging how fine the slurry is becomes a primary condideration.
It's said that most Jnats all have the same basic particle size. If that's to be accepted as truth, then the question becomes how fine does the slurry break down, and at what rate.
This really can't be judged too well with a simple on-site one-off test. At least I don't think it can.
There are many variables at play - pressure, length of stroke, type of steel, existing wear on the steel, etc.
Better I think to determine this slowly - over several or many uses.
It's entirely possible that a very soft Tomo can kick up a lot of the Awase because of exceptional abrasive power.
Anyone's needs can determine their opinion about what is or is not a good Tomo - my only requirement is that the Tomo gets me where I want to go. This - is what's I've been taught. It is not a rule or a declaration of truth. Well - it's my truth I guess.

About slurry mix - I don't know that a 50% is or is not ideal to be honest. I can say for certain that while I know there's a need for a mix - I've never considered the proportions. As along as I see both the Tomo and the Awase in the slurry I'm good.
I'm more in favor of rotating Tomos in and out of progressions and seeing what goes on. The process of elimination that way seems pretty effective.

There is way more to the action of the stone with the slurry than just numbers and an initial acertation.
The Awase's grinding power has a lot to do with how the slurry breaks, as does the grinding power of the slurry.
The friability of the particles, along with their cutting power and so one - that all factors in.
Counterintuitively - most slurries seem to do a better job when wetter than they do drier. This too adds a curveball in to the mix.
For example - if my slurry is wetter than your slurry and it works better - it's entirely plausible that I might think its working better because of the proportion of Tomo to Awase than how wet it is.
I believe this to be a common thing that happens - and a big area of confusion too. Add in the rest of the variables and it becomes a hodge-podge. I really do think that consistent trial-error will bring the most valuable conclusions at the end.
At the start - any method of testing that gets the user deeper into their stones is good I think.


There's an interaction between slurry and stone - one I see/feel but can't clearly quantify accurately. Some slurry breaks slow, others fast. Some seem to go on and on while others seem to hit a mark and just die. I've had high grade Awase Tomos from broken stones that set edges back on blades honed on mid-tier rocks. Move that Tomo to another Awase and bam.... heaven. Go figure.
And - I've had Tomos just stop being a favored stone - they've seemed to become problematic or just less effective.
Sorta like an Awase that gets lapped and a new less-effective or problematic layer is revealed.

The scratch patterns at the end of a cycle may be important - but not so much at the beginning.
Truthfully - I'm more concerned about where the Tomo goes, than I am about where it starts.

 

[alx gilmore]

A lot of good information and thoughts here. Steve, your color swatch samples of slurry are very eye opening and easy to understand. The word tomonagura means "matching" or "compatable" or even "friendly". And as Gamma said you need to test out the combinations as you go along and then go back later to reconfirm those matches. One problem with tomonagura is that they have to be made from quality and expensive stones, its a hard decision to cut up a really super quality stone into small pieces. I do it but it is always a tough decision.

I have said this before, that I look at honing a razor as being a lot like baking a cake. There are 3 main elements necessary to have a successful outcome. If you go cheap on any of those elements you end up with failure or a cheap tasteless (dull) product. #1 is the skill of the baker. #2 is the recipe. #3 is the quality of the ingredients. If you short yourself in any of these elements you are shorting the final product. If you substitute margarine for butter, or cheap chocolate instead of better grades, or tasteless apples for the apple pie, no matter how much sugar you add to overcome the lack of those flavors, it is never the same.

The base stone is very important, the main ingredient. If you add into the mix a tomonagura as an ingredient it can detract or enhance the final result. The skill of the user can overcome some shortcomings by adjusting the technique if the tomo is off, but in the long run the craftsperson will fine tune the ingredients further instead of changing the recipe. This is why professional sharpeners in a busy shop setting will cherish the stones in their quiver and is also why they will build their quiver with larger size stones so that once they have an acceptable match to their most often used steels they can then present with confidence their final results to their customers knowing that the same task and quality outcome can be repeated at a later date.

For the hobbiest this is not such a big deal, and the fun for the hobbiest is collecting and trying out different combos, stones don't wear out due to low volume useage, etc.. I think Gamma and Steve and others are smart to have the best quality stones they can find and then have the tomonaguras on hand to match-up for better outcomes, more often.

Alx

 

[blackhhawk]

Holy cow, I forgot I made this thread so I haven't checked back. Thanks for the responses, I'm still reading through them.

I can say, out of my experience, that finishing on water gave me a harsher edge than with the tomo. If I had done 10 or less laps like the japanese barber wrote, then who knows, maybe I'll give that a shot next.

One thing I think I've been doing a good job of is not buying more hones. I replaced my king with a chosera, but that was a no brainer. I'm going to continue to use my JNAT and not buy any other JNATs for a while, until I feel that I have a better understanding of honing with it.

Thanks everyone, I need to finish reading this stuff when I get home from work.

 

[Attila]

I also finish on a very, very finely broken down Tomo slurry to the point that my Jnat is almost (but not quite) dry. Generally I will do at least 3 refreshes of the slurry and have gone up to 5. This works very well with what I am using. Water only on my stone has not given me good results.

 

[buca3152]

I have never tried refreshing more than twice. Must try is all I have to say.

 

[blackhhawk]

Yeah I originally finished on tomo, refreshing before break down a few times and then finishing finally on the broken down slurry. I didn't get the keenness I was after, though I believe that was more so due to my bevel not being set all the way. When I tried on water after that it did result in a sharp edge but it was harsh. I did around 50 laps though. I wonder if just ten would do something without making it harsh.

 

[Attila]

I have never tried refreshing more than twice. Must try is all I have to say.

This tip was given to me by a local guy who is REALLY quite proficient at using a Jnat. That and holding the Jnat in your hand to better feel the strokes and adjust to keep the slurry contacting the blade at all times as well as letting each slurry session go almost dry on the hone before you refresh. His results didn't lie on a blade he sharpened for me, to say the least. I incorporated his techniques and man, do they ever work!

I did two sessions on a full progression of Nagura except the one before the Tomo, only one there and then 5 with the Tomo. Got a really, really nice edge, this after glassing the edge on a Fili 14. I'm still learning but the edge I got in the end on that Fili was wonderful to shave with.