Thread: J-Nat Honing

I didn't want to highjack a different thread, so I'm starting my own on J-Nat techniques. Two goals: one to share my approach, which has led to excellent, comfortable edges. Secondly to look for other methods to work from my stones... I need suggestions and a (semi) organized approach.

My initial route to keen edges: With a dull razor start using a synthetic bevel setter. I then used a very hard base stone, that was known as a solid finisher. I then used asano nagura to raise a slurry and work a progression... botan -> tenjyou -> mejiro -> koma. I finished with a tomo raised slurry, diluting down to water only laps.

I started altering that, however, by doing a 4K -> 8K synth, and then jumping into the nagura progression at the mejiro or koma. It was faster (although using nagura is pleasant, the entire progression would take well over an hour), and starting with a mirror edge provided a base to ensure I was working the entire edge when it would start to haze.

Picture time:



The base stones are on bottom with the various nagura on top. Base stones, left to right, are a tsushima black (facedown), kiita (hard, unknown), shobudanai, and two ozukus.

My first edges using the progression on the shobudanai were pretty good, roughly as keen as my 12000 SS but also with a "soft" feel on the skin... it wicked the hairs away but was more forgiving on the skin, leaving few weepers or cuts. The tsushima black was pretty cheap, and works pretty cheaper. Not a finisher... it's a mid grade stone. I haven't played with its nagura much. The kiita is fairly hard, and self-slurries when honing. It produces a good edge, but not as keen as the shobu. The ozukus I purchased trying for something similar to the shobu, but larger. The first one I received (far right) I discovered a hairline crack going about halfway through the stone after flattening and sharpening my first razor on it... the vendor sent me a replacement, and generously let me keep the original. Some CA glue fixed the crack, and after flattening I now have two ozukus... both give excellent edges.

My "goto" approach now is to use the ozukus as the base stone, starting with an 8K synthetic edge. I use the tomo on the far right in the photo to slurry and then dilute down to water. This provides very good edges, easily exceeding my SS 12000 both in keenness and comfort.

The shobu I'm pretty good on what it can do for me... it's a fine stone, but maybe not quite as fine as the ozukus, and small enough to make me wish I had a bigger hone every time I use it. Probably coming to a for sale page near you in the future. The kiita and tsushima I kind of don't know what to do with. Same for all the tomo to the left of the lacquered asanos...

I will probably start experimenting with self-slurries, raised with a diamond plate, in the near future on the kiita and ozukus. Any other suggestions/techniques folks have to share?

I’ve used several progressions much like the ones that you have described. All worked reasonably well.

Currently, my usual progression is Shapton Glass HR to 4k, a fast kiita with diamond plate slurry, then a finisher with very light slurry from a tomo nagura. My idea is to set the bevel with a 2k Glass HR (my normal bevel setter because it’s so fast), testing by inspection with a loupe, then 4k Shapton Glass HR followed by a light stropping and testing for bevel set with HHT. If the razor passes HHT really well at 4k to 6k, then I am just minutes away from a fine shaving edge. The idea behind putting the fast kiita between the mid grit synth and the finisher is to make a transition from a synthetic scratch pattern and the finisher without taxing the Jnat finisher so much.

I’m also testing a 6k Shapton Glass HC - the grey one for carbon steel - in place of the fast kiita but I have no definite conclusions yet but it seems to work, both by inspection and shave testing, but I just haven’t had enough time with it yet to say for sure, I only got it a few days ago. The Glass stones support 3x grit steps according to Shapton, and that’s been my experience too. So I’m trying out HR 2k (bevel set), 6k HC, then finisher.

The fast jnat between the mid grit and the finisher seemed more useful when I was using Shapton Pros vs the Glass, the Pros can leave some distinct scratches.

I’ve also used and still use Mikawa progressions, like you say, fun but slow. I’ve also used a fast koma between the mid grit and the finisher, as well as diamond plate slurry on the finisher. Either seems workable depending on the stones of course. I recently acquired some NOS or near NOS Swedish razors, a couple of E. A. Bergs that have the hardest steel that I’ve ever encountered. They were resisting taking the ‘butterknife’ edge, and I suspected that they simply needed more honing, so after 4k I used a 3-Mikawa progression followed by a tomo on the finisher and that worked quite well. Sometimes with naturals you just have to try stuff.

To summarize, several methods have gotten me from a set bevel on a mid grit synth to ready to finish, one or more Mikawa, a fast jnat with diamond slurry, or an extra diamond slurry before tomo slurry on the finisher. All seem to work reasonably well, again depending on the specific stones.

I’m working with several different progressions currently, looking to establish a most efficient “go-to” method. What’s working best for me across all steels is a synthetic bevel set and scratch reduction regimen that starts with Shapton Glass 2k, Naniwa Hayabusa 4k, Naniwa Snow White 8k- JNATs.

At the transition point from synthetic to JNAT is where much recent experimentation has come into play. The most fun honing experience includes a couple mid-pre finishers before working into full Nagura progressions. The most efficient seems to be simply skipping the mid-pre finishers and jumping directly into the finishing progressions. The benefit of including the extra stones is a less intensive and time-consuming session with the Nagura progressions. That is: instead of 10+min with each slurry I can spend 4-6min and then work into final finishing with tomonagura. However I’ve found that deeper scratches are persistent and using the extra stones brings more thorough scratch reduction.

I am fortunate enough to also have a Shapton Glass 16k and a Shapton Traditional 30k. These have served quite well to establish a sort of “control group” edge from which I can eliminate or isolate scratch patterns and establish what’s happening with these progressions. Checking my work as i polish up to 30k shows effects of adjustments in the process, and that gives me some level of confidence in my analysis so I can spend less time attempting to measure sharpness and focus on visual evidence given through the loupe.

Once satisfied with uniformity if scratch patterns or striations, and quality of level of polish, I can conduct sharpness tests that correlate to these observations. Making my adjustments based on this process has improved performance for each razor. However I’ve spent an awful lot of time working on this and I’m afraid my methods are not fast. Since my current goal is performance regardless of effort, I am quite satisfied with the progress.

Despite all the current experimentation I remain open minded to try new things. I’m looking forward to hopefully learning more in this thread.

I went back to my kiita today... It is faster than the other finishers (shobudanai and the ozukus), I'll see what edge I can max out on that. My plan right now is to shave off that, then test the tsushima black. As Steve56 suggests, I may be able to get a relatively quick progression of tsushima (with it's tomo), my kiita, then move to an ozuku for the finisher. That would be quicker than the mikawa (thanks for the correction...) progression on just one base stone.

I've got a variety of tomo to work with. They are marked up by hardness, but that's not the end all be all of course.

I didn't write in there, but I do like honing on JNats a lot. There is much more sensory feedback... feel, smell, visual. The final edge is superior to me as well... An Ark by comparison is fairly dead.

SilverSwarfer: are you going to the Shapton after the JNats, or just using them as a comparison?

Originally Posted by HungeJ0e

I went back to my kiita today... It is faster than the other finishers (shobudanai and the ozukus), I'll see what edge I can max out on that. My plan right now is to shave off that, then test the tsushima black. As Steve56 suggests, I may be able to get a relatively quick progression of tsushima (with it's tomo), my kiita, then move to an ozuku for the finisher. That would be quicker than the mikawa (thanks for the correction...) progression on just one base stone.

I've got a variety of tomo to work with. They are marked up by hardness, but that's not the end all be all of course.

I didn't write in there, but I do like honing on JNats a lot. There is much more sensory feedback... feel, smell, visual. The final edge is superior to me as well... An Ark by comparison is fairly dead.

SilverSwarfer: are you going to the Shapton after the JNats, or just using them as a comparison?

Re: back and forth between JNATs and synths: it depends on the situation. I’m exclusively shaving off naturals now.

Since the JNATs camouflage scratches do well, I’m using the 30k to bring up polish and expose deeper scratches to provide a reference.

I also have been changing honing angles through progressions to identify which striations are given by which stones.

Staying organized in this way has really improved results for me. Also notes. I experiment way too much to remember what I did last week to which razor. Having a record has been a big help.

They are naturals and will vary, especially with technique, slurry honing is heavily technique dependent.

A good way to test a Jnat is to bevel set a razor on a 1k, you want a deep even stria pattern, make a thick-ish Diamond plate slurry and see how aggressive the base stone is, how the slurry breaks down, thin, and polish?

With slurry from natural stones and nagura more variables are in play. We are trying to quantify a moving target, dictating a formula. You will get a feel for different slurry viscosity and cutting/polishing ability with experimentation. Viscosity does not equal particle size, or quantity and can vary from stone to stone. They are natural, all labeled/stamped Asano are also not the same.

Different nagura will polish a stone face and make slurry differently with each stone and tomo. It is not just about the slurry, especially for finishing. This is the technique part, do not over think it, experiment.

Learn your stone without adding variables first. Look at your bevels and edges with magnification, as much as you have, at least 60-100. A USB is helpful here, (and cheap) to take photos for comparison, High magnification will tell you a lot when learning a stone.

Look at the fineness of the stria/kasumi pattern and more importantly the edge straightness. The goal is the edge, but the bevel pattern can tell you if you are gong in the right/finer direction.

Once you have a good baseline on your stone, add your nagura. With Nagura you are dealing with 2 sets of variables and how they interact and may be breaking down at different rates.

I rarely use a Mikawa progression, it is too slow, and do not see any benefit to the edge. I jump off a good polished 8k edge to a Tenjyou, and finish on a fine diamond slurry or hard Tomo, I have several Tomo that work well with different base stones.

For touch up, I normally start with a Tenjyou, refine the edge then finish as above. You can easily and quickly go from a 1k edge, to a nice heavy kasumi bevel with a Black Tsushima nagura slurry, they are aggressive and break down quickly, you may have to refresh the slurry, then Tenjyou and finish.

A 2-k bevel setter is even faster and for most edges is more than enough to set a bevel quickly. I use the Naniwia Green Brick 2k knife stone.

Diamond slurry and/ or Tomo assortment, opens a host of variables, but can deliver some great edges. Experiment to find a combination that works for you with what you have.

Do not obsess with water finish, few stones will finish on plane water, what matters is the edge not how it was finished.

The bottom line is that Jnat base stones and Nagura are natural and will each perform differently, so experiment to find which stones work well together for your current technique. You can make it as complicated or as simple as you wish. All that matters is the edge.

Silver, if you are getting random deep stria at your finish, you are not spending enough time on each stone to remove the previous stria.

Probably one of the most important stones in any progression is the mid grit stone,3-5k. This is the stone that removes all the deep bevel setting stria. Spend some extra time on your 4k, and re-lap your stone before your final finishing strokes to get as pristine an edge as possible.

Your 8k Snow White should leave a near mirror finish on the bevel and a super straight edge. If it is not, try grid marking and lapping. From the 8k you should be able to go straight to finishing nagura.

While stria/kazumi pattern can point you in the right direction, focus on the straightness of the edge. I use the Tenjyou nagura to remove any remaining synthetic stria, establish a kazumi pattern and refine the edge. From there a base stone diamond slurry or tomo to finish.

Diamond slurry will break down rather quickly, depending on the stone. So, diamond plate grit size does not matter all that much. That is one of the goals of Diamond slurry, to break down the slurry to its finest particle size while polishing the bevel and straightening the edge.

At each stone or nagura, the edge should continue to get straighter. At this level, stropping between stones or nagura can really make a difference.

Keep experimenting, moving towards simplifying your process, it will make your edges more repeatable.

Shaved with my kiita edge... it was very good. Not sure it was good as the ozuku edge on keeness. Somewhere north of an 8K edge maybe on par with a 12K for keenness, but almost velvety soft. It's nice to start to understand the range I can play with.

I then took that edge back to my 8K to "buff out" the haze and get back to a mirror, and went to work on my tsushima black.

Turns out I don't have a tsushima black, but a very hard variant of the tsushima blue that is still being sold on Amazon (the stone itself is black). I didn't do much with it when I first got it, for a couple reasons, but mainly because I was just moving out of synthetics and into naturals. I didn't even properly lap it...

It's freakin' hard. Not trans ark hard, but harder than my ozukus, shobu, and certainly the kiita. With an Atoma 400 it was slow going... and I may now need a new 400 pad. It's a nice sized bench stone. I've seen some speculation that these aren't natural stones but some sort of reconstituted material... while the stone was very uniform I do think it's a mined stone. It also does have small "sparkles" in it (not evidence for anything, just an observation). When I finally got it flat (and even then the corners weren't there, but the working surface was good), I rubbed with the tomo nagura to build slurry, and then worked my 8K edge for a good 60 laps. Enough to ensure I got slurry breakdown (if indeed this stone has friable slurry). Not a ton of haze, some but markedly less than the kiita. The slurry smelled of iron though by the end, so there's that indicator. I don't know if it's finer than the kiita, or its slow, or what.

The shave this morning was also a good shave. The tsushima certainly didn't dull the edge. It was an improvement over a standard 8K edge, so there's that. Still... I don't know where this stone lies. I think I'll take the edge back to a 1K, work a botan and tenjyou on the tsushima, and then finish with the tsushima tomo. Hoping to get an idea of how fast it is and how well it falls into the lanes of finisher/mid-range etc.

Sticking with one razor for all of this to work the baseline... it's a bit of a beater, but excellent steel... mid-century Rauh cutlery square-point made in Germany for an American importer. Blackened tang, no jimps, was my first straight and while nothing fancy (although it has nice bone scales) will take a great edge and give an excellent shave. Not worth much but sentiment. There are many like it, but this one is mine.

I always go from a 1k to a full progression.

From reading this thread so far i could agree or disagree with a lot of it... I can only assume that these stones work differently for different people..

I was just reading online threads from 2010 regarding slurries and what i found interesting was the lack of knowledge. It seemed like a few ppl had read a few things but nothing like today.

So many guys with so many stones and experience .... We have evolved as a race