Thread: Jnat questions

I am fairly new to jnats and have a few questions or thoughts I figured I might enjoy feedback for.

I read that most jnats have very similar particles sizes?
Is this true? Are harder stones finer or have smaller particles or flakes generally speaking?
Softer less compressed stones particles size vs hard highly compressed stones particle size?
Or is it more about softness / hardness and how easily slurry is released that determines the fineness or coarseness of the stone?

When the slurry get worked, it breaks down and gives finer results?
On softer stones fresh slurry is released by the stone itself, but on harder stones they don’t self slurry easily or at all? So you can refine the slurry without other interference for very fine results?

I also read about hard stones scratching the blade, is it problematic to hone on water only on very hard jnats?

I’ve read so many different things on various forums I’m not sure how to deal with everything. I know it will be a trial and error thing.

I was told to be careful with naguras not to scratch the base stone, but then after the naguras they speak of using a diamond plate to make tomo slurry. Wouldnt the diamonds also leave some sort of scratches, or is that a non issue?

Does it make sense to use a softer tomo like 4 - 4,5 hardness to make slurry on a 5 awasedo and work that slurry from the softer tomo until it gets finer?
Would the slurry from a 4 or 4,5 break down easier than a 5?
Or do they both break down the same way, or is a 5 finer to begin with?

Because i have a few harder stones mid 5 or so, when using a diamond nagura i can feel some scratchy particles get released and microchip my blade, atoma 1200.
Has this happened to someone, i have it happen on a few stones, not all?

I was thinking about experimenting next time with a harder lvl 5 basestone awasedo, go thourgh a full nagura progression and finish by using the diamond plate on another stone maybe a 4,5 hard one and transfer slurry from diamond plate to my lvl 5 basestone, so I dont scratch the base stone and I have a bit softer slurry to hone with?

I'm just now playing with two , I have myself. So not much help from me, though interested in some of the same questions you have.

One seems suited to knives, and a fast cutter with slurry created with a worn DMT.
( I have no Nagura's ). Just using them for finishing hones. I like knowing what a hone is capable of at this stage, by itself with water only, and dry.

I've found that dry honing brings the best results, for me, with one of the two hones I have. Having a good base hone seems to be the goal, with J- Nats. Nagura's are your progression to the base hone, in my understanding of them.

I'll say this, though. I am impressed with the two I have, and the edges they provide.
So far, the best came from several passes on a dry hone with the weight of the blade.

The swarf will slow the ability of the hone from cutting, and do more of a burnishing effect.

Wished I had more to add, so here we sit, together.

Originally Posted by TristanLudloz1928273

I am fairly new to jnats and have a few questions or thoughts I figured I might enjoy feedback for.

I read that most jnats have very similar particles sizes?
Is this true? Are harder stones finer or have smaller particles or flakes generally speaking?
Softer less compressed stones particles size vs hard highly compressed stones particle size?
Or is it more about softness / hardness and how easily slurry is released that determines the fineness or coarseness of the stone?

When the slurry get worked, it breaks down and gives finer results?
On softer stones fresh slurry is released by the stone itself, but on harder stones they don’t self slurry easily or at all? So you can refine the slurry without other interference for very fine results?

I also read about hard stones scratching the blade, is it problematic to hone on water only on very hard jnats?

I’ve read so many different things on various forums I’m not sure how to deal with everything. I know it will be a trial and error thing.

I was told to be careful with naguras not to scratch the base stone, but then after the naguras they speak of using a diamond plate to make tomo slurry. Wouldnt the diamonds also leave some sort of scratches, or is that a non issue?

Does it make sense to use a softer tomo like 4 - 4,5 hardness to make slurry on a 5 awasedo and work that slurry from the softer tomo until it gets finer?
Would the slurry from a 4 or 4,5 break down easier than a 5?
Or do they both break down the same way, or is a 5 finer to begin with?

Because i have a few harder stones mid 5 or so, when using a diamond nagura i can feel some scratchy particles get released and microchip my blade, atoma 1200.
Has this happened to someone, i have it happen on a few stones, not all?

I was thinking about experimenting next time with a harder lvl 5 basestone awasedo, go thourgh a full nagura progression and finish by using the diamond plate on another stone maybe a 4,5 hard one and transfer slurry from diamond plate to my lvl 5 basestone, so I dont scratch the base stone and I have a bit softer slurry to hone with?

That's a lot of questions!! lol
I am no expert on them but do you use them. Perhaps Steve56 will chime in when he sees this as he is very knowledgeable in this field.
Do all Jnats have the same size particles? I don't have a SEM so have no idea but I would think that is a very broad statement and most likely not true at all.

Hard stones do not release any slurry,no. Softer stones can self slurry, yes of course.
In my opinion a very hard Jnat is best used with a little slurry to temper the edge. When used with water only it creates too sharp/unfriendly edge.
Conversely a softer stone is generally easily used with water only. You can have a particle release and scratch with any nagura either from a contamination from the nagura or even base stone. Best practice is to round the leading edges of nagura to prevent chipping and larger pieces breaking off. Never use a heavy pressure when making slurry!!
I have an extremely hard Jnat with a perfectly matched tomo that is quite hard as well. It takes quite a lot of time to make a light slurry compared to any other combo. With this particular combo a light slurry is used from 8k to establish a nice hazy fine edge then thinned with water over a few sets till the edge is just beginning to glow a bit and haze is disappearing about 50-60%. This creates a nice face friendly yet keen edge to me. Experiment

Regardless of how the stone was labeled hardness wise I would always check with water only and see what it produces. Many can bring you from 8k to finish with water only unless they are very hard. Experiment.

Nagura can scratch the base stone and deep scratches on any finish stone is not wanted so there is that.
Hard vs softer nagura? You will have to experiment. A general approach is with a softer nagura - but not always. The nagura you chose will dictate whether your slurry is mostly base stone (hard nagura) or mostly nagura (soft nagura) or somewhere in between.
Generally very hard stones are considered better finishers but not always. If a very hard base stone is dressed well (think barber hone) it will act finer and stay that way because it is so hard as opposed to a softer one.
This may not have anything to do with grit but rather the binder. What makes it so hard is a combination binder and grit so smoothing the base stone limits or flattens out any irregularity in binder and grit together to avoid any unnecessary scratching.
It has been shown that the slurry does not really break down rather the binder does. Like near any other stone more slurry= more coarse, regardless what type of slurry is used.

When people talk of diamond plate being used it is generally a very worn one and scratching is a non issue. Many will test the base stone on its own merits of slurrying it and working their way to water only to see what it is capable of. Its not really the whole story though IMO. It can just serve as a carrier to nagura that adds just a little of itself as well . Experimenting is a must.

If a full nagura progression is wanted there is no point going much past a bevel set before beginning. Going to a high level synth to an atoma made slurry is pointless as well IMO.
For me, if a nagura is used it will only ever be a Tomo after 8k for speed and best use of everything I have. Doing things this way take a lot out of the equation. Quality of each nagura specifically. Start with a decent edge and go from there.

Hope that helps some. This is just my take on things. Experiment.

Found this thread at Badger and Blade. Seems related to what’s going on here.

https://www.badgerandblade.com/forum...honing.615288/

I have an oozuku and a cube shaped kuro nagura. I occasionally use it to finish an edge after a coticule progression, but really haven’t used it since I got my Vermio and my la Lune.

I have never done a full Jnat progression, so can’t comment on bevel setting or intermediate honing steps, but it does seem to be a reasonable finisher.

Take a look at this site as well. The author seems to be adding to it in increments.

https://naturalwhetstones.com/natura...-stones-jnats/

I have zero experience with Japanese stones of any kind so I have no real input but I am watching the answers because I am intrigued by them. Honestly, I have intentionally steered away from them up to now because of the investment heavy nature I have heard they possess. That and the fact that I am already fairly heavily invested in Arks spawned by the inheritance of a number of them.
This is actually one thing that intrigues me about jnats. They are diametrically opposed to Arks in their nature. To me this is neither good nor bad but mainly different. You're not slurrying an Ark. It will slurry whatever you use to try and slurry it. Because of this they are very predictable, like hard science/strict math predictable. Lubes make a slight difference but mainly only in speed.
I think of the difference this way: using jnats seem to me like cooking a fine meal where skill is key but ingredients play an equal or greater part, the skill is in the working of the ingredients. Using Arks is like fine tuning a hotrod. The parts are what the parts are and that will never change. The skill comes in manipulating the parts to perform at their maximum potential.
I think I would enjoy jnats if I ever made the plunge but.it.seems (and correct me if I'm wrong) to be a completely different sport.

Novaculite is a type of stone.

Jnats are a form of sediment that have been pushed over the years from the bottom of the ocean to the op of a mountain.

Two competely different things.

Generally you want a harder stone especially if using nagura progression. I avoid diamond plate slurry as I have always gotten better results with a tomo. Do know though that a tomo will not increase how sharp your base stone will get your final edge. Your tomo can be harder or softer - usually but not always the harder ones are finer but harder to raise a slurry with. It is great when you have a soft one that is very fine as they build slurry easier in most cases. Slurry does break down and become finer - thing of it like a corn chip that slowly loses its rigid edges with use.

What I like to do is first test your base stone to determine what edge you can get from it (this scenario also will test your tomo). Take your edge to a 8-12k synthetic edge then just do a tomo slurry to water. Can repeat this test with different tomos to see which you like more. Can do multiple tomo sessions if you think your tomo was not quick enough. Once you get a good edge doing that, you can start experimenting with using additional naguras as a progression.

Water only on hard stones is okay, but can mess up an edge if your razor is jumping around on the stone because it feels like it is sticking to the stone (small amount of slurry will reduce this and make finishing easier). Also not all slurry will break down to the same fineness. Can think about slurry being corn flakes that lose rigid edges and get finer, however a big flake will not be as small as a small flake when fully broken down.