Coticules and Jnats

[Basil]

Howdy everyone. Up until now I have only been using coticules for all my straight razor needs. Last night I decided to order a jnat and some Nagura from jns.

Now my question is how different is working the slurry on a jnat compared to a coticule. Do I build the slurry and slowly dilute to plain water?

Also wondering if anyone has tried using a nagura on a coticule or coticule slurry on a jnat? Would the different slurries on the stones makes a difference?

 

[paintflinger]

Howdy everyone. Up until now I have only been using coticules for all my straight razor needs. Last night I decided to order a jnat and some Nagura from jns.

Now my question is how different is working the slurry on a jnat compared to a coticule. Do I build the slurry and slowly dilute to plain water?

Also wondering if anyone has tried using a nagura on a coticule or coticule slurry on a jnat? Would the different slurries on the stones makes a difference?

Different opinions, but if you want what I do, I do a bit of both. I fully break the slurry down, only adding water, if it is getting too dry. When I think it is fully refined, I dilute it slightly. I rarely go to water only on a jnat.

Keep in mind that the whole point behind diluting coticule slurry is that the garnets in a coticule don't break down. With jnats, the particles are breaking down to be finer and finer.

 

[kohalajohn]

Different people use different techniques. The biggest factor seems to be lightening the pressure as you go. You start with pressing hard, so half of the particle, to its full width, is pressed into the steel, making a deep scratch. You finish with light pressure so only the very top ten percent of the particle is pressing into the steel, making a shallow scratch.

And imho, using different cotis or different naguras may not be good, as you'll have large particles mixed in with small particles.

Some people simply use a worn atoma 1200 to raise slurry on their jnat and then hone with lightening pressure until you're finishing with only the weight of the blade.

Best of luck.

 

[musicman980]

I've done a koma nagura on a hard coticule, good results. Now coti slurry on a jnat is just crazy talk.

 

[SliceOfLife]

I have a full set of nagura, and they're just a collectors item for me at this point. Like Dilucot, a full nagura progression is a fun way to hone now and then, but the idea that it gives a superior edge on a razor is placebo if you ask me. Stone + Tomo after synthetics is the way to go for Jnat + razors in my book. If your Jnat is fast enough, you might not even need the Tomo.

 

[Namkcakram]

I have a full set of nagura, and they're just a collectors item for me at this point. Like Dilucot, a full nagura progression is a fun way to hone now and then, but the idea that it gives a superior edge on a razor is placebo if you ask me. Stone + Tomo after synthetics is the way to go for Jnat + razors in my book. If your Jnat is fast enough, you might not even need the Tomo.

Nailed it.

The biggest difference is coti cuts with garnets and garnets don’t break down because they are ludicrous hard. With light enough pressure they may either tumble and barely cut the steel, or just stay embedded in the stone barely removing steel allowing you to finish an edge finer than the ~3mu garnet size.

JNATs cut with silicates that are all manner of irregular shapes, but much closer in hardness and much more brittle than the steel edge itself. The slurry actually “breaks down” whatever that means, and alters it’s cutting behavior to finish finer than where it started. Coticules show a massive range of behaviors with varied pressure and slurry, JNATs you can keep consistent pressure and still watch a slurry progress in interesting ways.

Tomo slurry will generally start off finer than diamond generated slurry, but theoretically they would both end up at the same finishing point with the slurry “broken down/burnished/diluted” or whatever you want to describe it as.

Because of the differences there’s not much point in mixing JNATs and Coticules, and honestly the only mix that makes any sense is JNAT slurry on a hard coticule.

Like slice said a “full nagura progression” is a good way to hone, but be ready for a whole block of zen honing time to yourself. Faster to either run a strong cutting midrange and finish on JNAT/tomo, or to go synth to ~8k the. JNAT/tomo.

I love running a coti midrange to JNAT finish, but good luck convincing a Coti guy that a coti works best as a midrange stone.

 

[Basil]

Nailed it.

The biggest difference is coti cuts with garnets and garnets don’t break down because they are ludicrous hard. With light enough pressure they may either tumble and barely cut the steel, or just stay embedded in the stone barely removing steel allowing you to finish an edge finer than the ~3mu garnet size.

JNATs cut with silicates that are all manner of irregular shapes, but much closer in hardness and much more brittle than the steel edge itself. The slurry actually “breaks down” whatever that means, and alters it’s cutting behavior to finish finer than where it started. Coticules show a massive range of behaviors with varied pressure and slurry, JNATs you can keep consistent pressure and still watch a slurry progress in interesting ways.

Tomo slurry will generally start off finer than diamond generated slurry, but theoretically they would both end up at the same finishing point with the slurry “broken down/burnished/diluted” or whatever you want to describe it as.

Because of the differences there’s not much point in mixing JNATs and Coticules, and honestly the only mix that makes any sense is JNAT slurry on a hard coticule.

Like slice said a “full nagura progression” is a good way to hone, but be ready for a whole block of zen honing time to yourself. Faster to either run a strong cutting midrange and finish on JNAT/tomo, or to go synth to ~8k the. JNAT/tomo.

I love running a coti midrange to JNAT finish, but good luck convincing a Coti guy that a coti works best as a midrange stone.

I used to be a coti guy. Since using my jnat I know the coti limitations. So now instead of trying to sneak out the last bit of performance from the coti I’ll just go to the jnat and get a way better edge than I ever have before.

 

[Namkcakram]

I used to be a coti guy. Since using my jnat I know the coti limitations. So now instead of trying to sneak out the last bit of performance from the coti I’ll just go to the jnat and get a way better edge than I ever have before.

Amen.

I would still tell anyone to buy a Coti, because it’s so versatile and cuts through hard tempered steels like butter. It may be the very best natural midrange to pre-finish stone available. You can very much get a shaving edge off a coti as well, Just seems like a lot of people feel the need to take an edge a little bit keener.

 

[David]

I’ve shaved with edges off of just about every stone imaginable, including several of Docs Jnat edges which are incredible, but the right coti in the right hands tops them all from my experience. The really REALLY good ones are very hard to come by though, but if you can ever get your hands on one and really learn how to use it they’re hard to beat.

 

[Basil]

Amen.

I would still tell anyone to buy a Coti, because it’s so versatile and cuts through hard tempered steels like butter. It may be the very best natural midrange to pre-finish stone available. You can very much get a shaving edge off a coti as well, Just seems like a lot of people feel the need to take an edge a little bit keener.

I agree that they can do a lot. Also pretty simple. Make slurry, rub, add water do it all again, eventually you’ll get it right lol. I moved on to a jnat to do just that, wanted that little extra sharpness from my shaves.

I’ve shaved with edges off of just about every stone imaginable, including several of Docs Jnat edges which are incredible, but the right coti in the right hands tops them all from my experience. The really REALLY good ones are very hard to come by though, but if you can ever get your hands on one and really learn how to use it they’re hard to beat.

I’ve had a couple shaves from coti edges that were amazing. Now I get pretty close to those shaves with my cotis, but instead of trying tricks to get a little extra from them I’ll just hit the jnat. I also agree that the right coti could be amazing in the right persons hands. The only problem with that is I don’t have the time or the funds to experiment with a bunch of stones anymore.

I had quite a few cotis and I cut my collection down to three I thought were the best.

 

[SliceOfLife]

Imho the best coti edges aren't based on tricks, they're based on finding exceptional coticules. Many years ago, I was firmly in the "every coticule is a razor finisher" camp. Then I got my first non-finisher. It was a vintage stone 9x2.5 or so... and was CLEARLY meant for tools or something other than razors. It confused me because it went so against everything I believed and had heard from many experts. I've since had one other coticule that wasn't a razor finisher in my book... again, a very large vintage. I've also had several that I consider to be razor finishers, but only barely.

I've also found that many of the stones reach up into superior edges, far sharper than coticules are often believed capable of. I've got yellow coticules that finish finer than Les Latneuses, and comparably fine to my finisher Jnats. One special example of a coticule was a large (10x2") vintage (so don't assume that all large vintage coti's are tool stones, either), that I recently sold and within hours of it arriving received an email from the buyer raving about how it was the best coticule he'd ever used. I've got about a dozen coticules still hanging around and half of them are truly exceptional stones, that I'd put up against a Jnat without any qualms... but I bought 200, maybe more, coticules... usually specifically targeting stones that looked like these ones, to get maybe six of them. They're rare.

However, coticules that come quite close to a keenness available from Jnats, though a noticeable step down, but always with a coticule's exceptional comfort... are far more common. To the tune of 20-40% of what I've bought (focusing primarily on buying vintages that bear resemblance to stones I've used which demonstrated superior performance).

The truth is a good Jnat is always better than a mediocre coticule and a good coticule is always better than a mediocre Jnat. Beyond that, I wouldn't trust any claim that a coticule or jnat will always be superior, because it's going to probably be coming from someone with more experience with one type of stone and less with the other. Like I said, I've owned hundreds of coticules, and maybe two or three dozen Jnats. Now I filtered out the Jnats to where I feel I have two very exceptional razor finishers and one top shelf tomo, as well as a handful of other stones... but I can't say I've got the best possible Jnat finisher out there. Likewise, I wouldn't trust someone who's owned a couple dozen coticules to understand what the best coticules are capable of.

To put coticule variance in objective terms. I've seen coticules with 25-50mu garnets (the not razor quality ones). And I've seen coticules where the garnets are the size of or barely bigger than the abrasives in a Razor finishing Jnat (sub 1mu). Both are very rare examples, and the average seems to pull towards 3-8mu being typical for the largest garnet in a coticule slurry sample. Knowing how these "avg" coticules with abrasives the size of 4k synths perform, imagine the edges you get when you size those garnets down to what you see in a 16-30k synth. The edges get pretty mind-blowing.

 

[Namkcakram]

Imho the best coti edges aren't based on tricks, they're based on finding exceptional coticules. Many years ago, I was firmly in the "every coticule is a razor finisher" camp. Then I got my first non-finisher. It was a vintage stone 9x2.5 or so... and was CLEARLY meant for tools or something other than razors. It confused me because it went so against everything I believed and had heard from many experts. I've since had one other coticule that wasn't a razor finisher in my book... again, a very large vintage. I've also had several that I consider to be razor finishers, but only barely.

I've also found that many of the stones reach up into superior edges, far sharper than coticules are often believed capable of. I've got yellow coticules that finish finer than Les Latneuses, and comparably fine to my finisher Jnats. One special example of a coticule was a large (10x2") vintage (so don't assume that all large vintage coti's are tool stones, either), that I recently sold and within hours of it arriving received an email from the buyer raving about how it was the best coticule he'd ever used. I've got about a dozen coticules still hanging around and half of them are truly exceptional stones, that I'd put up against a Jnat without any qualms... but I bought 200, maybe more, coticules... usually specifically targeting stones that looked like these ones, to get maybe six of them. They're rare.

However, coticules that come quite close to a keenness available from Jnats, though a noticeable step down, but always with a coticule's exceptional comfort... are far more common. To the tune of 20-40% of what I've bought (focusing primarily on buying vintages that bear resemblance to stones I've used which demonstrated superior performance).

The truth is a good Jnat is always better than a mediocre coticule and a good coticule is always better than a mediocre Jnat. Beyond that, I wouldn't trust any claim that a coticule or jnat will always be superior, because it's going to probably be coming from someone with more experience with one type of stone and less with the other. Like I said, I've owned hundreds of coticules, and maybe two or three dozen Jnats. Now I filtered out the Jnats to where I feel I have two very exceptional razor finishers and one top shelf tomo, as well as a handful of other stones... but I can't say I've got the best possible Jnat finisher out there. Likewise, I wouldn't trust someone who's owned a couple dozen coticules to understand what the best coticules are capable of.

To put coticule variance in objective terms. I've seen coticules with 25-50mu garnets (the not razor quality ones). And I've seen coticules where the garnets are the size of or barely bigger than the abrasives in a Razor finishing Jnat (sub 1mu). Both are very rare examples, and the average seems to pull towards 3-8mu being typical for the largest garnet in a coticule slurry sample. Knowing how these "avg" coticules with abrasives the size of 4k synths perform, imagine the edges you get when you size those garnets down to what you see in a 16-30k synth. The edges get pretty mind-blowing.

Spot on for sure.

I’ve gone thru unlabeled vintages of both (definitely way more JNATs) and all I’ve learned is if you want to get down to honing you should just contact a trusted source and get one. Coticules have a huge advantage there in that they’re still mined and the bros in Ardennes seem to know what stones are good for and what have limitations. Obviously we’ve got a well known seller in Florida for modern select Coticules and he’ll filter out any nonsense tool stones.

JNATs unfortunately the only way to get a real bargain is buying used from a trusted source. Someone on the BTS threads can sell you a used one with little to zero fluff in the price. My best stone is a hideous used something asagi (claimed Yaginoshima asagi, but definitely outside the common hardness range). Anyways picked it up used for nothing from a trusted seller because there was no interest from buyers for a stone that’s so odd... not pretty, surface area looks like a handheld stone but WAY too thick to hold for that long. Seller swore it was his favorite stone for his first 3 years honing professionally, and I believe it now.