# Thinking about bying the JNS Red Aoto.



## PalmRoyale (Sep 25, 2016)

Through my work I have some experience with soft stones that develop a lot of mud during sharpening (mostly King stones and the large green Naniwa) and there's something to this way of sharpening that I really like. I suppose you could say I like playing in the mud :lol2: I've seen the video on the JNS Red Aoto and it's also a very muddy stone but I'm not sure about the 2 different grits. Does this stone give you a 3000 grit average finish and how easily does the grit break down to give a more polishing action? Also, how does this stone perform on high alloy and powder metal steels?


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## PalmRoyale (Sep 25, 2016)

No one here with experience with the red synthetic aoto?


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## DamageInc (Sep 25, 2016)

It performs very nicely and leaves a cool hazy kasumi finish. Feels to me like something around a 4k finish.

Though it is sold as a splash-and-go, mine has started sucking water and for the past six months I've left it as a permasoaker. It is a soft stone, and you need to flatten it often.


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## XooMG (Sep 25, 2016)

Weekends can mean limited activity. Please be patient.

I do not have strong opinions about my red synths (plural because it broke in half pretty suddenly). I think it is a reasonably nice stone that muds up quickly. It seems rather aggressive so the surface loads up while polishing, which can cause some streaky unevenness. I do not sharpen with muddy stones really so don't have much opinion.

As for grit level...I don't know. It seems like 2k and 4k mixed, which to me is not much like a dedicated 3k, but stones have different compositions and "grit" is not always consistently comparable. I would put the finish around 2k, comparing with other media.

Grit breakdown is not a feature, but it seems to be widely misunderstood in the naturals game too.


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## Krassi (Sep 25, 2016)

Hi!

Its a good Stone.. Muddy, splash and go and i dondt use it any more because i got a khao men tnat 
but still good stone


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## PalmRoyale (Sep 25, 2016)

DamageInc said:


> It performs very nicely and leaves a cool hazy kasumi finish. Feels to me like something around a 4k finish.
> 
> Though it is sold as a splash-and-go, mine has started sucking water and for the past six months I've left it as a permasoaker. It is a soft stone, and you need to flatten it often.



I don't mind that it's a soft stone, it's actually why I'm interested in it. Working with expensive Coticules taught me how to use a stone to keep dishing to a minimum. My La Dressante at work sees a lot of use and I've flattened it only once the past 6 months. I can also keep a King Deluxe 1200 flat for a long time. I'm confident I can keep the aoto flat as well. The main reason why I'm interested in this stone is because it seems like a good stone for a quick touch up of my chisels without the need to go to a higher grit stone every time.


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## psfred (Sep 25, 2016)

I don't think an aoto is a good stone for chisels, too soft. You need a dead flat very hard stone to maintain a flat bevel on chisels in my experience (ditto for plane blades).

A Bester 1200 will do a much better job, followed by a 6K grit of some sort and stropping on chromium oxide on a hard surface. It may work OK if you use Japanese hard carbon steel chisels, but typically it's not a "touchup" stone for hard steel, leaves a very so-so edge that requires polishing on a higher grit stone to cut well. 

Peter


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## PalmRoyale (Sep 25, 2016)

Don't get my started on the importance of flat chisels. I've been working as a shipwright for the past 17 years and I can tell you it's not as important as people think. It's even less important for a hand plane. In fact, I will say that if you need a chisel with a perfectly flat back and bevel to deliver your best work, you just don't know what you're doing.

But it's good to know you think it leaves a "so-so" edge. That's something to think about.


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## Steampunk (Sep 25, 2016)

The JNS Red Aoto is one of my favorite stones for knives, and there is the possibility that it might be a good stone for you, but for my own tastes I don't care for it so much on woodworking tools...

Firstly, it is advertised as splash & go, but in terms of long-term stability and performance I find it best - as with most resinoid 'splash & go stones' to perma-soak. This solves a great many of the issues mentioned above, and amplifies the stone's lovely creamy feel. It's an awesome stone for kasumi finishing on warikomi or san-mai knives (Probably the best synthetic I've used for this application once perma-soaked.), I really like the edge on 62hrc+ steels (Particularly carbon) for food prep or other applications where you need an edge that is toothy yet still somewhat refined, and as mentioned before the tactile feel is pretty sublime for a synth. It will also tackle more wear-resistant PM steels, although not as well as some of my stones.

However, for touch-up applications on chisels or plane irons, the cutting characteristics of this stone don't suit my personal tastes. The noteworthy softness of this stone (Softer than any of my Coti's, including my rather chalky and easily gouged La Gris!) requires a light touch to prevent over-convexing or slurry-dulling the edge, which means you can't lean into it much when asking a fine stone to do the job of a medium one when re-setting a mildly blunted edge, and my own free-hand angle control isn't good enough to touch-up micro-bevels on a stone this soft without edge-trailing only strokes, or risking gouging the stone/blunting the edge. I haven't seen many sharpeners, especially those in a hurry, who would have good enough control. 

In terms of the edge quality, it's not as good as a dedicated 4-6K stone for push-cutting applications since the primary scratch pattern is only 2K with some 4K scratches thrown in to give it some polish. However, for the application the stone is primarily used for (Wide-bevel or single-bevel Japanese knives.) it's really quite nice, in my opinion.

I know that it isn't super-soft as you have grown to like, but a stone - also from the JNS range - that I think may be good for this application is the JNS 'Speckled' Aoto Matukusuyama: http://www.japanesenaturalstones.com/jns-aoto-matukusuyama/. This is the harder, more refined brother of the JNS Red Aoto, and it's a superb touch-up stone. It has a finer scratch-pattern that is more adept at push cutting rather than slicing (I believe it's a 3+5K blend), it cuts faster than a 6K finisher (Even my Gesshin 6K S&G, which is pretty fast for its grit level; especially for touch-ups.), and the density of the stone allows you to use more pressure for touch-ups or sharpen micro-bevels without risk of excessive convexity/slurry dulling/stone gouging. The feel is pretty creamy for a firmer stone with good feedback, and it can still build mud, but it depends upon the application (You need some soft steel/iron cladding in contact with the stone for that to happen in any major way; you may manage it if you're sharpening Japanese chisels/plane irons.). 

Building a thick paste slurry on your Coti's will easily allow them to grind in the 2K ish range for touch-ups, but this does result in some slurry-dulling that needs to be refined with dilutions, so it isn't as quick a process as a synthetic stone.

Another option for touch-ups providing the edge isn't too severely dulled, and since you are working with PM steels, is the Gesshin 6K Splash & Go I mentioned: https://www.japaneseknifeimports.com/collections/shiage-toishi-fine-stones/products/gesshin-6000-splash-and-go-stone. This is a really interesting stone... It's the best synthetic finisher I have for wear resistant steels (Including stuff like HAP40 and ZDP-189 @ 64-65hrc.), and the slightly forgiving medium density of the stone allows it to cut faster and more effectively than its grit rating would suggest, as with pressure it introduces some slight but not excessive convexity that applies more force to the very apex almost as a strop would. You can actually see it when observing the edge under a microscope, as the scratches curve very slightly with the apex being more polished than the rest of the edge bevel (Similarly to a pasted strop. It isn't faceting, however, like one might see on a harder stone with an angle change.), and you can make rather large grit jumps with this stone (10X isn't problematic, and with this stone feels like a 3X jump might on a different 6K.). However, it is still just firm enough to do edge leading passes, and micro-bevels with pressure. I use this to touch-up my PM kitchen and pocket knives when they stop shaving hair, and only have to drop lower if there is damage or serious wear, due to the sharpening characteristic mentioned above. It's a pretty smooth feeling stone, and can build mud, but as above only really in the presence of soft cladding.

Another option may be the Gesshin 4K vitrified soaking stone, which is supposed to be a very fast cutter for its grit level, or Dave Martell's favorite Imanishi Tamago 4K touch-up stone that sounds like it works similarly to the G6K S&G, but I haven't tried either of these stones.

Hopefully this helps...

- Steampunk

P.S. For what it is worth, whilst absolute flatness can be overrated in work for woodworking tools, I do find it useful when it comes to sharpening. Having a flat, precise tool makes it easier for me to get a consistent edge each time, as I am following an established geometry rather than trying to sharpen with stone dishing or convexity from mud or natural wobbling that varies from sharpening to sharpening and changes the edge geometry each time. Also, I find it somewhat easier to minimize stone dishing with woodworking tools than with knives, as - due to the shape of the tool - one can use close to 100% of the stone and the force is spread over a wider area than with a curved knife blade.


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## PalmRoyale (Sep 25, 2016)

Okay, so the JNS Red Aoto is out of the question. I did think about getting the Gesshin 6000 splash and go but I didn't take I have to pay VAT and import duties into consideration at first (US to EU). If customs picks it out it's going to be an expensive stone. In the mean time I've ordered the Sigma Select II 6000 which from what I understand is actually one of the best stones in the Sigma line up. According to Lars it also shares the same crazy fast cutting action of the Select II 1200.

Btw, I've only began seriously using synthetic stones for personal use a short while ago. Before I got my PM-V11 chisels and plane blades the only thing I've ever needed were my Coticules. I have used synthetic stones here and there and I know what I like in terms of hardness and feedback but I still have a lot to learn. It's also different when you buy a stone for yourself compared to using whatever stone is available where you work at the moment. But learning is something I'm willing to do because I love PM-V11 steel so much.


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## Steampunk (Sep 25, 2016)

PalmRoyale said:


> Okay, so the JNS Red Aoto is out of the question. I did think about getting the Gesshin 6000 splash and go but I didn't take I have to pay VAT and import duties into consideration at first (US to EU). If customs picks it out it's going to be an expensive stone. In the mean time I've ordered the Sigma Select II 6000 which from what I understand is actually one of the best stones in the Sigma line up. According to Lars it also shares the same crazy fast cutting action of the Select II 1200.
> 
> Btw, I've only began seriously using synthetic stones for personal use a short while ago. Before I got my PM-V11 chisels and plane blades the only thing I've ever needed were my Coticules. I have used synthetic stones here and there and I know what I like in terms of hardness and feedback but I still have a lot to learn. It's also different when you buy a stone for yourself compared to using whatever stone is available where you work at the moment. But learning is something I'm willing to do because I love PM-V11 steel so much.



I wish you well with the Sigma!  This is a stone line I have never used, but I may need to try it some day...

I have never sharpened Veritas PM-V11, but I have actually been impressed with how well my Coti's and BBW's deal with the PM cutlery steels I sharpen (SRS-15, ZDP-189, HAP-40/CPM-M4, S30V, etc.); I can actually jump from a Naniwa Pro/Chosera 800 to my La Verte or La Veinette on a thin-yogurt slurry through a dilucot progression to clear water without too much issue. Have you ever found a metallurgical breakdown of PM-V11's constituent alloys? I haven't been able to find one, so I don't know if it's any more wear resistant than the steels I've sharpened. :scratchhead: Do you build a slurry with another small bout, or do you just rely on auto-slurry? 

- Steampunk


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## PalmRoyale (Sep 26, 2016)

Nobody knows what PM-V11 is made of because it's a closely guarded secret. What I can tell is that it's a a very nice steel. It's far more wear resistant than A2, even at a low angle like 25 degrees. It's also a bit easier to sharpen that A2 but for some reason it just doesn't get along with a Coticule ( just like A2 and the reason I now have a Sigma 1200 and the Sigma 6000 on the way). I have to build up a lot of slurry for decent steel removal but as you know sharpening with a lot of slurry also dulls the edge. It also hardly produces any sparks when I take it to a bench grinder.


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## Mucho Bocho (Sep 26, 2016)

PalmRoyale said:


> Don't get my started on the importance of flat chisels. I've been working as a shipwright for the past 17 years and I can tell you it's not as important as people think. It's even less important for a hand plane. In fact, I will say that if you need a chisel with a perfectly flat back and bevel to deliver your best work, you just don't know what you're doing.
> 
> But it's good to know you think it leaves a "so-so" edge. That's something to think about.



Kind of a dickish response to Peter. Especially from a new guy asking for help. Petter has given me sage advise in the past. You're on notice Palm


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## PalmRoyale (Sep 26, 2016)

Mucho Bocho said:


> Kind of a dickish response


Yeah, I get that a lot on forums :biggrin:


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