The Aoto Thread

[holli4pirating]

Maybe it's just me, but it seems there has been a lot of talk about Japanese naturals recently. One that seems to come up a lot is the Aoto. Off the top of my head, I seem to recall hearing that it cuts like a 1k with slurry (and is rather soft, so slurry is formed rather easily) but can polish more like a 4-5k with just water. As such, it seems like the Aoto may be a low grit natural that members may be interested in.

I thought I would open up a thread for discussion of the Aoto, and I would be particularly interested to hear what those who have used this stone have to say about it. The more information you can provide, the better. (What razors (grind and country of origin), slurry vs no slurry, cutting speed, softness, final polish, number of strokes, previous hone in progression, next hone in progression, shave off it, etc.)

Thanks in advance.

Oh, I should mention that I do have one on it's way to me, and I'll be chiming in with test results as soon as I can.

[Pyment]

Haven't gotten my Aoto yet. (still trying to work a deal for some other stones to "keep it company" on the trip).

with Aotos being in the 1000 to 3000 range, I am thinking there won't be much before.

I did get the following email from a seller of Aotos:

Some of the stones, are not the same quality as they used to be, the Aoto is one of these stones. It has been overharvested, and so many of the pieces show broken corners, and cracks.

I wonder what the stone I will be getting will be like.

From there I hope to go to a Ohira stone - not Suita but from a shallower layer (Tomae?). From the description it sounds like a medium finishing stone.

[hi_bud_gl]

waste of money it is not mean to for straight razor's.

[Pyment]

The Aoto? or the Ohira?

And why? I paid little for these, less than 1/2 of what I paid for my coticule.

The hope is that I can set bevels and remove chips in place of my DMT and leave scratches that are not as deep. Most Aoto come from Kouzaki:

from Japan Tool:

Kouzaki is situated in the west side of Kyoto. It was famous for its med grit stones called Aoto (Blue stone). Kouzaki Aoto is considered to be the best Aoto, but they are almost impossible to find nowadays. Recently Kouzaki's Suita is starting to receive it's popularity long after this quarry was closed. It suit modern hard steel with the stronger cutting strenght. Suita has the strongest cutting strength of all stratum.

These stones are for Nakato sharpening where you can use either natural or synthetic stones (in the 1000-4000 range). The claim is that the natural stone will leave less deep and softer scratching that will be easier to polish out with higher grade naturals. Boker sells a synthetic Nakato stone at 1000k Amazon.com: Nakato Sharpening Stone: Kitchen & Dining

The Japanese hone masters (can't really call them honemeisters) say this is where they go from sharpening to polishing. Coincidence that we have been talking about the 1000-4000 grit range with this very same idea?

another quote from Japan Tool:

Aoto is a natural medium stone you use between #2000 synthetic and #6000/8000 synthetic or natural medium finishing stone. It is possible to jump to #8000 from #2000, but it takes long time to erase the marks from #2000, and also you'd lose a lot of #8000 by fixing the flat of the surface.
Although synthetic finishing stones are fast in cutting thus very convenient for daily use, the marks that's incised are quite deep even with #8000, it takes lots of time to erase it with the finishing stone. So when I want to make the edge extra fine, I would switch to natural stones altogether after #2000, and use Aoto > natural medium finishing stone > natural finishing stone.

This is where Narutaki fits as other Aoto from Kouzaki, Inokura, Miyagawa, and others. Kousaki is just the most famous.

330mate says that these softer stones are used in the first step in the final stage of sharpening and come from:

The mine list which produces a lot
Takashimamyoukakusan ,Ohira ,Mizukihara ,Hakka ,Okunomon ,Yaginoshima ,Kouzaki ,
The stratum list which produces a lot
Shallow of Tomae ,Suita ,Namazu ,Softer Renge Suita,AKAPIN ,The stratum that touched air and water for many years ,

Akapin is the shallowest layer mentioned by So at Japan tool and, apparently, they can be found up to the shallower layers of Suita.

The next step up would be to the medium stones where we are moving from sharpening to polishing. (at least this is my interpretation).

Medium is suitable for...

1. To make most beautiful haze and mist.
2. Sharpness lasts for a long time if hardness of steel rise up to Hrc62.
3. Accept wide range user with sharpening skill.
4. Top class sword finisher which production is very very few.And very expensive.
5. 2nd step final stage sharpening which is suitable for Japanese planes ,chisels ,razors.
6. Hi-class water quenching Japanese chef knives and blade tools.

This is where I see my Oohira stone fitting in. If It performs as expected.

.The mine list which produces a lot
Ohira ,Mizukihara ,Hakka ,Okunomon ,Yaginoshima ,Kouzaki ,Shobu ,Nakayama ,Okudo ,Narutakimukouda ,
The stratum which produces a lot
Suita ,Many kind of Tomae ,Fresh colored Tomae ,Much Tomae in mines which is located in North of Mt.Atago.

Finally we get to the hard stones (like most of us have discussed experimenting with) - Shoubu-dani and Nakayama stones are the only genuine Hon-yama stone, but many of the deeper suita can do the same things. We across the sea can't really handle the stones before buying and we are forced to decide our tolerance for risk.

This is not a effort for the faint of heart.

I am also hoping to get that refinement in grit by lapping a little, honing a little, then lapping some more in order to refine the chert.

Ultimately I don't know my Aoto's pedigree. But it is supposed to fill the gap between 2K and 8K. Properly lapped, it should be what I am looking for.

[DwarvenChef]

I have a piece of a synthetic aoto that was cut down for me. I'm putting a base on it so I don't worry about breaking it. It is soft feeling and will produce slurry with a knife blade. Not sure how it will react to razors. I have a few that are just started on 325 to set a bevel, bad edges had to go away... I'll post what I find when I'm done. Be a few days till I get the stone set...

[kevint]

I'm not sure there is such a thing as just water with most of these(the ones readily available) They are that soft/slurrying.

I have a hard time getting 3-5k feel sharp. It's like go and go and never seeming to get anywhere. I guess it just takes some getting used to; far softer than anything else I use.

If it is a waste of money at least it is not a lot. For those not ready to spend 2-4 hundred on a top notch naka-to; the grab bag aoto is the only choice that comes to mind.

I can take a plane iron and with some "heavy" pressure and just a slight lifting at the back to get up on the edge, both mine will produce an easily detected burr very very quickly. So they can definitely cut hard steel.

It's just exactly how to get the best from one on a straight I have not discovered in the 3-4 i have done on aoto.

[hardheart]

I don't guess I would call it a waste. I just took an old Torrey blade, did 20 laps on a Norton white ceramic (about the same as factory fresh Spyderco fine), looked at it at 100x, then followed with my aoto. I did 40 laps, took a look under the RS scope at 100x, and saw the hazy softening of the ceramic scratches. Did another 20 then 80 on clean leather and shaved. No prep, just a splash of hot water and some shave oil. Not a great shave, but my technique still sucks and of course my face wasn't ready.

To prevent slurry, I dipped the stone every 20 laps. It builds quickly with a knife, but not with the razor.

[Pyment]

Grab bag Aoto. fits.

For the price, it was worth a shot. Auctiva is just giving me fits as it won't let me pay for the item.

Once I get this payed for I hope to get that along with my grab bag unknown strata Ohira along with it.

I keep seeing advice not to use a lot of water on the Japanese naturals. I think the idea is to grind the grit/chert into smaller particles and improve the hone through use.

I don't know if it applies to the Aoto since I think these lower grit stones are actually soaked. I intend to not soak the stone but to use a small amount of water as I do with the higher grit stones. I make a big enough mess with honing slurry and such without going to a full soak. I only use one surface after all.

[kevint]

I call it that because i wouldn't feel right sending one back unless it was totally unusably flawed. The slight risk helps keep the price down. The less good one I use on knives, to clean synthetics, cut up for polishing slips, etc.

I don't soak, reasoning water coming in from all sides will be detrimental in the end. So it takes a minute or two to get it primed, and then enough to keep the consistency of slurry you like. With hard stones you wont use nearly as much because what soaks in is nearly insignificant.

These are quite different from kyoto stones like oohira et al. I think you can pick the best side or even use them all if you wanted.

[Pyment]

It will be much easier to decide what to do once I have it in hand. From some of the descriptions, it sounds like water will hasten its progress towards mud.