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Blue Aoto

Posted: Wed Oct 14, 2015 6:43 pm
by djwong
Since Brian had a question about my blue aoto, I thought I would post some pictures of the finish it can achieve. I purchased this stone about 4 years ago from a online knife retailer. The stone was marked as a "reserve" stone, as opposed to the regular aoto stones.

The stone is dark and smooth. Here it is all cleaned up for its closeup...
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I had a Kunikei blue steel chisel that I needed to sharpen. I took it from 500#, 800#, 1000#, to the aoto. Normally, I would go from 800# to 2000#, but I had the sigma handy. On the aoto, I raised a slurry with a 400# atoma. After a couple of minutes on the aoto, here are the results...
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This chisel could cut through a sheet of paper by pushing straight on the edge. It was a more than acceptable edge to work with. I would describe the finish as a cloudy mirror finish.

I next worked the chisel on my shiro suita. You can see the mirror finish is still cloudy, but a bit clearer.

I'll have to jig up a consistent way of photographing the edges of blades for better comparisons.
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Re: Blue Aoto

Posted: Wed Oct 14, 2015 9:33 pm
by Chris Hall
Pictures did not load...

Re: Blue Aoto

Posted: Thu Oct 15, 2015 12:08 am
by djwong
Sorry about that. Hopefully I fixed the problem. I host my shared photos on Google, on what use to be Picasa. Google has been changing things; first for Google+, now for Google Photo. Makes sharing individual images a bit trickier.

Re: Blue Aoto

Posted: Thu Oct 15, 2015 7:24 am
by Chris Hall
yep, all good now. I wasn't aware of that change to Google/Picasa. It can be hard keeping up with the shifting sands of the interweb..

Re: Blue Aoto

Posted: Thu Oct 15, 2015 8:52 am
by Brian
Nice work, that is incredibly flat. Can you take it from there right to the finish stone?

Re: Blue Aoto

Posted: Thu Oct 15, 2015 9:36 am
by djwong
Brian wrote:Nice work, that is incredibly flat. Can you take it from there right to the finish stone?
The shiro suita is my usual finish stone. I have not tried to go directly to my Nakayama Asagi. I'll try it when I sharpen the chisel again. The flatness is easy to achieve with this chisel. It is a chu-tataki chisel, so there is quite a bit more area for registration of the bevel on the stone. I also misspoke about the steel. I forgot that this chisel is blue steel. Edited my first post to correct the mistake.

Re: Blue Aoto

Posted: Thu Oct 15, 2015 6:16 pm
by Brian
Awesome, if you have a particularly aggressive asagi it might be fine. Do you change direction when you are polishing? That is my one regret of using a jig, it's hard to tell if you have removed all of the scratches because you can only go one direction.

Re: Blue Aoto

Posted: Sun Oct 18, 2015 5:59 pm
by Gadge
Brian,

Do you always use a jig? For anyway who does, please read on.

When I first bought bikes for my kids, of course I bought the ones with trainer wheels. Anyone who's done the same will know that when you consider the kid is old enough to cope without them, they don't agree and are terrified they can't ride without them. The problem is that the kids get good at riding with the trainer wheels and when you taken them off, they go back to being useless again. The kid winds up using the trainer wheels way longer than necessary. After going through all that, I saw that other kids started out with those bikes which don't have peddles, often with plywood frames. The kids have to push them with their feet and learn to ride on two wheels without knowing it. It's a steady progressing with no backward steps. If I get reincarnated I'm going to buy my kids those from the start.

Similarly, when it comes to sharpening, I think it's best to muddle through without a jig right from the start. When is the right time to take the jig away? Probably a long time before you actually do it. When you finally do, you'll be crap at sharpening again, for a while. It takes a lot of courage to throw the trainer wheels away.

Sorry for being preachy. My $0.2 worth.

Gadge

Re: Blue Aoto

Posted: Sun Oct 18, 2015 8:35 pm
by Brian
Not always, especially for touch ups.

Even So Yamashita recommends setting bevels with a jig.

Odd stuff that I can't jig I will do entirely by hand.

Re: Blue Aoto

Posted: Sun Oct 18, 2015 11:27 pm
by dmccurtis
I typically sharpen freehand, but jigs certainly have their place. I use them when changing bevel angles, and for rehabilitating eBay chisels with severely rounded bevels. In either of those cases, I wouldn't want to be without a jig.