Naniwa aotoshi technique

I'm trying to improve my sharpening technique using my Naniwa aotoshi stone. So far I have not had good results.

The edge tends to dig into the stone leaving marks or gouges. This dulls the edge.
I think I am using too much pressure AND holding the wrong angle with respect to the motion of the blade across the stone (not the bevel angle). I tend to skew the blade a bit which works well on my lower grit stones.

For those of you that have good results with the aotoshi, how much pressure do you use?
How do you measure the pressure?

Thank you.
Ben

Big Green Brick? If so, it's very similar to the synthetic Blue Aoto I have.

I have the following suggestions:

Light pressure -- which is more or less true of all waterstones, synthetic or natural. These are NOT like Arkansas stones or similar oilstones that require significant pressure to cut.

Practice holding the knife at a constant angle to the stone -- those synthetic Aoto stones are very soft, and you will indeed dig gouges out if you are not careful. Took me a while to get the motion down. Getting a good edge off that soft stone greatly improved the sharpness of my knives, by the way, since I was also holding the angle better on other stones. Have a care to adapt to the different height of the stones, too, it's easy to use a different angle if the stone is higher or lower!

I suspect the Naniwa is similar to the blue one I have -- you will get a lovely, toothy but polished edge from that stone on softer knives ("cheap stainless" in KKF terms), but harder knives will feel somewhat blunt if you stop with the stone, and will require a finer stone to give a good edge.

Allowing mud to build up as you sharpen will result in a more polished edge than if you keep the stone clean as the abrasive appears to be friable, and will break down into finer floating grit and rolling/skipping free grit that polishes more than it cuts. I'm assuming the Big Green Brick is similar to the blue synthetic Aoto as I think it is (contains some natural stone ground to powder along with synthetic grit).

I've also been using mine on woodworking tools, but can't say at the moment if it is better than a 3000 grit synthetic stone, I'm still in the process of repairing severely worn plane blades -- they don't cut like knives, and most of the wear is on the flat side of the single bevel, resulting in hollowing out the flat side just above the edge. With severe wear from never sharpening, it takes an eternity to grind out the hollow and get a good edge. I cannot imagine how much effort it took to use those planes in the condition I got them!

Peter

On a soft stone like that, apply pressure only on the edge trailing stroke and just allow the blade to ride on the stone on the return (edge leading) stroke.

In addition to above, maybe the Sharpie trick could help with angle observation and adjustment?

Do you think it would be enough to simply slow down a bit so that you can anticipate when you are about to dig into the stone? I have a SS 10,000 and that's what I had to do on that stone. It revealed quite a bit about how much I was "waving" the knife when I sharpened and other stones simply didn't provide that instant feedback. Kind of like the way distortion hides sloppy guitar playing. Just a thought, and probably worth skipping!

im not a betting man but i second monty. if your digging into your stone id think you are wiggling your angle too high when you push the knife forward. likewise i think on harder stones you are likely rounding your edge as its more difficult to actually cut into the stone.

Hi Benny. Just do like Pensacola says. If you still are digging into the stone, you can apply your edge trailing stroke and then lift the knife to put it back to the position to another edge trailing stroke, like Vincent from Korin is doing here

[video=youtube;JCYI7lk3eKY]https://www.youtube.com/watch?v=JCYI7lk3eKY[/video] .

If the knife gouges in to the stone that means that the angle is wrong or you wobble on your stroke. Both are bad.

I personally do not like the green brick. I could not find the joy. Once in a while I take it out for a spin, but it never delivers. I recommend to get some other stone to practice. If you are in US and looking for 2K range, Gesshin 2K is very good option. Much better feedback, does not gouge with any minor mistake and its bloody fast.

Ruso said:

I personally do not like the green brick.

Click to expand...

+1...supposed to be good for cheap stainless...I don't own cheap stainless. I found it worthless on nice carbon.

you need to develop slurry before using it, i recommend a dmt mini plate. cktg has a mini atoma plate i've been meaning to try.
green brick is good for finishing stainless knives, that's it.

I found this online.
http://kramerknives.com/sharpening/

The neat little tidbit I gleaned was about pressure. He recommends 4-6 lbs to start lightening to 2-3 lbs to finish AND using a kitchen scale to measure.
I think the kitchen scale is a great idea. I'm sure pressure will depend on the knife steel/stone materials but using the scale should be a great way to judge how much pressure you are using and to develop a bit of consistency.

I've had this stone for a couple years and it's my favorite stone. Of course all I have to compare it to is a 1k/6k king. It is very soft and I still do occasionally take a gouge out of it but not often. It really does help become a better sharpener as you know when you mess up. Try sharpening your knife like you would a pocket knife. Heel to tip in one pass. That way you won't rock the knife. Takes a little longer though. That way you'll learn the feel of the stone and how your edge rides on it. Once you develop the burr on both sides slow down with alternating strokes and let the mud thicken and turn dark with swarf. This will really burnish the edge but it will still have bite. Besides "cheap" stainless also works very well on "cheap" carbon like my cck slicer and forge craft chef