Shigefusa 270mm kasumi yanagiba with custom, by me, desert ironwood handle

21 Nov 2010

Nakayama honsuita 180x65x35 (koppa) #30-40000

This stone I bought from an auction at I have gotten a lot of stones from them in wholesale batches at very low prices. Some stones have been really bad and some merely mediocre, but a few have become good and even excellent stones after a bit of work with my trusty #140 diamond plate grinding trough the dirty layers on the search for a clean board. A couple of the stones I have gotten from 330mate have been real bargains. Some of the better stones are sold at their Dutch auction, but you can take even more of the uncertainty out of the equation by requesting a specific stone from them, as I did with the 130x85x33mm Nakayama koppa, but then you will have to fork up a lot more money for their efforts selecting a good quality stone for you. That said, I kind of enjoy buying batches of low priced ugly looking stones from 330mate, searching for that one jewel to be found. It has happened to me a couple of times, and it is a very exciting feeling when it happens.

This stone was actually very good straight out of the box. Well lapped, clean board and ready to go. The board shows a lot of the same colors as the previously mentioned Nakayama, with green, yellow and pink shades entwining on the board almost like waves on this one. It is a little bit narrow but has good thickness and it looks fairly uniform through the stone making it last at least my lifetime and then some.

You can see a few lines and cracks on the board, but none of them affect sharpening. The grit from the red area seems to be a bit more agressive, and pulling slurry with a diamond nagura from that area greatly enhances the speed of the stone. A little turbo grit :o) Very practical. Every stone should have one.

 The skin showing on the side needs to be ground down from the board as it is very hard.

The stone is very efficient even without using a nagura making slurry. In the below picture you can see a lot of metal filings floating in still clear water after just 10 (top) and 20 (bottom) passes over the stone. That is just amazing!

After 50 passes the stone has given up a light and extremely fine slurry making the sharpening more smooth and leaving a very fine scratch pattern and good polish. 

As you can see from this close up, the scratch pattern from the stone is very fine and homogenous. However it makes only a slight contrast between the Ji and Ha. This shows that the stone polishes both Hagane and Jigane equally well.

From the reflection picture, you can easily see the exeptionally fine finish this stone puts on the knife. This polished look is actually due to a very fine and complex scratch pattern from the natural stone. Looking at the close up picture above, the surface is actually matte or hazy to the look. This highly complex scratch pattern I believe is one of the main factors to get the edge really sharp and more wear resistant than an edge polished to a full mirror finish by fine synthetic abrasives. You can find some very good reading about this theory here can easily shave with any high carbon steel edge coming off this stone.

This stone is one of the best bargains I have made from 330mate. A really amazing stone at a very, very reasonable price.

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