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

11 Mar 2011

Nakayama?? Karasu - A lot of power in a small package #8-15000

In view of some of the comments to my latest post regarding the Aka-pin stones, I am not sure if I dare to describe this stone as a Nakayama, even if it looks very similar to other stones on the Internet stated to be Nakayama karasu and as it was was sold to me as one. I will thus merely call it a Karasu stone, and that it definately is! I have previously reviewed another one of my karasu stones here:

This little beauty might very well have a different origin than Nakayama. However, the origin is of merely academic interest to me as the real purpose of my stones is to sharpen my knives, kanna and chisel to a useable level. Actually most of my knives are way sharper than just useable, due to me sharpening them a lot more than strictly required.

This particular little stone was one of my first Japanese natural stones, and even after trying a magnitude of different stones this little beauty has earned its place in my setup as one of my absolute favourites. It is fairly hard, maybe around Lv4, very efficient and exactly the perfect grit range for most of my kitchen knives, leaving a nice mist and haze on my kasumi blades and a very keen edge with just the right amount of bite to it. Karasu can also be fairly soft and Maxim at japanesenaturalstones have a very nice and soft one that I hope to experience one day.
A beautiful stone alltogether. I love it!

Small and thin but very clean and free of cracks

Beautiful karasu like a modernist painting. A true gemstone.

The board is light grey with spots of greenish to yellowish in it and with a dense karasu pattern showing a shine in the dark mica in the stone making the karasu so efficient as a sharpening stone. I looks like it has got a perfect camouflage. It also shows some nashiji pattern enbetween the black karasu. This stone has really got it all.

The white lines in the board looks almost like paint spill on the stone and is close to the same hardness as the rest of the stone and thus of absolutely no consequence to the sharpening.

When sharpening, the stone pulls black metal filings immediately proving that this is a very efficient and fairly hard stone. You can see the metal filings suspended in the clear water before a slurry has built. This is usually a good sign, but it is no guarantee for the stone being a good sharpener or finisher. It is just a proof that the stone removes metal, which is only one of several things a good stone will have to do.
Black metal filings suspended in clear water = extraordinary efficiency.
After about 50 strokes on the stone, a dense dark olive slurry builds, making the sharpening experience a lot smoother and creamier. Not that the stone is scratchy. It isn't, but the feel of the stone changes as a slurry builds up. The stone is not very thirsty and the slurry holds up for a long time befor I have to add water to it. This provides for a very consistent result as I can concentrate on the sharpening and not consistently add water to keep the slurry within my comfort range.
Dense dark slurry building up
When looking at the finish, you can still se a few very light scratches, mainly in the soft steel jigane. This might be a result of poor ground work or me being a little bit too impatient. The edges off this stone, however, is some of the keenest edges I am able to produce on my knives. Especially on regular kitchen knives like my gyuto, nakiri and santoku. Exceptionally sharp but still with a very nice bite to them making the knives a pleasure to use both on proteins and veggies. It is a highly versatile stone handling all the types of steel I have thrown at it equally well, from soft 440C to blue #1 honyaki. That is an unusual but highly desireable feature for a japanese natural stone.
Not a high polish finish, but a very keen edge
From my experience it seems to me that karasu stones are generally efficient sharpening stones. However, I have heard that karasu stones, like asagi, can be quite scratchy and produce poor results if used unwisely. If you can find a good one, it should be a part of any Japanese natural sharpening stone set-up, but as these beauties are becoming quite rare you will probably have to expect a high cost. I really love this stone. It looks beautiful and is an excellent performer. My only whish is that it was a little bit thicker, but a full size stone of this quality would be dramatically out of my reach pricewise if at all available.

However small, this little stone is an absolute pleasure to use and one of the very few true gems in my collection. As it is a fairly hard rock, hopefully it will last a long time.


8 Mar 2011

2x Nakayama Aka-pin review. Variations on a theme...

I bought two Nakayama Aka-pin stones from in the same batch. The long and thin one was stated as a Lv3 stone and the wide and stubby one as a Lv2+ stone. Not looking at the size, the two stones look and feel very similar to each other. Roughly the same colour and the same lotus pattern, similar surface feel and fairly similar in hardness. I thus expected them to be relatively similar in performance and use. I could not have been more mistaken. The two stones, however similar would prove to be as different as two stones can possibly be, being approximately the same hardness and grit.
The two Nakayama Aka-pins looking very similar.
I name the top one Aka-pin #2 and the lower one Aka-pin #1

Nakayama Aka-pin #1 close-up

Nakayama Aka-pin #2 close-up

For this review I used my trusty Kasahara Aoko #2 kasumi usuba from Iida Tools (as usual). Using the same knife for all my stone tests makes it easier to compare the results and posible to compare results over time.

I started out with the #1 stone. It is long and narrow and quite thin, but very clean and without significant cracks. Just a few hairlines in the board. The surface is red to orange and full of darker lotus patterns. It is a nice looking stone.

I was amazed by this stone from the first time I used it. I sprayed the stone with a little water and started sharpening. The stone pulled metal filings from the first stroke leaving the metal particles floating in clear water on the surface. I was really amazed by the efficiency of this stone. After about 30 strokes, a dense dark grey slurry built up making the sharpening experience really smooth and creamy. The dark colour of the slurry is due to a significant part of it being removed metal. 
A dark grey slurry coloured by the metal filings

Metal filings floating in clear water after a few strokes

The real surprise came when inspecting the result of the sharpening session with the Aka-pin #1. A totally smooth and even scratch pattern and excellent contrast between ji and ha showed up under the slurry. I could not believe my eyes. Could a stone this fast, agressive and soft be this fine? Obviously it could. It was obvious to me that this little stone was of excellent quality and that the price paid was a bargain.
An almost flawless result from the Aka-pin #1
Next up was the Aka-pin #2. A somewhat larger stone. Wider and thicker, but a little shorter. Approximately the same colour, but Aka-pin #2 have some really nice ring formed lotus patterns that I have learned should be a sign of better grinding force. Could this stone possibly be even better that Aka-pin #1? If so, I would be a very happy dude, indeed.

I started sharpening the same way. A good spray of water on the surface and on with the steel. It was soon apparent that this stone was not only a little softer than Aka-pin #1. It was a lot softer and a lot more thirsty. I had to soak it for a couple of minutes to be able to keep enough water on the suface to build a slurry.

The sharpening feeling was quite similar to the Aka-pin #1 except the Aka-pin #2 gave up a slurry a lot faster than the previous one. The slurry was a light tan to orange colour without signs of grey, showing that this stone was not even close to the efficiency of the #1 stone. I sharpened a while on the slurry hoping to see an even finer result on the blade road due to the softer stone and apparently less agressive abrasives.
Stone coloured thick slurry showing no trace of metal filings
I was totally wrong in my expectations. The stone left a significant scratch pattern on the blade road and with a lot less pronounced contrast between ji and ha. I tried the stone on my VG-10 gyuto and my Aoko #1 Santoku just to see if it was equally poor on all steels, and it was. This stone is absolutely useless as far as I can judge it. It has a nice look, but as a sharpening stone it is absolutely without value. It will make a nice paper weight at work reminding me to never taking anything for granted when buying stones on the internet. If it had been an expensive stone I would have returned it, but as the return shipping in this case would be considerably more expensive than the stone itself, I'll just write it off on the lessons learned account.
A very significant scratch pattern for a stone this soft.

So what have I learned from this endavour? Never to judge a stone by its looks. Never to expect anything from a stone before I have actually tried it. That two very similar stones from the same mine and strata can perform very differently, and finally that buying stones on the internet is a gamble where you can make real bargains as well as really poor deals. Luckily the bargains have greatly outnumbered the bad deals on my behalf so far. That said, even the bad stones provide me with experience and knowledge about the complex world of Japanese natural stones.

Be prepared to do a few mistakes to score the good stuff. You can of course remove a lot of the risk by buying certified and expensive stones, but personally I find the treasure hunting very exciting and I urge you all to try and find your own jewels amongst the heaps gravel out there. Win or loose, it is exciting anyhow, and highly educational.