砥石
The Japanese waterstones are essential to the sharpening of the ultra hard steels. They are finer than most synthetic abrasives and require a special technique in use. Creating a slurry aids in sharpening. Some of them are hard and the slurry is made using a harder coarse chunk of stone named "nagura", others are softer enough to create it during use. My natural stones are from the later category. They are suitable for intermediate skill.
Nakayama Karasu (Black Crow Point) named from the black specks found inside. These are concentrations of mica which improve the abrasion action. The base is wild cherry ardried and carved from one piece with natural edges (bark) finished with linseed oil. It is an excellent stone for the last finishing step of the japanese laminated knifes. The grit is 8.5 on a scale from 1 to 10, the hardness is 8 and ease of use 8.5. The dimensions are on average 10" lenght, 3" maximal width and 0.6" in thickness. It is a Grade #24 stone but half thick. It still has some 50-60 years of use left. The stone is sold now! As a last mention, a stone this size and quality shows on the eBay, once a year. It's really not common. |
The back of the Karasu stone. From the colour of the skin it can be identified as a stone from the Nakayama quarry. I investigated on some sites and it seems to be genuine. This subject is somehow taboo but many japanese tools are fakes. Some of them are even better than the originals, ha ha! |
Bought from So Yamashita, this stone from the quarries of the Oohira mountain is guaranteed genuine. On it you can see the dried slurry created during sharpening. It is composed from stone particles dislodged and crushed finer and microscopic rust formed from the steel of the blade. This mix I let dry on the stone and just use each time. Just a sprinkle of water is enough each time of use. It saves a good deal from the life of the stone, lubricates and prevents the "stiction" effect. The base is some pallet softwood in one piece stabilised with purfling and left unfinished. I like the "working class" felling this stone is giving to me. A stone to be used. |
The back of the Oohira stone is lacquered with two coats of thick shellack. This slows the drying after use and protects against the apparition of small cracks on the sides. |
Japanese natural watersone form the Nakayama 礦 quarry (from my investigations). The sides are professionally lacquered with urushi (natural lacquer)and bear the stamp of the Kyoto Natural Stone Association (some kind of trade union). Can't be used straight away, I must create some paste using a fine diamond nagura plate. From this stone I have obtained the sharpest tools yet. A similar stone is this Nakayama Maruka. I found this stone by luck. An EU dealer, from which I had bought some tools ago, had listed some stones in his online store. Two of them were japanese natural stones in their original boxes. Initially I ignored them since they were not cheap. After 3 months, and studied more online I realized they were very high quality and very expensive. Their listed price was 10 times lower than market price! After a few minutes I sent the dealer an email to put an reserve and ask a price. The time spent online reading about the japanese culture and especially woodworking paid a lot. I think I would never spent the market money these stones command. |
Natural waterstone from the Hideriyama quarry, softer and very fine (So Yamashita - www.japan-tool.com - guessed the quarry). Easy to use waterstone. Excellent for knifes but I will use it for tools. |
