The Gou is VERY, VERY hard by comparison to the other knives (63 hardness). it's also at 9-11 degrees bevel. Of course the only way to do a good job is on stones. Because the Gou is SO hard and SO fine I would not even do it on the same day as those other "clubs". If you're not good at sharpening, have a professional do this one. It would also be a shame to ruin that beautiful mokume (dragons breath pattern).
Edited by harrisonh - 1/3/16 at 6:03pm
The Wusty and the Vicky are German steel so they're very, very soft at about 56. This also means you have to sharpen it MUCH more often. They are easy, From the factory the wusty is about 19 degrees and the Vicky is about 22 degrees, so even a beginner can sharpen them. And you don't need to worry about ruining the beautiful finish, like you have to worry about with the Gou.
Of course you can reprofile them. I don't think you really need to reprofile the Wusthof. There IS a good reason for having it at 19 degrees. I think it's perfect. And reprofiling the German knives much more than 19 degrees is counterproductive. I might THIN the Wusthof, but I wouldn't reprofile it. It just means that you will need to hone even more.
I absolutely would reprofile the Vicky down to 19 degrees unless you're just using it for hacking bones or deboning large slabs, but any finer than 19 degrees is useless
Just use Japanese stones for all the knifes. There is nothing special about Japanese stone for a Japanese bade and American or French stone for a German knife. Japanese stones are the most reliable and long lasting and their grit is pretty much standardized and recognized throughout the world.
Personally I prefer stones of "all one grit" over "combination" stones. They last longer. I also recommend "splash to wet" stones (although I always really soak them, they are easier to REwet).
There are some guys that like to go crazy high but after a certain amount, there is not enough "tooth" to the edge. Since I'm pretty lazy, I just do once at I,000 and once at 5000 and then strop on leather. After a while there is diminishing returns. And especially on the German knives it's pointless to get them really sharp because they're so soft, the edge "rolls over" so easily.
The Kohetsu is also going to be difficult to sharpen because of hardness and fine degree, but you won't have to worry so much about the mokume. So Learn to sharpen fine edge on the kohetsu then apply that to the Yaxell Gou.