In this video I demonstrate the Nubatama Ume 6000 Grit waterstone. This stone shares characteristics with the 4000 grit Ume stone. Like the Choceras, both the 4000 and 6000 grit Ume stones should not be soaked for long periods of time. As with any stone, care should be taken to not let them dry in direct sunlight or subject them to freezing temperatures.
The two knives used in this demonstration are a Tojiro DP Nakiri and a Moritaka Chukobocho or Chinese style vegetable cleaver. The Tojiro knife is a clad stainless steel blade, perhaps VG10 and the Cleaver is one I had made when I visited the Moritaka family in Japan. Watching your knife being made by a 26th generation knifemaker was a unique experience for me. Please look over my youtube channel to see videos of him making it. The cleaver is a clad design with an Aogami Super core and a nonstainless cladding.
Stone porosity characteristics were quite similar to the 4000 Ume stone - splash and go, quickly saturating and just requiring an occasional spray. Extremely smooth surface.
It is a hard stone that develops a fine black swarf with little mud accompanying it. It acts a good bit like a natural polishing stone. It could be used for chisels, straight razors Edge Pros and other precision guided devices.and other applications requiring a hard stone or for those preferring a hard stone. An easy stone to use. Excellent push and slice cutting performance.
I go on to the Moritaka Cleaver. Smooth, reacts very well to the carbon steel. A very quiet stone. Produces an exceptional edge as good as anything else out there.
These stones are available at Chefknivestogo.com in Ken's Corner: