Just noticed these on Tools From Japan website, interesting offering for japanese style sharpening stones...
"These Dual-Stones from Suehiro manage to straddle between the two extremes of fast cutting 'waterstones' and dish resistant/low maintenance 'oilstones', offering both exceptionally strong resistance to dishing along with faster cutting and ability to work effectively with all blade steels (carbon, stainless, high speed and powder metal steels) and ceramics.
By taking the essential ingredients of a standard ceramic waterstone and 'compressing' it to reduce it's porosity, the density of the stone is significantly increased without sacrificing the ability of the stone to work with even the hardest blade steels. This increase in density also means that the stone will not wear at the same rate as the conventional stone it is based on, explaining the strong dish resistance, but at the sacrifice of outright speed.
The specified 'grit' number of these stones is correct, but the way these stones behave means that the grit number does not match how they work, as the abrasive is thoroughly used and will deliver a polish and edge equivalent to a to a much finer stone. As an example, the #1000 grit Dual Stone will deliver and edge equivalent to a stone in the #3000-5000 range, if the stone is allowed to work thoroughly.
Perhaps the most unique aspect of these stones is related to their name, "Dual Stone" as this relates not only to how they behave, but that they can be used with water or oil as a carrier for swarf. Almost any oil can be used if desired, so long as it is a 'non drying' oil that will remain fluid. If using these stones with oil, it is recommend an edible oil such as camelia oil or a low viscosity cooking oil for food cutting blades, and a light machine or mineral oil as an alternative or for blades that will not be in contact with food, or of course plain, clear water and only a small amount of whichever fluid needs to be applied to the stone prior to use, with the excess removed once finished.
These stones do not require any special care, being tolerant of most household chemicals, heat and cold as well as permanent immersion in water, although these stones naturally do not require soaking at all.
Also included in this range of stones are several diamond plates which are of course compatible with the stones, and can be used to quickly correct edges or to clean and condition the stones.
Lightweight, compact, low maintenance, durable and long lasting, these stones are something new, unique and attractive for those who require a compact sharpening kit or are looking for a stone that will be effective on blades that oilstones struggle with but without the mess of a conventional water type stone."
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www.toolsfromjapan.com]
