Thread: Ceramic Naniwa 12000?

Originally Posted by Scookum

I soak mine for about 5 minutes. Some just spritz water and go. I just figure its a wetstone a should stabilize in water before using but thats just me.

I've read, in recent threads, of synthetic wetstones developing cracks or wandering out of flat from repeated soaking and drying. It's probably worth a little care to keep them away from temperature extremes, too.

I'm a little concerned about this too. Could someone knowledgeable please post the does and don'ts regarding the correct (safe) treatment of Naniwa SS and Chosera stones?

Originally Posted by CatMan

I'm a little concerned about this too. Could someone knowledgeable please post the does and don'ts regarding the correct (safe) treatment of Naniwa SS and Chosera stones?

From what I can recall (the instructions are in japanese on the stone, I don't read japanese).

* soak choseras for 15 minutes or so, but never more than an hour. Allow them to try in a "normal" temperature environment, keep them away from hot areas and direct sunlight, and don't let them freeze.

* superstones, generally splash them when you want to use them. They are not hard enough to need to be soaked. I don't know what their binder is, either - probably a soft resin binder, but the choseras are magnesia.

Don't let either of them soak indefinitely and don't forget about them even for several hours. Don't subject them to wild temperature changes.

And don't worry too much about the instructions, just think of them as "don't soak your stone forever and don't use or store them in hot or sunny areas"

Originally Posted by DaveW

From what I can recall (the instructions are in japanese on the stone, I don't read japanese).

* soak choseras for 15 minutes or so, but never more than an hour. Allow them to try in a "normal" temperature environment, keep them away from hot areas and direct sunlight, and don't let them freeze.

* superstones, generally splash them when you want to use them. They are not hard enough to need to be soaked. I don't know what their binder is, either - probably a soft resin binder, but the choseras are magnesia.


Don't let either of them soak indefinitely and don't forget about them even for several hours. Don't subject them to wild temperature changes.

And don't worry too much about the instructions, just think of them as "don't soak your stone forever and don't use or store them in hot or sunny areas"

Hi Catman / DaveW: I've just bought a set of stones from this German outfit as they sell them without the plastic glued holders, something that is not available here in the UK. On their website they say this:

IMPORTANT NOTE on storage and lubrication: Chosera sharpening stones are bound with magnesium and so have more cutting particles per unit of surface than resin-bound stones. But magnesium-bound stones are much more sensitive to prolonged exposure to water as other types of stones. So Chosera stones should NOT be left to soak in water for prolonged periods and must be stored dry. If this advice is not followed the stones can develop hairline cracks or the binding material can be leached out of the stone. It is more than enough to pour a little water on the surface or briefly dip the stones in water, they do not need to be soaked. If you are not sure that you can keep this always in mind, perhaps because you have a number of different kinds of sharpening stones, it may be better to opt for the more tolerant Super Stones.

It looks like the Chosera's are more intollerable to soaking than the SS. I dont think I'll be soaking any of mine, unlike the Nortons.

Japanese Waterstones: Naniwa Chosera

I had crazing on my cho 10k before I sold it. Nothing that couldn't be lapped off and nothing you could feel with a razor.

But as far as dipping them real quickly, they are an entirely different animal with 15 minutes of soaking than they are with just a dip or splash, and for the better. I only have two left (the 400 and 3000), but both of those also respond so well to the 10 to 15 minute soak. the 3000 goes from a very blah hard feeling stone to one that is exceptional action with a 15 minute soak.

It may make no difference on razors, unless you're restoring, you'd spend no time on anything but the 10k, and even at that, not much time on it.

But for tools, the short soak gives them such a super feel compared to any other synthetic stone with that hardness.

I have had trouble with some vendors in the past, not being willing to tell me what's in stones. When I ask a vendor what type of binder a stone has, even in general terms, and they tell me it's a "trade secret" or "proprietary information"...well, i don't like that.

I sure have never asked stu tierney a question like that and didn't get an answer.

I like the choseras best of all stones I've tried for woodworking, but soaking a stone and remembering to get it out when you use a stone several times each session for woodworking is a recipe for disaster where I'll leave one in for a day sooner or later, so my choseras get spot duty while the shapton pros get used the most. Even the shaptons feel a little better with a soak, but they also cannot be left in water, and I rarely bother to do it.

Originally Posted by DaveW

I have had trouble with some vendors in the past, not being willing to tell me what's in stones. When I ask a vendor what type of binder a stone has, even in general terms, and they tell me it's a "trade secret" or "proprietary information"...well, i don't like that.

Unless the vendor actually made the stones, or has a binding contract with the manufacturer, the only reason I can think for not telling what the binder is is that they don't know. Ancient Chinese secret, my a$$.