Naniwa Snow White/Chosera Cracking

Folks,

I've had a Naniwa Snow White 8k that I usually do not use, preferring my Shapton Pros and HC Glass 8ks instead, but two of my friends have had these stones, two each actually, and all 4 stones cracked to the point that they no longer will use them on razors. The stone is similar to the Choseras which have sometimes also experienced cracking.

Mine has not cracked at all, but I used three coats of undiluted brushing lacquer applied with a foam brush to seal the sides and back, and after each use I wrap it loosely in a dish towel to slow the drying. Even under magnification there are no cracks. Yet, the experiment continues.

During my initial tests I noted that the stone is extremely thirsty, and it also absorbed that first coat of out-of-the-can lacquer like it was nothing. So I believe that the cracking is being caused by the stone absorbing a lot of water then the outer layers drying too fast and shrinking, resulting in the observed cracks.

There's some anecdotal evidence of such behavior, the most prominent are those ventilated boxes Shapton uses on the Pro line to control the drying rate. Those boxes cannot be cheap and they would not use them if there was not an understood reason for it. They also appear to have sealed the sides on the current series and the sides and back on the previous series with the graphics on the back. BTW the Snow White will not fit in a Shapton Pro box, it's too thick.

Anyway, the lacquer and towel were meant to mimic what Shapton did and I've had success so far, so I thought I would post in case the information might help others. I also note that Max at JNS now recommends sealing synthetics.

Cheers, Steve

Quote:

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Originally Posted by Steve56

Folks,

I've had a Naniwa Snow White 8k that I usually do not use, preferring my Shapton Pros and HC Glass 8ks instead, but two of my friends have had these stones, two each actually, and all 4 stones cracked to the point that they no longer will use them on razors. The stone is similar to the Choseras which have sometimes also experienced cracking.

Mine has not cracked at all, but I used three coats of undiluted brushing lacquer applied with a foam brush to seal the sides and back, and after each use I wrap it loosely in a dish towel to slow the drying. Even under magnification there are no cracks. Yet, the experiment continues.

During my initial tests I noted that the stone is extremely thirsty, and it also absorbed that first coat of out-of-the-can lacquer like it was nothing. So I believe that the cracking is being caused by the stone absorbing a lot of water then the outer layers drying too fast and shrinking, resulting in the observed cracks.

There's some anecdotal evidence of such behavior, the most prominent are those ventilated boxes Shapton uses on the Pro line to control the drying rate. Those boxes cannot be cheap and they would not use them if there was not an understood reason for it. They also appear to have sealed the sides on the current series and the sides and back on the previous series with the graphics on the back. BTW the Snow White will not fit in a Shapton Pro box, it's too thick.

Anyway, the lacquer and towel were meant to mimic what Shapton did and I've had success so far, so I thought I would post in case the information might help others. I also note that Max at JNS now recommends sealing synthetics.

Cheers, Steve

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I wish I would have thought of sealing my Chosera's.
Maybe i should try that with the 10k.
The 5/10k are like crazy paving , although it doesn't effect the honing.
I'm starting to wonder how deep the cracks are and if I could lap them away?
Either way I keep them as dry as possible nower days, apart from the 1k, I think that's bullet proof.

Thanks for this tip Steve.
I have been following the threads on the failing Naniwa's with interest as I have the Snow White as well as the new Professional 1K and 3K. Never thought to seal them but it sounds like a great idea.
First coat on my S/W is drying as I type.

Odd but true my Snow White has never been soaked, spray and go only.
I decided to use only the backside of the hone to save the providence or stamp on the front.
SW crackled on the backside only. I have been told it has to do with the binding material.
The New Professional Series and New Chosera are using a different binder which is supposed to fix the crackle effect.
I think it gives it character. Like a fingerprint. Hones just fine.

Quote:

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Originally Posted by Steve56

Folks,

I've had a Naniwa Snow White 8k that I usually do not use, preferring my Shapton Pros and HC Glass 8ks instead, but two of my friends have had these stones, two each actually, and all 4 stones cracked to the point that they no longer will use them on razors. The stone is similar to the Choseras which have sometimes also experienced cracking.

Mine has not cracked at all, but I used three coats of undiluted brushing lacquer applied with a foam brush to seal the sides and back, and after each use I wrap it loosely in a dish towel to slow the drying. Even under magnification there are no cracks. Yet, the experiment continues.

During my initial tests I noted that the stone is extremely thirsty, and it also absorbed that first coat of out-of-the-can lacquer like it was nothing. So I believe that the cracking is being caused by the stone absorbing a lot of water then the outer layers drying too fast and shrinking, resulting in the observed cracks.

There's some anecdotal evidence of such behavior, the most prominent are those ventilated boxes Shapton uses on the Pro line to control the drying rate. Those boxes cannot be cheap and they would not use them if there was not an understood reason for it. They also appear to have sealed the sides on the current series and the sides and back on the previous series with the graphics on the back. BTW the Snow White will not fit in a Shapton Pro box, it's too thick.

Anyway, the lacquer and towel were meant to mimic what Shapton did and I've had success so far, so I thought I would post in case the information might help others. I also note that Max at JNS now recommends sealing synthetics.

Cheers, Steve

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With regard to the Shapton Pro series, I have the Kuromaku (Japanese version of the Pro series). Maybe they're a bit different, but mine aren't sealed on any sides so far as I can tell, and they really don't absorb any water. Mine seem to dry in no time, but I leave them out overnight anyhow. Too lazy to put em away same day. And the insert in the plastic box is a non absorbant foam that if left where it was when shipped (Between the stone and vent holes) would block moisture from exiting the vent holes at all and sort of defeats the purpose of their existence.

Norton hones have ventilated boxes too, my guess is some folks are just too impatient to let their stones air dry thoroughly before putting them away and don't think about the havoc moisture will wreak on anything trapped in a plastic container. Mold and mildew come to mind first. My Norton hones (Specifically the 1K and 4K) always get left out on a paper towel for several days because of all the water they take in. At any rate, I would imagine that's protecting a careless user from themselves more so than controlling how the stone dries. For anyone wondering how well that works, I put my Norton 4K away a bit too wet once and came back a week or so later to find it had black fuzz (mold) that needed to be scraped off and lapped out. Beginner's error that contributed to the early demise of my original combination stone. Perhaps they're meant to be stored vent side up, and not neatly stacked on the rubber feet?

Now I heard the Kuromaku series had a similar crazing issue to the Choseras, so they tweaked the formula and re-introduced them overseas as the Pro Series. But in their case I would think it had more to do with lower humidity and drier conditions in the interior regions of the US than the stone not drying uniformly. I don't see how any sort of differential water absorbtion or evaporation could be a possible cause of the problem since it sits on top of the stone and doesn't really get pulled into it. Since I'm on the mid Atlantic coast I'm looking at similar humidity levels seen in Japan, so I'm confident it won't be an issue but...who knows? Time will tell. At any rate, I think comparing Shapton ceramics to Naniwa Magnesia bonded hones is apples to oranges.

As for the Choseras, the issue just seems weird and honestly has steered me away from them. Let stone dry too fast? Crazes. Leave stone in direct sunlight? Stone crazes. Soak them too long? You guessed it, crazes. BUT! If you don't wet it for at least 5 minutes, the hone 'doesn't work right.' What sorcery is this?

Lifted from Onimaru in one of the other threads regarding this problem:

Quote:

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Do not leave stone in water. Doing so may damage the stone. To use the stone, just splash water on it as needed.
Do not leave stone in the sun. Store the stone indoors, out of direct sunlight, instead.
Do not dry the stone with a fan. Doing so may cause hairline cracks to appear on the surface of the stone.
Do not subject stone to extreme temperature. Store the stone indoors at room temperature.
Do not wash stone with hot water. This may damage the stone. Use cold or lukewarm water instead.
Do not wash stone with soap or detergent. This may damage the stone. Use water instead.

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That and this tidbit from Gssixgun in the same thread:

Quote:

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Originally Posted by gssixgun

A thought just occurred to me that you might not want to hear :(


I really haven't had an issue, my 5k had a bit of crazing but I flipped it and haven't had an issue since

BUT

My Chosera hones are used "Professionally" basically near every day, when they are not in use they are face down on a towel that is probably damp..
Basically they hardly ever really dry out except 2 separate weeks out of the year..

:shrug:

IDK maybe the wetting and complete drying is bad for them

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Seem most pertinent to me. But who knows, maybe sealing the stone will do something to make them more resilient? I wasn't aware the Snow White had the same quirk as the Choseras. But none of this resolves anything for someone who has a stone that's already crazed...

Oh, before I forget the thread I'm referencing is here:

http://straightrazorpalace.com/hones...ra-cracks.html

Good luck JOB15, I see this has been plaguing you a while. Hope you can get the issue resolved! If you can't feel it with your fingernail or the edge of a toothpick, maybe it can be lapped out and fixed before it gets bad enough to negatively impact honing. Some of the cracks in these threads look pretty gnarly.

I appreciate some members have had some crazing on their Naniwa stones. I do not use my Naniwa's professionally, however I've been using a 1k Chosera for many years with no issues. I have used superstones from 2k,3k,5k,8k and 10k and also can report no issues with them. That is five trouble free years. You might recall a video of gssixgun's from five or six years ago, where he dunks his stones for five or so minutes before use. Well, I have done the exact same thing, since I began honing, and have had no dramas at all. I don't follow any ritual as far as how they dry, I just leave them on the floor to dry naturally. I think it must have something to do with the climate. I am on Australia's east coast, with no real extremes of weather, so I can't offer a view on why it happens to those folk who refer to this problem. I'll just keep up doing my Naniwa's the same way I've always done, with the dunking in water for five minutes, then when done, just putting them down to dry out naturally. If I ever do have a problem I'll certainly let everyone know.

One thing to add.
I believe that the 10k Chosera can be used dry.
The 5k is a bit tricky because it cracks if soaked, or at leased mine did. Yet it is the most thirsty of stones.
In saying that, the 5k is pure quality in its effects.
Very soft and fast.
If I was rich and from the 1600's I would say, "It is but a sheer delight to use"
:)

I have s snow white with a lot of cracks and 5k chosera with too many cracks, I always spray them when I used them. I always left them drying overnight right after used, so I do not think, not having ventilated plastics boxes like those by Shapton makes a difference. I think it is a manufacture issue. I have other Chosera stones the 400, 600, 800, 1k and 3k and they are fine.

Maybe it's worth approaching Naniwa Abrasives and see if it's some sort of batch issue. There are too many users with these cracking or crazing problems. As I mentioned earlier I've used Chosera and superstones for more than five years, soaking them, doing nothing remotely as far as treating them in any careful way. I've followed gssixgun's video the whole time I've been using straights and I won't be changing anything. As far as climate goes, coldest mornings in winter wouldn't get below 4Celsius, and hottest day in summer of 42-43 Celsius. We do have high humidity most of the time. I'm close to Onimaru55, as far as climate is concerned, like an hour and a half drive. I'm on my second set of superstones and never had a drama.

I've said it before & I'll say it again. My Shapton pro HNK stones get wiped with a sponge, put in their boxes & stacked. My Choceras get wiped & put on the bench out of the sun. No cracks, no crazing . Everything in our house goes mouldy except the stones :roflmao

I recall reading somewhere that the re-branding and formulation of the Naniwa line was in part, because of the crazing/cracking. And particularly the 8k. Which was why they still made some stones in both configurations, for Japan and some for export.

I have several Chosera stones and the only one that is crazed, is the 8k Junpaku Snow White, original. I cannot feel the crazing with my fingers or with a razor and it has not affected performance, it is a great 8k polisher. The bottom, label side is fine, not a single crack.

I do not soak, splash water with a squirt bottle and air dry on edge in a wooded plate rack, it rarely gets fully dry. It is a couple years old.

I have thought of buying another, just in case they decide to stop making this one, though. I would keep it boxed until and if, this one started giving me problems, I doubt I will wear it out, it is hard.
Attachment 266636

Just to make sure we're all talking about the same stone, I am talking about the original IF-001 Junpaku. There's a newer version, allegedly a little softer and coarser, the T-380. I have no experience with the T-380.

Cheers, Steve

That's what I thought too, but one of our members got the new/rebranded series and his Pro stones crazed almost immediately. I suppose there's only so much they can do without changing the function/feel of the stones. And I'm sure Naniwa doesn't want to do that.

“Just to make sure we're all talking about the same stone, I am talking about the original IF-001 Junpaku.”

Yup, same one I have, great stone.

I've used that 8K snow white for years not a single crack I just spray and go clean off any swarf then dry with towel store a dry wooden box with my other Chosera stones 1K, 3K, 5K, never soak any of them spray and go for me, the Snow white is the one with a large prawn or Shrimp printed on the stone mine as well and truly long gone through use and lapping, it's a very fine polishing stone and I would have no problem going from this 8K to my 20K .

Attachment 266650

I have my Junpaku, the original one with the shrimp, for five months now. No cracks or anything so far. I soak it for a minute or two since it's so thirsty. After use I clean it and lean it against the wall by the sink. I lap it with an Atoma.

I've been using mine now for over a year without any issues, mine is not thirsty at all. Spray and go is all it needs, have read that some are very thirsty and some aren't, makes me wonder.