Naniwa warp

I purchased a practically brand new Naniwa 3000/8000 combo on ebay the other day. Yesterday I lapped both sides and used it. This morning I pick it up and it's warped. The 3000 grit side seems to be warped the worst. The glue between the two sides has separated at the ends.

I lapped under running water and threw the stone into water with my Nortons, for about an hour, as I set the bevel on a razor.

What is going on with this warpage? Is this common with Naniwas? Anyway to fix this, other than lapping forever? I'm assuming the water drying out created the warpage, but it's a waterstone, that's pretty lame.
Thanks,

I take it that is a superstone ?
They have the warpage issue because they are resin bound and also the 8k is probably harder than the 3k.
Your options are separating this (I am not even sure how easy that is) then get granite bases (Home Depot cuts granite tile to size) and glue the two stones to the bases.
Another option is just get superstones with bases or the 2cm versions with no base and then when they start warping glue them to granite bases.
Soaking the Super Stone might not work because those stones do not need soaking they are not porous.
The warpage was another reason for me to get Choseras, they are the same abrasive but are scintered not resin bound. They also cut faster imo.

interesting, I didn´t have this kind of problems with my Super 2k/5k combo (available in europe)

I'm inclined to think the soaking may have done it. My Shapton pros need to be lapped before every honing session because of the way that they change in between uses. I've heard from a scientist in the field of polymers that is the nature of the material. The two halves separating is obviously beyond the normal 'warpage' that would be par for the course.

I have the 20mm thick Naniwas and the Shapton pros are 15mm. So far my Naniwas are moving less between honing sessions than my pros. Judging by how long it takes to remove a pencil grid that is. Pehaps if you notified the ebay seller that the stone is defective he might replace it ?

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Originally Posted by mainaman

I take it that is a superstone ?

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Yep, it's a superstone. Nothing super about this one though....:rant:

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Originally Posted by JimmyHAD

Pehaps if you notified the ebay seller that the stone is defective he might replace it ?

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I purchased it used and part of a package with a couple other items. So returning isn't really an option. I'm not out a lot of money, that's one good thing. :)

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Originally Posted by keenedge

Yep, it's a superstone. Nothing super about this one though....:rant:

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What about that fine sharpening-taste, as natural stone gives?

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Originally Posted by cotdt

What about that fine sharpening-taste, as natural stone gives?

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I can hardly look at it, let alone taste it. ;)

You are NOT supposed to soak these stones.

Says so right on the package. Soaking them will ruin them.
**EDIT** OK, so I THOUGHT it said so on the package...but I just checked mine and it said nothing.

Weird.

But I could have SWORN someone told me not to soak them in water...

My Naniwa Choseras had a stamp on the side of the stone that warns against soaking for more than 40 minutes. So the hour or so was probably too much. Nonetheless the hones need about 15~20 minutes prior to use anyways.

There is a warning on Shaptons (pros, I believe) not to soak them.
The problem with soaking Shaptons was that the surface of the binder
will get muddy and unusable (that´s what it said)

Naniwas can be soaked, I believe.
If not, there would have been way more problems with the naniwas
being soaked, that come with a stand!

I think, maybe there is just something wrong with your 3k/8k?
IDK, if anybody else encountered such problems (I don´t soak, so I can´t tell)

I have the Naniwa 3k/8k combination stone. When I use this stone it gets soaked but I'm too impatient to wait any more than about five minutes before I want to start honing. However when I'm using other grit stones the Naniwa sits in a bucket of water. This doesn't seem to have caused my Naniwa any problems. I'm thinking maybe you were just unlucky enough to get the one defective stone.

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Originally Posted by JimR

But I could have SWORN someone told me not to soak them in water...

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Here is what a friend of mine who lives in Japan found out for me by calling the companies directly this past August; :)

" The very nice lady at Shapton told me that the DGLP is fine for use with the Pros, and that the best way to do it is to use lots of running water, rather than spraying or soaking. It washes away the slurry and keeps it from building up too much.

I tried to ask about the 12K thing being for Stainless, and she tried to explain but my Japanese just isn't good enough. Something about being harder, but I don't know just WHAT is harder. Sorry about that.

The Naniwa guy said that it isn't necessary to soak the super stones, but it wouldn't necessarily hurt, either. Like Shapton, lots of water will help wash away the slurry.

The Naniwa stones are all the same material, and they don't differentiate for stainless/carbon etc. like Shapton, so they don't seem to have a set recommended system for sharpening."

Jimmy, what an amazing friend you have! ;) So, I guess I was wrong about the Naniwas...

She said that the Naniwa 12k is bad for stainless? I use it all the time for my S90V, VG-10, ZDP-189 knives and it worked great!

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Originally Posted by cotdt

She said that the Naniwa 12k is bad for stainless? I use it all the time for my S90V, VG-10, ZDP-189 knives and it worked great!

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If you're referring to what the lady told my friend in the post above .... it was about the Shapton Pro. The Shapton USA faq mentions that the 12k is for stainless and my friend wanted to know how it differed from the other hones. There was no mention of the Naniwa 12k and stainless steel in that conversation.