Thread: 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 ?

Originally Posted by mainaman

I take it that is a superstone ?

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

Originally Posted by JimmyHAD

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

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.

Originally Posted by keenedge

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

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

Originally Posted by cotdt

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

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.