Sypderco Fine and Ultrafine ceramic stones cupped... do I fix them?

[mpikas]

I picked up a pair of spyderco fine and ultrafine ceramic bench stones a couple of weeks ago. I finally had to use them for something that requred precise flatness and found that both are cupped, the fine along the length (like a section of the wall of a pipe), the ultrafine with it'd length (like a banana). Doing a bit of goggling it looks like a few have experienced the same thing and I'm betting if I sent them back to spyderco they would replace them but I'm not sure that they would be better (maybe I'm wrong?).

If you have one, is yours flat?

Can they be flattened? How?

If I did try to flatten them on a diamond plate would I dull the diamond plate?

 

[BluntCut MetalWorks]

I picked up a pair of spyderco fine and ultrafine ceramic bench stones a couple of weeks ago. I finally had to use them for something that requred precise flatness and found that both are cupped, the fine along the length (like a section of the wall of a pipe), the ultrafine with it'd length (like a banana). Doing a bit of goggling it looks like a few have experienced the same thing and I'm betting if I sent them back to spyderco they would replace them but I'm not sure that they would be better (maybe I'm wrong?).

If you have one, is yours flat?

No, M+F+UF are far from flat

Can they be flattened? How?

Diamond plate XX or X. Do not use finer grit plate, most likely ruineous.

If I did try to flatten them on a diamond plate would I dull the diamond plate?

Yes.

Note: a UF stone is just a flattened F stone.

I flattened all my ceramic stones. For medium & fine grit, I use the edges of M & F stone (original surface). I need very flat sharpening surface for razor & hairshears.

 

[Obsessed with Edges]

Keep in mind, the factory surface finish is the only thing making the difference between F and UF, on Spyderco's ceramics. They both use the exact same abrasive and binders (and their Medium uses a different binder and a different surface finish, but uses the same abrasive grit as their F/UF). Flattening both with a diamond hone may very well leave both with essentially identical finish. (Edit: I found this out the hard way, with a Spyderco Doublestuff pocket hone; flattening both sides left both the 'Medium' and 'Fine' sides indistinguishable from each other, in terms of the finish. Both sides are now somewhat beyond what I'd assume is at least UF; almost glassy).

I'd send them back to Spyderco, and let them either fix or replace them.


David

 

[David Martin]

I leveled my fine Spyderco ceramic stone using a coarse diamond, then on to a fine diamond. It worked but it was not so far out of level. Plus, I now have one side of this stone is fine and the other side ultra fine.
The ceramic will eat away at the diamond plates so, use lots of water. 2) One really needs some understanding of what they're doing and can tell it by looking. A lot of elbow grease and can spare losing a diamond stone or two helps. Having done this, I'd return it as Obsessed suggests with a descriptive note as to why. Let us know how it goes. DM

 

[Jason B.]

Once you grind the surface its never the same.

Though the sacrifice of a fine diamond hone to one side of a UF ceramic can produce one impressive polishing stone

 

[hardheart]

it is also not a fast process, so if the surface imperfections are significant, the wear on your arm and diamond stone might be worth return shipping.

 

[pjwoolw]

I like allot of the Spyderco stuff but have held off on the bench stones for the reasons mentioned.

 

[mpikas]

Arggg... I didn't realize that the F and the UF were the same stone, only with a different finish When I tried to see if they were flat (just tried lapping them on a flat surface), I was pretty annoyed in that they seemed to have what looked almost like the rings that you'd see from something cut by a circular saw cut into the surface, so I figured that they really look like they were just cut out of a bigger block of the stuff and shipped as they were cut. I guess that this leaves me only with the choice of talking to spyderco... I'm not ruining a diamond plate to get their stones flat and one of the big reasons I got them was as a final step for things like plane irons, which have to be flat...