Ceramic bench stones?

Blue Sky

Blue Sky

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I'm looking for recommendations for good ceramic bench stone, 2"x 6" or thereabouts, in medium and/or fine grade.

I see Spyderco has some in this range, but I've read reviews that warn they are not always flat. Is this a fair assessment? If so, are there remedies?

Any experienced input about these is appreciated!
 
Ceramic stones like the Spydercos won't be flattened by anything less than a diamond hone, and it'll still take a LONG time to do it (I've done this to 3 of my pocket-sized ceramics; it still takes hours). They're EXTREMELY hard and wear-resistant. They aren't like the other waterstones (some in 'ceramic' grit, but the binders are completely different) or oilstones, in that the binders in those stones will give up abrasive a lot more easily. The sintered ceramics are bound by extreme heat, essentially starting to melt the ceramic grit together in the stone; once bound, they're almost indestructible, save for cracking/breaking if dropped.

Concrete or ceramic tile won't touch these. And lapping/flattening on a diamond hone will still likely change the effective grit of a ceramic hone (usually smoother, sometimes much, much smoother). If not done carefully at light pressure, with water, it may also shorten the life of the diamond hone, by ripping out the abrasive grit from the nickel substrate.

If not flat, the better option is to send it back to Spyderco, and have them replace it.


David
 
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While I agree with Obsessed as concrete won't do it. I purchased Spyderco's fine 2x8'' stone in the blue plastic box and leveled the worst side of this stone which needed some. I used lots of H2o and a used coarse DMT stone first then on to a fine and it turned out very good. Smooth, flat/ level and finer on one side. It may have taken me 45-55 mins.. Some of these stones come level some not. Still, they are good stones and hard. I'm glad I did my ceramic stone as I gained some respect for this stone's quality. DM
 
I have read about the stones not being flat before.

I honestly have not ever bothered checking mine to see if they need any work done or not though.
 
Harbor freight sells a 4 side/grit diamond sharpener that looks like a cheese grater thing that I used for flattening my one Spyderco stone. I have DMT's in C, F, & EF but I didn't want to suck the life out of them when I needed to flatten my fine ceramic stone. Cheap and can be used several times since it's got 4 different 2x6" plates attached to it in 200, 300 400 & 600 grits.
 
GCG199 said:
I have read about the stones not being flat before.

I honestly have not ever bothered checking mine to see if they need any work done or not though.
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If they were uneven I'd expect you would see a funny wear pattern after a short time, so maybe yours are good.

OK, so not flat is not uncommon and making it so is not the easiest thing do w/o diamond of some kind. I'm less inclined to go that way than I was, which is unfortunate since ceramic seems like a good option otherwise. Thanks for all the input.
 
I have used the harbor freight diamonds to flatten Norton SiO and some old mystery whetstones. They worked great. I have the four sided box and the set of 3 2X6 plates which are even coarser than the box. That being said, I would be hesitant to use them on my shaptons or any other more costly stone. The 140 grit plate that cktg sells seems a good compromise for those who are squeamish about degrading their DMT or Atoma plates. Personally I treat sharpening equiptment as consumables and the DMT aren't you that expensive. Russ
 
Blue Sky said:
If they were uneven I'd expect you would see a funny wear pattern after a short time, so maybe yours are good.

OK, so not flat is not uncommon and making it so is not the easiest thing do w/o diamond of some kind. I'm less inclined to go that way than I was, which is unfortunate since ceramic seems like a good option otherwise. Thanks for all the input.
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No. The reason you don't see a 'funny wear pattern quickly' is because they are hard to wear. Hence, the need to rub them with a diamond plate in order to level. I suspect they will last yours and a son's lifetime. DM
 
Blue Sky said:
If they were uneven I'd expect you would see a funny wear pattern after a short time, so maybe yours are good.

OK, so not flat is not uncommon and making it so is not the easiest thing do w/o diamond of some kind. I'm less inclined to go that way than I was, which is unfortunate since ceramic seems like a good option otherwise. Thanks for all the input.
Click to expand...

I wouldn't prematurely rule them out based only on a fear of them not being flat; that's a warranty issue. So far as I know, Spyderco has been good about replacing or otherwise fixing issues of un-flat hones returned to them. And you may not need that anyway, as the reported issues of un-flat stones seems to be hit-or-miss. This is pretty common with ceramics of other brands, as well; seems to be a by-product of the manufacturing process, sometimes. If checking by placing a steel ruler's edge across the hones, I've seen some concavity or warp in Spyderco, Fallkniven and Lansky ceramic hones, though most aren't severe enough to present a real problem in use.

Regarding the 'funny wear pattern', I think the common issue, if there is one, is the edges of the stone being raised a bit (stone's surface slightly concave), so the edges will begin to show more wear before the central portions of the stone. The edges will begin to appear a little shinier over time, as the stone is used. Even so, the edges may not present an issue to sharpening knives anyway, as the curved edges of most blade profiles won't spend much time in contact with the stone's edges. Concavity of the stone is more of an obstacle to those sharpening dead-straight edge profiles, such as for chisels and plane irons used by woodworkers.

Some ceramics may also come with bumpy edges and/or bumps in other portions; those can usually be burnished out with some light rubbing of a diamond hone, and it usually won't take nearly as long to do it (and Spyderco will fix/replace these also, if returned to them).


David
 
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