Spyderco Ceramic Stone, Flattening?

[Chris Griggs]

I think I looked at the piece on the bay when Dave B was talking about this stuff, and naming the different types to look for a couple weeks ago. I'm encouraged to know that finding a good piece isn't rocket science. I'm leaving on summer vaca tomorrow, think I'll need to get myself a piece off ebay when I get back.

You gonna try shaving off of it?

[David Weaver]

Maybe once it's settled in. It's a burnisher without slurry, but whatever it would do that an escher wouldn't, or a good coticule (which is a rare thing) ....would be erased on the linen. Good vintage linen dictates the edge.

Nearly forgot, I bought George's big frictionite pair, too. So many stones, and the linen makes it literally so that I don't need to visit a stone more than once every few months, maybe once a year.

But I do like the natural stones in the shop, and the harder the better. And this one is really something because there's no wire edge coming off the slurry and it's waxy endgrain fine with no lines or evidence of crushed grain. Great stone to use lifting the handle a little.

[Chris Griggs]

Dave, you'll have to try it out on all those different steels you have in your shop and let us know how it goes. Could be just the thing for that HAP chisel of yours.

[David Weaver]

Definitely not going to hold my breath on that. The HAP loves diamonds. It might even tolerate spyderco. The jasper might burnish it, but that's what the spyderco would do, too.

Only did the easy-sharpening stanley chisel on it so far, but will try a couple of less demanding steels. If it handles anything in the A2 range (which it should do OK with on slurry) then it's already past what you can get done properly with oilstones. Not that you can't sharpen A2 on oilstones, but there are compromises doing it and softer or carbon steels are much better to stick to with oilstones.

[Chris Griggs]

Definitely would be curious to hear how it does compared to an ark on A2 and hard white steel.

[David Weaver]

Just supposition, but it will handle white steel no problem since the abrasive is loose on the surface and since white steel never fans out much of a wire edge. No carbides in any appreciable amount, either.

Fresh novaculite is fine on the hardest of white steels. Broken in, it becomes marginal. As much slurry dulling as there is with novaculite, though, of course you want to be able to use it broken in as a final step (unless stropping with compound).

My ideal finish stone for planing is still something like a shapton, no attention paid to it and stays fairly flat but cuts everyday stuff fast. I like to have a hard natural stone nearby doing joinery, though, just preference. Certainly not necessity. It's like using a strop, except geometry is never threatened.

[Mel Fulks]

David,the slurry on the jasper,produced with diamond or what?

[David Weaver]

Yes, diamond. I would imagine if someone would've had something to abrade the jasper a century ago, they'd have been a common and favorite finishing stone.

I'm sort of satisfying my own curiosity by playing with them, I don't expect that anyone else is going to go out and buy. They fit my ideal wish list for a bench side chisel stone, though, except for the fact that it's hard to find them in a slice of any fairly large size that's also thick. That's probably owed to nobody wanting to buy a 1" thick slab to buy jewelry or to "cab" whatever that means. A lot of it says "great for cabbing" or "cabs" or "cabochons". Google will tell me what that means, I envison them in pendants.

I can't imagine anything other than diamonds would do anything to their surface, they are *hard*. I have to look at the scratches on a razor under a loupe to see what they compare to.

[Mel Fulks]

Thanks David,I thought maybe you were actually cutting with slurry from a softer stone. The cabochons usually refer to any rounded polished stone without facets.

[David Weaver]

Thanks for clarification on what Cab is mel.

I do (I guess it goes without saying) have a bunch of slurry stones, from parts of stones to "real" tomonaguras, coticule bits, etc, but this is all straight from the diamond plate. Even a diamond plate doesn't raise slurry quickly, and I'm not sure if the slurry is full grit particles or if it may in fact be broken off bits of particles that were slashed off by the diamond hone.

The reason I'm gushing about the stone, though, is that for $10, it's literally all from the stone, slurry and all, and I'm kind of shocked to be able to take an old softer chisel that raises a wire edge with anything but the finest japanese natural stone and see no wire edge off of the jasper, and even with slurry, it might be sharper than any natural stone I've seen. Maybe not finer, but very keen. The stone would be a carver's delight, and the kind of stone I like to have by for sit-down joinery (like a long row of HBDT or something) where you can rub a good quality chisel on a very fine stone after each socket or two for 10 seconds and never go back to any stones (i.e., i never have to get off my butt).

For $10, though, it's really a treat for a stone fanatic.

[Shaun Mahood]

So David W, do you think you're up for the task of clearing up all of the questions about what the Spyderco stones are equivalent to? I would really be interested, as well as what happens to them when they are flattened as far as their sharpening characteristics go.

[David Weaver]

If you really scuff up the surface of a spyderco UF with a diamond hone (or if you use it when it's brand new), it is similar to a very fast 8000 grit stone. It's very abrasive. If you don't clean it and you just use some water to keep it from getting totally blocked up with some swarf (as in, you allow the surface to break in and do nothing about it) it becomes like glass, almost a burnisher. It's hard to say what it's equivalent to at that point, because it literally doesn't cut at that point and if you'd try to hone from a 1000 stone on it or something, it would frustrate you greatly. If you clean it with abrasive cleaner like it suggests, then it ends up somewhere between those two points (in fineness and speed) unless you really really get after it with abrasive cleaner.

Not sure about the medium yet, it's brand new so it's still aggressive. At this point, it's similar in speed to a slightly finer than 1000 grit ceramic waterstone (like shapton, bester, sigma power 1200, etc).

I think most people who are not used to natural stones (which also are constantly varying unless they're just plain soft) may get frustrated by the spydercos as they change their characteristics between freshenings.

That said, if you have a diamond hone and the UF is flat to it, you can keep it fast cutting pretty easily. I'd imagine the same is true of the medium, nothing can't be cut by a diamond hone, including the surfaces of the spydercos.

[Shaun Mahood]

The spydercos can definitely be frustrating if you expect them to stay the same. I've gotten into the habit of refreshing mine with a coarse diamond stone more often, and was playing around in the last few days with rubbing my UF stone together with my medium briefly between honings and that seemed to help both of them - though it may be the placebo effect working it's magic on me.

[David Weaver]

That doesn't sound like a bad idea, actually - rubbing them together.

[george wilson]

All I do with the white stone I have is let it polish the blade razor sharp. I very seldom bother scrubbing the gray deposit off of it.