How often to flatten ceramic water stones

[Tony Wilkins]

Actually the new Suehiro Dual Stones I got from Stu today. They're great and got here really fast (thanks Stu). There's only one question I have in using them. Coming from a king stone 6,000 grit and a generic red 1000 grit (Hida), these are the first ceramic stones I've had. They are 'dish resistant' so I'm not sure how often to take my diamond lapping plate to them compared to my other stones. Anybody have a suggestion?

Emailed Stu so when I get a definitive answer I'll post back, but wondering in the mean time.

TIA,
Tony

[Adam Cruea]

Take a straightedge and place it from one corner to the other. See if you can see light under it, or use some feeler steel.

After a while of having them, you'll start to get a feel for how long you can go between flattenings.

You can also just do what I do. . .use a flat diamond plate to flatten them, and when you suspect they're dished, mark stripes across them with a pencil and start to flatten them. If the entire pencil mark gets worn off right away, they're still flat. If not, they needed flattened.

[Derek Cohen]

Hi Tony

It is not just about keeping stones flat, but a swipe with a diamond stone also keeps them "fresh" and they cut faster as a result.

Compared to a 6000 King, which you would need to flatten each blade, you could get away on a Sigma with several blades - but why would one? The stone would load up (even with soapy water). Note: the flatness of a 6000 stone, even a King, is not really that important, unless you are polishing the back of a blade. It removes so little metal. So don't sweat it. A 1000, on the other hand, is another story - keep that one as flat as can be!

Regards from Perth

Derek

[Federico Mena Quintero]

Think of the length of the surface you are honing vs. the curvature of a not-perfectly flat stone. E.g. a plane iron bevel may be 5 mm long (the bevel itself, not the width of the iron). If your stone is curved lengthwise, then you can probably hone with the iron perpendicular to the long axis of the stone, and you'll be fine. But you wouldn't be able to hone parallel to the long axis unless you wanted a camber corresponding to the curvature of the stone.

(Conversely, if the stone is curved width-wise, you'll get a camber if you hone perpendicular to the long axis of the stone.)

(And if the stone is dished in both axes, it's pretty hard to hone a wide iron accurately - maybe a narrow chisel, but not a wide one.)

If you are honing/lapping the back of your iron or a chisel, then you really want a flat surface, or you'd be putting a back bevel on your iron.

Summary: consider the orientation of the iron or bevel with respect to the curvature of the surface. If unsure, keep the stone flat.

With a bit of practice, you can actually feel when a stone is getting too curved for accurate honing. I don't keep my stones flatter than necessary, and they work fine.

[Stuart Tierney]

I've emailed back, but here it is for everyone else to see.

The stones you have are not the same as what most folks here know as 'ceramic' stones and won't need much flattening at all. Cleaning and conditioning yes, but flattening, no.

The trade off is they're not as fast as regular ceramic type stones, but they're not too bad.

Check them occasionally, but keep in mind the main similarities between these stones and usual ceramic stones are that they're made of essentially the same stuff, and that's it.

Good luck,

Stu.

[Chris Griggs]

Stu, are these stones more like the Spydercos?

Also, given their hardness are the standard diamond plates (atoma or iwood) the thing to use for conditioning? If not what is your recommendation for this.

EDIT: I see they come with a conditioning stone. Perhaps this is the answer to my above question?

One more thing. Are they flat when new? If not, how hard are they to flatten?

EDIT 2: Oh my gosh these are interesting. What about the diamond stones of the same line. I get the impression that you are listing them more as coarse to medium steps in the honing process as opposed to for flattening stones. Are they mono or polycrystalline? And what is the recommended "line-up" for this line for day to day honing. Given that they work much finer than their grit implies I would imagine its something like 1.2k diamond - 1k stone - 6k or 8k stone OR would the 6k have the power to go straight from the 1.2K diamond? And how fine are the 6k/8k capable of going, and to what extent can they cut/remove scratches from previous grits?

Sorry for the highjack Tony. These are intriguing though (not that I need any new stones).

[Tony Wilkins]

No problem Chris. My question's been answered and part of the reason I asked was because I thought they were pretty cool. As to the 'conditioning stone', it more of an eraser than a stone. That's the only one of your questions I feel qualified to answer though.

[Stuart Tierney]

Chris,

I think it likely they're similar to the Spyderco stones, although from what I've heard (not tried) with the Spyderco stones, these Dual Stones are not quite as hard, and for that, are a little more effective/faster.

They'll yield to diamond plates, no problem. Well, not 'no problem' as they're HARD, but I used the diamond plate included with the little drum-box Tony bought, and it worked nicely. The associated diamond plates are, I think, mono-crystaline and I've got some questions about them so maybe I'll find out then. Suehiro and I communicate quite a lot, and they're very free and willing with information when we ask. Either way, I've used the diamond plates with a little steel and initially they hold up as well as (or better) than the Atoma and iWood. They don't seem to have lost anything from new.

The diamond plates are intended to be used for fixing blades, and as such have well held diamonds. I suggested to Suehiro that they could also be used to flatten the stones and they had no problem with that idea, although I don't think they planned to suggest that.

The key difference I can tell is that these Dual Stones will tend to bite into very hard and wear resistant steels a LOT better than they rightly should.

Case in point, I have a PM-HSS blade I use for testing and occasional use. It's super hard, and my otherwise lovely Black Arkansas stone (which will deliver a killer edge easily) will hardly mark the blade. The Dual Stone 6K starts making swarf after a short time, and yet, the edge I can get from the 6K DS is not lacking compared to the black Arky when the black is working well. Not universal praise, as I think the black Arky can probably give a better edge outright, but in most cases, the 6K DS is favourably comparable to the black Arky. My translucent isn't half as good as the black, so no comment there.

I think the 6K, so long as you work a minimum of steel, will take over from a 1K stone without too much trouble. It's not going to work a full bevel on anything because hard steel will take too long and softer steel with overload/clog it. Remember that I tend to look on things as "will anyone be able to replicate these results", not by using any number of tricks and 'techniques' to coax better performance from anything. I think that if you got in the habit of using a little slurry, they'd be rather rapid when you wanted them to be, and then wash off the slurry when it came time to finish up and they'll do that too.

The few that I've seen are flat and ready to use out of the box. Suehiro tend to be very good about this, and I've yet to see a stone from them that wasn't very well prepared as it came out of the box (we inspect them all before they go out). Maybe a few lines, but generally flat and ready to go.

If there is a stone they can be compared to, it would be the Spyderco stones, but I think the DS are a little more flexible in how they can be used and a little more effective, without giving up much in terms of maintenance (dishing, etc.)

I'm like you, I need another stone like another hole in my head, and I lust after no stones any more.

But that #1800 is very, very tempting. Stupidly so, since I could just ask for one and they'd probably give me one to test...

Really, these stones are supposed to be for knives and used in kitchens, where folks might tend to be slightly more 'abusive' to their stones with harsh cleansers and oils flying about. Take a licking and keep on ticking kind of stones, and for that, they'll be pretty good if a little 'alien' to what most folks expect from a Japanese stone.

I don't think they're for everyone, but some folks who have a desire to avoid the 'mess' of waterstones, but want some of that kind of performance might like them. I don't know. Suehiro kind of sprung them on us, and didn't ask us anything before they started sending information brochures about them a few months ago.

(Here's something I think of occasionally about these things. These DS deliver the long life, low dishing that the Shapton Glass Stones promised. That they are so vastly different to a Glass Stone (GS are much faster) tells you how 'wrong' that promise was.)

I hope it helps, and isn't too preachy. These DS are not bad, but they're not what folks expect them to be even though they're 'ceramic' stones. Your bathroom tiles are 'ceramic' too you know...

Stu.

[Chris Griggs]

Thanks Stu and Tony. That's helpful info definitely covers what I was wondering. Interesting stones. I like that they come in small sizes too. I quite like smallish stones.

So what's the deal with the 1800? I see its labeled as "superior". Hows it different from the the rest of the line?

Thanks again Stu...always appreciate your detailed responses and the fact that you are willing to discuss both the pluses and the warts of the stuff you sell.

(BTW: what is the micron rating on my ceramic bathroom tiles )

[Joey Naeger]

Dang, those look interesting. I like the spydercos a lot, but the option of more grits appeals to me.