Tell me about the Naniwa Chosera water stones

[Mike Brady]

I have a new Chosera 10,000 grit stone. It is the only non-Norton Water stone that I have, and it has a much different feel than the Nortons. Norton graduate nicely from grit to grit. In my case 1000-4000-8000. The Chosera has a very hard, sticky feeling, particularly when swarf starts building up. Water does not wash this swarf away. Smaller blades, like chisels, can be hard to stoke on the stone. I should add that I sharpen using an Eclipse guide on everything. The 10,000 grit polish is like a mirror and the blade is very sharp afterwards. It also stays flat for a very long time. Plane irons clamped in a jig present no problem since I am honing just a thin secondary bevel and a firm two-handed grip overcomes any stickiness from the stone.

There are a several people on this forum who have extensive knowledge and experience with Japanese stones. I would appreciate their feedback and suggestions about maximizing my results from this stone.

[Chris Griggs]

I'm sure you'll want Dave, Stu, and Archie to respond.

I haven't used the 10k, but have used the 1k and the 400. I would describe the 1k similar to the way you describe the 10k. Number one thing I found with the 1k is to really back off the pressure. These cut fast with a light touch, and with lighter pressure the 1k anyway is smoother to use. Some stones also have a breaking in period. The very outer layer is a bit harder then the inside and they get nicer as you use them - I'm not sure if this is true of the Chosera though, Stu will know though.

Archie uses his 1k Cho a lot and has had similar issues with it loading. When the stone first starts to load he will actually break up the swarf with a paper towel - he says that once he does that once the stone stops loading for the remainder of the sharpening session. I have no idea why this works for him, but he swears by it.

[David Weaver]

It is (the 10k), to me, the best polishing artificial waterstone available for woodworking. It's blindingly fast for the fineness, and puts on an edge as good as any artificial waterstone I've tried with less effort than any artificial waterstone I've tried. (Much less effort than a natural stone, too, just comparing apples to apples with the man made stones). Under a scope, the shapton 30k is probably finer, but for practicality, it's not worth worrying about.

The choseras are all different, though, so whatever is said about the 10k can't necessarily be said about the 5k, etc, apparently. I have the 3k and the 400, and they are miles different than the 10k, and I understand the 1k between there to be softer than those (both the 3k and the 400 are very hard).

With a soak, the chosera is better by a good bit than it is if you just spritz it, but if you have it in the shop and you spritz it off and on during your session, the top gets the soaked feel, anyway. The flushing of the swarf is better soaked, and the feel is smoother - it's a very freehander friendly stone that I would call middle of the road hardness (softer than shapton pros by a fair amount but quite a bit harder than most of the soft stones).

I am very partial to the shaptons because they have been my go-tos for so long, and I like the stones of stus (the sigma powers) that I've tried. They are both better dollar for dollar for someone who doesn't have the resources (as long as the shaptons are bought foreign or second hand), but if you aren't completely sold on the chosera being the best, just use it for a little while and get comfortable with it.

[David Weaver]

There's another dirty secret out there. A magnesia binder stone, like the 10k chosera if i'm not mistaken, is out there that fujibato (330 mate) carries. He sells them one at a time on ebay for about $38 shipped on ebay. (i have no affiliation to him)

They feel not a lot different than the 10k chosera if you keep the surface on both clean, though they are a 6k stone and not as keen as the chosera. They are also no-soak stones, soaking would damage them, but a lovely little secret stone.

I had a conversation with stu not long ago and he will be carrying them soon, but I wouldn't expect he'll be able to match fujibato's price on ebay because fujibato seems to use ebay to dump items and his store prices are much higher (i.e, nobody could sustain a legitimate business with some of the prices he charges for things when he's dumping).

And overall, none of this is to suggest that anyone who is using any decent set of stones of any type will gain much or anything in their woodworking by buying $265 finish stones or ordering stuff from overseas on ebay - it's an issue of relative comparison for comparison's sake. Sort of like how some folks drive 400 horsepower mid-sized cars and adhere to speed limits. To a person from the outside who is just looking to get from point A to B, it makes no sense.

[Archie England]

I have a new Chosera 10,000 grit stone. It is the only non-Norton Water stone that I have, and it has a much different feel than the Nortons. Norton graduate nicely from grit to grit. In my case 1000-4000-8000. The Chosera has a very hard, sticky feeling, particularly when swarf starts building up. Water does not wash this swarf away. Smaller blades, like chisels, can be hard to stoke on the stone. I should add that I sharpen using an Eclipse guide on everything. The 10,000 grit polish is like a mirror and the blade is very sharp afterwards. It also stays flat for a very long time. Plane irons clamped in a jig present no problem since I am honing just a thin secondary bevel and a firm two-handed grip overcomes any stickiness from the stone.

There are a several people on this forum who have extensive knowledge and experience with Japanese stones. I would appreciate their feedback and suggestions about maximizing my results from this stone.

The Chosera 1k is great stone--once you learn to manage it's initial tendency to load up!!! As Chris said, I've found the light touch to be the best approach. Second, once I see heavy swarf glazing over my path, I add a tiny spritz of water, a few circular strokes, and then wipe the stone face clean. Add another spritz, and the stone will amazingly work up a small slurry that will not tend to load or glaze ... so long as you work lightly. Heavy stroke action will really load the stone up. This, IMO, is the genuine weakness of the Naniwa Chosera 1000. However, it's benefits are numerous: highly dish resistant, long lasting!!!!!, firm enough to start out with push strokes, and it cuts all my O1 and A2 like a speedy bandit. Also, until I learned to break up the glazing, I didn't get very polished backs and bevels, it left a matte finish. Now that I've learned to clean off that initial glazing (again, which you must break up first), I get highly polished edges (backs and bevels). The best benefit for me freehand sharpening on the Chosera 1k is this, it's genuinely hard enough not to dub over my full bevel sharpening (I still don't mess with secondary bevels). The same goes for the Chosera 3k, which is an even better stone than the 1k. Though it somewhat wants to load up, it's real easy to keep the swarf/slurry moving and working for me.

Now, I'd be remiss not to mention my favorite 1k, the Sigma Power ceramic 1000. What a fantastic total package of a cutting, honing, and polishing stone. The Sigma just never loads up, doesn't demand special techniques, and yet yields a truly sharp cutting edge. Though I can put either the Chosera or Sigma 1k edge on a Sigma power 6k, both genuinely benefit from an intermediate step stone. Again, this is not necessary; but it really does improve the final edge coming off the 6000 stone.

Congratulations on the Chosera! It's a workhorse, with needs. Lighten up, make circular motions while adding a small bit of water, and all will turn out well! BTW, I do hate the green goop. This never goes away, but it does lessen a little once you've broken in the stone.

[Stuart Tierney]

Soak it. For 5-10 minutes. No more, no less.

If I can do nothing else on this planet before I shed my mortal coil, it'll be to convince folks that "soaking the ^%$^%$^*% stone!!!" is not the terrible, nasty, evil and to-be-avoided-at-all-costs activity that too many purveyors of sharpening stones make it out to be.

If the stone needs the water in it (or is otherwise improved by soaking), then all you're doing by not giving it that water is hamstringing it to a point where you might as well use a rock you found outside.

With regard to the Chosera, soak it for 5-10 minutes and see what happens. No more than that, you can permanently damage the stone. Let it dry slowly, no heat or breeze blowing over it, you can permanently damage the stone. No chemicals in it (soap, bleach, etc.), you can permanently damage the stone. They're notoriously fragile and when they're not happy they're pigs of things to use. But when they're right, they're seriously good.

That they're still popular with the sky-high price tag, you'd expect them to be spectacular, and they are.

Soak it, I hope I'm making this perfectly clear here.

And good luck.

Stu.

[David Weaver]

I think the chos say 20-40 minutes on the side of the stones, but they say it in japanese, so I couldn't read it if I tried. I usually soak mine for about 20 minutes if I do soak them. But I use them enough that the surface is wet often when I use them. They will craze if you try to rush their drying, but if it's minor crazing, it won't affect their use. I don't baby mine too much. They're worth the effort.

I'd say the difference between not soaking them and soaking them is along the lines of their behavior being like a shapton when not soaked well enough. When they have been soaked, they don't glaze and their action doesn't change in use - they feel like a good medium hard suita or tomae stone, except maybe without quirks that some naturals have. When not soaked, they still have a bit of an artificial feeling (well, they are artificial, so I guess that's allowed). The same effect as soaking can be had by just splashing water on them a few times, and then the whole stone is not wet all the way through.

[Jason Coen]

Sorry if this is a hijack, but could someone compare the Cho 10k to a glass Shapton 16k so I can have some frame of reference? The Shapton had an unfortunate meeting with the floor and is no longer in one piece , so I'm searching for a new finishing stone. I've got 1k, 4k, and 8k glass stones and might take this opportunity to tweak the line-up just a bit.

[David Weaver]

It is at least as fine or finer (at least the edge resulting is, not sure on the abrasive size on the chosera), the polish is better, and it's faster than the shapton glasstone, and at least as fast as a very freshly lapped 15k pro (which is only that screaming fast right after being refreshed).

And the abrasive is 5 times as thick.

No stone is going to regularly survive a drop to the floor, though, unless someone starts making rubberized abrasive sharpening stones.

Well, I have a diamond hone that has survived the fall to a concrete floor, but the dented up corner had to be filed off.

If and when you use up that 1k stone, replace it with a pro stone instead - it'll last much longer.

You could also add sigma power's 13k stone after the 8k glass stone. That's an easy jump, and it's as fine as the chosera, just not quite as fast and not quite as hard and releases a bit of slurry. Probably about half the price, too and overall, to me, a nicer stone than the glasstones for little more than the 16k costs.

[Jason Coen]

Many thanks, David, that's exactly the kind of info I was looking for.

I got the 1k, 4k, and 8k as a gift, and added the 16k when I found a screaming deal on it. I've had the 1/4/8 for about a year, and the 1k is already about 1/2 gone. Definitely not going the glass stone route again for the 1k. I've been generally pleased with the them, but coming from a set of Norton's I don't have a huge wealth of experience with which to judge their performance. I did like that they were more user friendly than the Norton's, but as I've gotten more use out of them their ease of use appeal has dwindled a bit. Or, rather, as sharpening has become an almost daily occurrence, a soaker stone or softer stone is not the impediment that it once seemed to be.

The Sigma Power stones are intriguing. As I sharpen much more frequently now, I'd really like a faster stone than the glass stones (it helps too that I better know what to look for when sharpening and am not as worried about continuing to sharpen on a dished stone, etc.).

Again, thanks.

[Mike Brady]

Thanks to you all. Soaking is where I need to begin (literally). I was shortening that soak time considerably. If I have any more questions, I'll be back!

By the way, I was talking with a tool maker who literally has hundreds of hours experience with Shapton (glass)stones. He has switched to Choseras and finds them to be superb. It was actually his recommendation that prompted me to get the 10,000 grit. I should have spent more time finding out about the use of the stone. He had mentioned the "stickiness" but I didn't pay enough attention to what he said was causing it.

[Rick Fisher]

TFFW has a Niniwa stone that is 12000 grit but only 10mm thick .. would it be basically the same idea as the one described by the OP but a touch finer ?

I read an article, I think written by Stu about the actual microns on each mfg stones and how an 8000 from one MFG may be coarser or finer than an 8000 from another ..

TFFW suggests only spritzing the 12000 grit super stone because its resin based..

[David Weaver]

The superstones are softer (the 12k you're describing). They are good stones, but not quite in the class of the choseras, and the harder the steel, the more evident it becomes.

[David Weaver]

Jason - the glasstones are good stones. Easy to get results from. My complaint with them (i've used the 1, 16 and 30 enough to know what they're like) is that shapton shorts the buyer on abrasive. It doesn't matter so much on the finer stones, they'll last for years. I think the 1k is too soft compared to the rest, but if it's not my imagination and it is actually softer, I understand why they made it that way. Just a bad combination to make it both softer and very thin.

For practical purposes, if the stone hadn't met the floor, I would not replace a 16k glasstone with anything - all of the hard stones are not that far apart in performance, and all are extremely easy to get an incredible edge from.

The SP 13k, chosera, glasstone 16k, superstone 12k, and shapton pro 15k are all similar in the edge that's produced. Where they stand apart is when you do a test that nobody would do with real tools, which is to do something like the article that FWW just released on their digital site - to sharpen full bevel on hard a2 steel with 1k stone through polish stones.

Anyone who has the online subscription can go see the FWW article, I guess it's not out in a magazine yet. Stu's stones did well, as did the shaptons and choseras - not much of a surprise those three are at the top of the list.

[Jason Coen]

Jason - the glasstones are good stones. Easy to get results from. My complaint with them (i've used the 1, 16 and 30 enough to know what they're like) is that shapton shorts the buyer on abrasive. It doesn't matter so much on the finer stones, they'll last for years. I think the 1k is too soft compared to the rest, but if it's not my imagination and it is actually softer, I understand why they made it that way. Just a bad combination to make it both softer and very thin.

While I don't have much experience across a variety of stones, the difference in hardness between the Shapton GS 1k and the GS 4k/8k/16k seems much greater than the difference in hardness between my previous Norton stones of equivalent grits. I can't say if this is normal or not, but it is something that I also definitely noticed. Did Shapton go this route on purpose in order to make the stone a little faster since more "work" is done on the 1k stone as compared to the finer stones?

For practical purposes, if the stone hadn't met the floor, I would not replace a 16k glasstone with anything - all of the hard stones are not that far apart in performance, and all are extremely easy to get an incredible edge from.

I was pretty disappointed when it happened, though I managed to not yell at the goofy lab that precipitated the stone's unfortunate meeting with the floor. I really liked the 16k (also pleased with the 4k and 8k - I actually think the 4k stone is my favorite of the bunch).

In any case, I like what I've read about the Cho 10k and Sigma Power 13k stones. I'm at the point that I feel pretty comfortable buying an expensive stone like the Cho since I intend to use it until it's consumed (barring any more incidents with the dog, of course), but at the same time don't want to throw dollars at something that's "better" while providing no discernible advantage when steel meets wood.

How does the 1k Select II stack up against a SP ceramic 1k? Would either "play nice" with the 4k/8k glass stones? My 1k GS isn't long for the world, and I may as well have its replacement in hand.