How do you flatten Japanese Water Stones

[Ken Shoemaker]

A friend gave me a generous gift of two JWSs. They are 4000 and 8000 grit. I found that they are not even close to being flat by being dished in the center from frequent use. I have granat counter tops, so I have a flat place to work on it.

What should I do from here? Put 600 wet/dry down and try to flatten it that way???

Thanks in advance for your help.


Ken

[Patrick Tipton]

Use something courser - I have 80 grit on a granite cutoff. Water will hold the sandpaper to the granite. You are finished once the scratch pattern is uniform across the stone.

Regards, Patrick

[Wilbur Pan]

A coarse diamond plate of some sort is great for flattening waterstones. I have a video on how I do this here (http://giantcypress.net/post/668546073/japanese-tools-are-traditionally-sharpened-with), along with some other information about the diamond plate that I use. The whole process takes about 30 seconds or so.

[Dale Cruea]

I use 320 paper with water. Make lite pencil marks across the stones. When the marks are gone the stone is flat.
Coarse paper is OK but will grade the stone to wear a little faster I think. JMHO there.
You can flatten them dry if you like. Keep the paper clean as you go.

[David Weaver]

Ken, 180 or 220 grit wet and dry would be fine.

[Jim Matthews]

One of these (http://www.woodcraft.com/Product/2005775/17629/Flattening-Stone-With-Case.aspx) will do.

Get a drawer liner for the stones if you're not using a holder.
You're about to make a mess.

[Ken Shoemaker]

You guys are the BEST!!!! Tomorrow I'll post the results of the beating SWMBO inflicts when she finds out what I did on her countertops..... Maybe I can keep her at bay with a VERY sharp chisle.....NOT.

THank you all..... Ken

[Archie England]

My favorite is my iWood 300 that I bought from Stu @ Tools from Japan. This quickly flattens every stone, from a Shapton 120 to a Sigma 13000. I've encountered no issues thus far. I really prefer leaving the stone stationary and pushing the flattened over the stone. YMMV

[michael osadchuk]

I use sandpaper on marble or granite cast off floor tiles or kitchen backsplash, with the paper dry for ease of cleanup...... drywall screening sandpaper is the best I've found but all sandpaper works ... and yes, go coarser than you initially think so the chore is less tedious....

good luck

michael

[Stuart Tierney]

I use a diamond plate.

Use sandpaper at your own risk. Sure, many folks have used it with great success, but none of those folks have replaced a stone that was fouled up by sandpaper.

I have, and it wasn't my fault at all. I replaced the stone because I felt bad for the person who had the problem.

I won't do it again. Ever.

Use loose grit, use a diamond plate, use a flattening stone. If something goes wrong, I'll move heaven and earth to help you.

Use sandpaper, you're on your own. You should be ok with King and Norton stones, but anything else? Good luck with that.

Stu.

(Who takes money out of his own pocket that could be better spent on his 2 small children to make sure good quality diamond plates are readily and economically available. Yeah, it's that important and I feel that strongly about it. I've spent more this past month than most will ever spent on sharpening gear in their life to that effect, and been glad to do it.)

[Chris Griggs]

I used sandpaper when I was using nortons. It worked ok, but when I got a diamond plate I realized very quickly that the sandpaper was making my stone convex. Presumably because the paper wears faster in the center, so after the paper had worn down a bit, it was abrading the the edges of the stone face more than the center. I will never go back.

A diamond stones is an excellent investment, since water stones aren't something you flatten every once in a while. Ideally, you flatten the before, during,and after each use, and it is really worth it to have something effective quick and convenient.

[Patrick Tipton]

I use a diamond plate.

Use sandpaper at your own risk. Sure, many folks have used it with great success, but none of those folks have replaced a stone that was fouled up by sandpaper.

Hi Stuart - I am intrigued by how you could clog a stone with sandpaper? In my limited experience, the sandpaper doesn't shed any materially large grit. It takes about ten to twenty seconds of working my stones on course (I think it is 80 grit) sandpaper and the stones are flat and clean. The process definitely makes a slurry, but most of it looks like water stone and so I am guessing I am in effect using something far finer than 80 grit to flatten the stones. I have 4 water stones varying from about 1000 up to 10,000 and it seems to work OK on all of them. I've learned to do things incorrectly plenty of times, so it would not surprise me if this is a bad idea, I am just struggling to understand the mechanics.

Thanks!

Patrick

[Stuart Tierney]

Hi Patrick,

I've never used sandpaper, the stones I had when I was destitute were inherited, extremely hard and severely dished. Sandpaper didn't work at all, so I asked the local hardware store, they sold me a little bottle of loose grit at a great cost (spent my lunch money, and went hungry) and pointed to a kanaban, which I already had.

That worked reeeeeally well. Got the stones flat in a minute or so, and for a very long time that's all I used. I subsequently bought a larger bottle of coarse and fine grit as my finances allowed and got great mileage out of that.

Then I came into a little extra money, and got a cheapo diamond plate. That worked even better.

Now, I think I have a dozen or more diamond plates scattered around. Some are mine, some are in transit to new homes. I also have a couple dozen bottles of loose grit I send out with re-homed new stones that even diamond plates won't work well with (and will chew out sandpaper in seconds).

I have in that past asked a Naniwa and Shapton representative about flattening. They both said straight up that one should use loose grit (that they both make and sell for the purpose) or a diamond plate (which Shapton can supply at huge cost, but undoubted ability). I asked specifically about sandpaper.

Mr. Naniwa sucked air between his teeth, said he'd heard about it but couldn't condone it. Said contamination was a real risk because (I thought, since been confirmed and expanded) of the way the sandpaper works against the ceramic type stones and how it's put together. Apparently the adhesive can contaminate the stones (little evidence, but it does exist. I thought this was the sole reason) and the abrasive in the sandpaper can grab and embed in the stones since it's been ripped out of a fixed position.

Mr. Shapton said in no uncertain terms "that will void the warranty". Also explained in a clipped manner the same thing that Mr. Naniwa said, it can contaminate the stones.

I spoke to these two at an event at my local large home centre.

Since that time, I also asked Mr. Saito (Sigma Power president) over tea and cake here at home about how one should go about flattening stones, and he said either a flattening stone, loose grit or a diamond plate, and Sigma Power can provide all three. He also explained how they all worked and why they work. Loose grit tends to 'roll' and breaks the binder down without doing anything to the abrasive in the stone. Flattening stones are based on a much stronger binding agent than the stones they're meant to flatten, but are mostly the same stuff. These flatteners should break down slower, and they will abrade the stone's abrasive and binder, which is a different action to loose grit. Because these flattening stones are hard, any dislodged particles will start to roll and even if they gouge the sharpening stone, they won't likely embed (and are usually large and easily spotted). Diamond plates work in a similar manner to flattening stones, but the binder is much stronger and the abrasive in them (diamond!) is much harder. Diamond plates will abrade the stone and binder, but won't easily let go their own abrasive and if any is disloged, again it will roll and is not likely to embed in the stone.

Again, I asked about sandpaper. He laughed, saw I was serious and explained in detail what actually happens...

Unlike loose grit on steel or glass which rolls on a hard backing, flattening stones which are hard and durable or diamond plates which are also hard backed, there is give in the paper, which means that a loose abrasive particle can be pushed into the paper and stay there until it's either worn away or finds a spot in the stone where it can solidly embed, as the paper isn't tough or durable. That little particle stays in the stone, and you'll need to actively remove it (unless you get lucky and it dislodges by itself). At the same time, worn paper tends to have less well held abrasive particles, and you also expose an alien substance to the stone, the adhesive that holds the abrasive to the paper. I kind of wonder how much of an effect this will have, but apparently because it's soft it will embed into the stone, and can be worked into the stone so it stays there for longer than it might otherwise do. You'd need to aggressively remove a layer of stone to get it out. At the same time, I showed him on Norton and King instructions where they said "use sandpaper" and he explained that because these stones are softer, anything that does embed isn't going to be staying put for very long, and any adhesive is unlikely to adversely affect the stone because these stones are softer and small areas of inconsistency are only going to have a short term effect on sharpening. They'll either be missed (not felt) or will work themselves out quickly. On harder 'ceramic' type stones, any foreign matter is less likely to 'fall out' or be worked out without the user's knowledge.

This was mostly what I'd already thought, but he explained it completely and thoroughly without any shadow of a doubt. He'd also spoken to some people who had indeed experienced contamination issues and the general consensus is that it doesn't happen often and when it does happen it's more an annoyance than a game killer, but when your job is sharpening, anything that upsets your routine is frowned upon and there's no advantage at all to using sandpaper over and above loose grit/flattening stones/diamond plates.

All that without getting into the point of some stones might be flat when dry, but change shape when wet, so flattening should be done when the stone is in 'ready to work' condition, not dry and not after sharpening. Interestingly, the 'no soak' Shapton Professional series are notorious for changing shape when wet...

And that's it. I've known for a while that sandpaper wasn't such a hot idea, had it confirmed from two sources and fully confirmed from the last.

If you use sandpaper and you're happy and you get no trouble, great! I'm happy for you. If you run into trouble, then the above is the likely reason why you're having trouble.

And it's not like proper flattening stuff is prohibitively expensive. Some sandblasting grit and piece of old glass is just as good as a proper, pukka kanaban and brand name flattening grit. I give the stuff away (grit only) it's so cheap (actually King brand at the moment) and I sleep well doing it knowing that the loose grit will be used and will not cause any undue troubles.

Yeah, I use diamond plates. I can afford danged near any plate I wish and use what I think is best. I won't tell anyone they need to use the same plate I do unless they're specifically asking me what I use and why I use it, and even then there's no need to use a diamond plate, loose grit is fine.

This isn't something I've taken up as a crusade to wipe out the use of sandpaper to flatten stones, but the reality is that it's not a great idea and it's not recommended by the folks who make the stones or use the stones (except for King and Norton). There's a better way to do it, and in the end it's cheaper than using sandpaper.

And since you have a #10000 stone (which neither King or Norton make) you've likely voided the warranty as well. Yes, the folks who make the stones can tell, but don't worry. I've voided the warranty on all my Shapton stones (2 dozen?) already.

(But at least I can also tell them to pee up a rope as well. :) )

I don't really want to write this all out again, but invariably the subject will come up again and sandpaper will be 'highly recommended'.

At least I'm trying I suppose.

Now if you will excuse me, I'm seriously tired after a long day today rebuilding my computer amongst other things and yesterday was spent talking to a couple of chisel makers, saw makers and plane makers in between a 3 hour drive in a small car that's not ideal for highway work. In short, I'm dog tired and need to either do some work or even better, get some sleep.

Goodnight!

Stu.

[David Weaver]

Never heard anything about shapton pros warping, it certainly has never happened on mine and they get used in all manner of wetness, from dry 5 seconds prior to having had a wet surface on and off for hours. Maybe it has something to do with gluing the stones to backing wood, but I don't have any regular-use stones that aren't glued to a wooden base of some sort.

On the razor forums, I *think* some people have claimed that their superstones will move after flattening when they dry. I had a 12k superstone and it didn't happen with that one.

[Jack Curtis]

...I don't really want to write this all out again, but invariably the subject will come up again and sandpaper will be 'highly recommended'...

Don't blame you, so why not make this a page on your website and refer to it the next time?

Jack

[Patrick Tipton]

Stu - thank you for taking the time to write that out! Lots of work - that is a treatise, not a response and very generous of you to take the time to share your experience.

I am going to play with loose abrasives on my granite cutoff and see if I can tell any difference.

Regards, Patrick

[Stuart Tierney]

Don't blame you, so why not make this a page on your website and refer to it the next time?

Jack

Can't do that, commercial website and all that. Won't go down well here...

I'll do video sooner or later, makes it easier for folks to get their heads around, and I didn't drop a big chunk of change on all the video gear because I just wanted to. ;)


Patrick,

Put something on that granite first. If you use loose abrasive directly on the granite, it'll grind it down in very short order. Even thin glass is enough to protect the granite from being abraded away. Doesn't matter what the glass is, just so there's a layer. Could even use thin sheetmetal if you had to. The base doesn't need to be tool-room flat, just flat enough to get the stones flat. You'd be surprised how un-flat something can be that will still generate straight things. ;)

Stu.

[David Weaver]

You'd be surprised how un-flat something can be that will still generate straight things. ;)

Stu.

Ditto that on the flatness. I have used many different things to keep stones flat, and to be honest, as long as they are close to flat and not universally biased some way (like domed or extremely uniformly cupped), the stone always comes out very well - much better than it was before lapping.

My favorite cheap lapper is a $9.75 shipped 2 sided 6x2 inch diamond shim from ebay. let's just say the diamonds don't seem to be affixed to it quite as well as the DMTs and atomas, though.


The sheet metal is a good idea. Cheap and if it's soft enough, might be lucky enough to have some of that grit bite in.

[Stuart Tierney]

My favorite cheap lapper is a $9.75 shipped 2 sided 6x2 inch diamond shim from ebay. let's just say the diamonds don't seem to be affixed to it quite as well as the DMTs and atomas, though.


The sheet metal is a good idea. Cheap and if it's soft enough, might be lucky enough to have some of that grit bite in.

Copper or brass sheet? :)

Ally? Foil??? Got some camping foil that's really thick. Might give it a fang...

I had oodles of copper sheet, 0.5mm or so that would be ideal for diamond laps. Pity about the lead based paint on it all though...

Interestingly, the Atoma sheets are not that thick, but seriously rigid. They're just steel, and you'd think they'd flex and flop around but I've looked at mine and nothing doing. Stays flat, flat, flat and works well.

Only problem is, I need to work out something else to wean myself off Atoma.

Not that much of a problem, just an annoyance.

Stu.

[David Weaver]

sigma, iwood? How do those two hold up, similar to the DMTs? (Which hold up similar to the Atomas in my experience as far as stones go. just not as neatly made)

There have been a few "trend" plates popping up that look an *awful* lot like iwood, and they are sold here at an eye-popping price. They are nearly as much as a sintered plate.

Copper or brass sheet might be a bit pricey, but if it's laying around! Assuming that lot of the folks over there who use loose grit are just using it on the steel kanaban? Seems like a good way to go. Cheap, the right hardness, reflattenable and strong (just not always that flat when they're new).

I haven't heard yet of anyone wearing out a decent diamond hone on stones, as long as they're used only for stones. Makes it hard to suggest anything other than them for flattening stones.

[Frank Drew]

I do it the way I've seen Japanese carpenters flatten their stones: First, flatten the coarse stone on a cement block with some fine sand and water (play sand is ideal), rinsing well when done. This flattens the stone quite nicely; it leaves a slightly rough finish but that evens out with your next step, which is to flatten the finer stone with the coarser stone, using water as a lubricant. Again, rinse well afterwards to make sure there's no stray sand or other grit on your stones.

Done and done, two stones flat in about five minutes.

[Stuart Tierney]

I do it the way I've seen Japanese carpenters flatten their stones:

Done and done, two stones flat in about five minutes.


So do I...

You know, I've heard about the concrete block/sand thing, but I've never actually seen it.

What I have seen are Atoma, iWood (the two most common, popular and with solid reputations*) and similar diamond plates. I've seen loose grit on kanaban, flattening plates and glass, I've (twice) seen bare concrete then another stone to clean up the mess, I've seen them eyeballed flat with a nagura, I've seen flattening stones, I've seen a coarse stone used then another stone to clean it up.

(* never actually seen a Shapton diamond doohickey being used outside a tool show where official Shapton representation was present.)

But I've still never actually seen loose sand on concrete. I don't actually expect I ever will.

Here's why.

Most carpenters will be working on site or in a workshop. On site, they don't own the concrete, and it'll likely leave a tell tale mark of some kind which would be unsightly and considered 'uncouth'. In a workshop, there's only so much usable concrete around, and it's only so flat. There are likely others in the workshop, and peer pressure wouldn't allow one to let a stone get so far out of whack that it needed such radical and obvious flattening (rubbing a stone on a handy wall or floor is difficult to disguise!) since the innuendo from your fellow workers at being so poor a sharpener would be unbearable. A compact, easy to tuck away and no-evidence-leaving method would be best and nobody would say anything about it even if they saw it being used. No evidence, no crime.

(Japanese culture tends to make outside influences very important. Westerners might not care what anyone else thinks, Japanese care VERY much what everyone else thinks.)

Now, I'm not saying it doesn't happen somewhere, but I've never actually seen it. Perhaps it's a method that's since gone out of favour, perhaps it was a quick and dirty thing used when there was nothing else available, but I've still never seen a stone flattened with sand on concrete.

(Fun fact, most folks who I consider to be 'good' at their trade tend to go with the diamond plates. Next to no fooling around, fast and they always, always work. Sorry to burst anyone's bubble there, but that's the truth. I don't know if I got pictures of it or not. Next year, shouldn't be an issue to get pictures of all kinds of stuff since the national kezuroukai (planing festival, google it) is a scant hundred or so km away. Might even throw my hat in there. :) )

Oh yeah, concrete blocks here tend to be pretty crap to be honest. Beach sand, shells included and concrete. They tend to fall apart at the slightest provocation. Go on, ask me how I know that.

Stu, who's spent 10 minutes picking seashells out of his elbows more than once...:mad:

[Jack Curtis]

I've cleaned coarse stones on my sidewalk, and coincidentally flattened them, all the way around. No lasting nasty marks were left. I don't know if anyone saw me or not. :)

Jack

[Rob Fisher]

...Oh yeah, concrete blocks here tend to be pretty crap to be honest. Beach sand, shells included and concrete. They tend to fall apart at the slightest provocation. Go on, ask me how I know that.Stu, who's spent 10 minutes picking seashells out of his elbows more than once...:mad:Ok, I'll bite. Do tell.

[Charles McKinley]

I use a concrete block also

[Frank Drew]

Stuart,

My experience working with several Japanese carpenters (meticulous and highly skilled craftsmen) is from the early Eighties, before diamond plates became widely available (I never saw them back then, at any rate.) You'll note from my post that I said they used a concrete block (sometimes called a cinder block here in the States), not a section of concrete sidewalk. I worked with them on a residential job and there were no sidewalks anywhere nearby, but there were plenty of concrete blocks (and our blocks here are well made and quite flat). And, as I mentioned, this method works very well, certainly in the absence of diamond plates or other sharpening adjuncts.