How do you guys flatten waterstones?

[ScoFF]

I just ditched my worksharp in favour for waterstones for sharpening plane blades after investing in a recent Veritas plane event, I figure I'll throw myself in there and sink or swim.

I got 3 Bester waterstones, 700, 2000, 8000. Sooner or later they'll be unflat if that's a real word. How should I flatten?

I've seen people use Norton drywall sanding screen on glass or mable on the low grit, then flatten the other stones off each other low to high. I have two quesitons, what sanding screen grit should I use and is this a good idea?

[jpdorn]

i use the atoma 400 purchased from stu at http://toolsfromjapan.com/.

i've used dmt diamond plates, sand paper on a granite surface plate, and the norton flattening stone. the atoma rules them all in my experience.

grats on the new stones. that'll be fun.

[wilburpan]

I also use the Atoma 400 grit diamond stone. It's great.

Flattening a waterstone is a part of life. Using the Atoma makes it easy and quick enough that it's not annoying. All the other methods I've tried were annoying, including using a sanding screen and sandpaper on a granite plate. As a result, I would flatten my waterstones less, so I would get poorer sharpening results. With the Atoma diamond plate, it's easy to flatten the waterstone, so I keep up on it more, so my sharpening results get better.

Here's a short video of how I do this. http://giantcypress....-sharpened-with

[ChrisG]

I use an iWood 300 diamond plate - also from toolsfromjapan - Works great. You really want to flatten your stones quickly before each use as opposed to waiting until they are noticeably out of flat so it pays to have something quick and easy. Get a diamond plate - really it's worth it.

[Ed Waite]

Waterstones don't usually come very flat, so you may want to figure out a way to flatten them right away. Check them with a straightedge while they are dry before use.

If you have some float glass or marble that is really flat, you can use 220 grit wet/dry sandpaper. David Charlesworth uses this and has an excellent video on sharpening. His methodical approach is bulletproof or idiot proof although some think it's a bit tedious.

A lot of very good information on sharpening can be gleaned from the knife gurus and their forums. They are way into sharpening and often use many many different waterstones. I've read that much of that info has trickled down to woodworkers over the years.

I read on one of the knife forums that some have had problems with the Atoma slightly rusting if you don't dry it well. One user detailed a procedure where he sealed the edges with silicone I think to prevent water from getting to the metal plate. Other than that, the Atoma seems very good and durable and highly recommended.

I've been using a coarse/very coarse 10" DMT Duo Sharp for a while now and it works fine. It can also pull double duty for other sharpening tasks. I don't use it on very coarse stones though. I use sandpaper on a granite surface plate for regrinding a primary bevel and other coarse tasks.

I think I will buy the new DMT Dia-Flat soon. It got a good write up from Chris Schwarz a while back. It's flat to .0005" I think it's worth looking into. It doesn't come with a list of "no-nos" and things you shouldn't use it on, like most other lapping plates. Some of the popular very hard and very coarse stones below 150 grit seem to chew up lapping plates. The youtube movie from DMT implies you can use it on anything. If I buy a lapping plate, it will be an Atoma or the Dia-Flat.

2 cents, bah. There's a nickel's worth for my 1st post. Good luck.

[wilburpan]

I think I will buy the new DMT Dia-Flat soon. It got a good write up from Chris Schwarz a while back. It's flat to .0005" I think it's worth looking into. It doesn't come with a list of "no-nos" and things you shouldn't use it on, like most other lapping plates. Some of the popular very hard and very coarse stones below 150 grit seem to chew up lapping plates. The youtube movie from DMT implies you can use it on anything. If I buy a lapping plate, it will be an Atoma or the Dia-Flat.

I've used the Atoma 400 grit and the DMT Diasharp diamond plates for flattening waterstones. The big advantage that the Atoma has is that the plate has grooves in it that give the water and sharpening stone grit a place to go. The DMT stones are a big flat surface. What happens with the DMT stones is that as the waterstone becomes flatter, surface tension causes the DMT stone to stick to the waterstone, which is annoying.

I also find that the Atoma plate is holding up better with time than my DMT Diasharp.

I've seen the Dia-Flat, although I haven't used it for waterstone flattening. From looking at the Dia-Flat, the only difference between it and the Diasharp is that the Dia-Flat is certified to a degree of flatness, which probably explains why it costs more. It has a very coarse grit, but none of the grooves that the Atoma has. The Atoma has not had any reported out-of-flat issues, and mine is certainly flat enough to give me excellent results.

[Joraft]

I have the Dia-Flat and think it's worth every penny. It is the best lapping plate I've ever used.

[ScoFF]

How do these diamond plates work, do you spritz some water on them and rub your stone on them if do it dry?

Do they themselves go out of flat? Wear out? I notice the Atoma plate has an accessory called 'replaceable diamond sheet'. I thought this was a diamond stone, not a sheet put on top of a hard surface. How long should I expect a $100 diamond plate/sheet to last? This stone sharpening is expensive!

[Onboard]

What is the consensus on Shapton Glass Diamond Lapping Plate for flattening water stones? Oh, and please ignore the price! http://www.woodtalkonline.com/uploads/emoticons/default_sad.png' alt=':('> On the webpage they do have a Shapton FAQ, which is a good read, and includes a section on flattening water stones.

[Ed Waite]

Wilbur, the Dia-Flat is different from the Diasharp even though they look similar. It has a different coating that is supposed to be more durable. I haven't heard about any flatness or dishing problems with the Atoma, that's why I would consider it as my next lapping plate. A couple people were worried that the rust issue may cause pitting that would affect the flatness, but that was an old thread that I read like a year ago maybe. I would just replace the sheet on the aluminum plate if that happened. It does get abraded though and seems to lose its grit on the really coarse stones, but all lapping plates lose to the really hard and or coarse stones. Not sure if there's been enough time to test the Dia-Flat. Schwarz was told to abuse it and he said he lets anyone use it to flatten their stones. This was before he switch back to Arkansas stones.

Bob, the sheet is something you can replace when you notice that the Atoma is taking longer to sharpen or flatten your stones. You probably would never have to replace that sheet if you used most 1000 grit or higher synthetic stones.

Onboard, Schwarz said he motored through a bunch of the Shapton lapping plates. At a recent hand tool event, a guy from the company said they went through a number of them also. It still may be worth it to some though. The Shapton glass stones are well liked and 30,000 grit may keep an edge slightly longer some say.

[jwatson]

i use drywall sanding screen

[Ed Waite]

Oops, sorry Bob I missed the rest of your question.

How do these diamond plates work, do you spritz some water on them and rub your stone on them if do it dry?

Do they themselves go out of flat? Wear out? I notice the Atoma plate has an accessory called 'replaceable diamond sheet'. I thought this was a diamond stone, not a sheet put on top of a hard surface. How long should I expect a $100 diamond plate/sheet to last? This stone sharpening is expensive!

I rub the Duo-Sharp on the stone while the stone is on its holder. The 1000 grit is always wet. I just dunk or spritz the 8000. Read the directions for your Besters. Some stones shouldn't be kept in water for very long and others can be left in water. Some just need a spritz. It sometimes varies by grit. Yes, plates can go out of flat. Most will wear over time depending on the stones and if you use the plate to shape hard metal. The good ones just wear and stay flat, they may just take a little longer to do the job.

[Onboard]

Here’s a video (about 2 1/2 minutes) on how to keep you sharpening stones flat while sharpening. It’s about oil stones, but it seems that it may work for other types sharpening stones as well.

Here’s an excerpt about this video: “Carpenter and woodworker Carl Bilderback never flattens his oilstones.”

[mikem]

I actually use a lower grit sand paper on top of a granite block. This is inexpensive and gets the stone very flat.

[jpdorn]

i feel uniquely qualified to address the dmt vs atoma issues with regards to rust. my sharpening station is about 6' away from a little over 600gallons of salt water which is continually atomized via a large protein skimmer. here is a pic of the two which have spent the same amount of time in this environment.

this isn't entirely fair because i grind tools on the dmt and use the atoma only for stone flattening. i'm sure i've left swarf on the dmt and it encouraged the rust. it's never bothered me and i don't see why it should. my point is only that the atoma resists rust just fine.

[CessnaPilotBarry]

Just like sharpening, I've found that flattening my waterstones often is fast and easy. We're talking seconds, and just a few strokes. Wait longer, and it takes far more time to remove far more stone.

Technique matters, too... Use the stones as evenly as possible, spreading the wear.

Oilstones are not the same animal as waterstones, don't compare them when discussing flattening.

[ChrisG]

The following was posted to another forum last week regarding the same question - I literally copied and pasted it. The poster was Stu Tierney, owner of toolsfromjapan.com - I consider him to be an authority on synthetic Japanese water stones - modern ceramics in particular. The basic gist is that flattening on sandpaper is fine (though not ideal) on kings and nortons, but that it is a bad idea on ceramic water stones and can potentially damage the stone.

"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."

[ScoFF]

Thaks for all the responses, any thoughts on using a plate (or other flattening method) on the lowest grit stone but then using that stone to flatten the next highest grit stone and so on?

Ex. diamond plate to flatten the 700, use the flattened 700 to flatten the 4000, then the 4000 to flatten the 8000 ?

How long should I expect a flattening plate to last given that I'm just a hobbiest? I usually only get to go to the shop once or twice a week.

[wilburpan]

I'd just use the plate on all of your stones. That's what it's there for.

If you're worried about cross contamination, flatten your 8000 grit stone first, then your 4000 and then your 700. If you get 8000 grit on your 4000 grit waterstone, that won't matter.

[Mark Reuten]

Hi Bob,

I think you're on the right track. I give my stones a rub together after every couple of uses and they have remained dead flat for years. I use a diamond stone also but unlike most others, I actually use mine to sharpen. I never saw the sense in just using it to flatten water stones.

I hollow grind, then use a DMT combination stone in a 300 and 1200 grit, then move to my 4000 and 800 water stones. Follow up with a strop.