Flattening my Shapton waterstones

[overland]

I'm using a couple Shapton Pro ceramic waterstones for sharpening. About two years ago I got an Atoma 400 diamond stone to flatten my water stones--Nortons at the time. I'm an occasional woodworker and have used the Atoma only a modest amount, mostly for flattening the water stones but also once in a while to flatten the back of an old chisel or plane blade. It's taking a long time to flatten the Shaptons these days--even when I do it after just one use. I wonder if the Atoma 400 is worn out already or if the ceramic stones just take a long time to flatten. The Atoma was expensive, but wonder if I should look for something else?

[Wilbur Pan]

I don’t remember how long ago I got my Atoma 400, but it’s been a lot more than two years ago. It flattens my Shapton Pros pretty quickly, about 30-60 seconds. Here’s an example: http://giantcypress.net/post/668546073/j...pened-with

It may be that the Shaptons take longer to flatten than Nortons. But it still shouldn’t be a huge chore to do so.

[AHill]

How often do you flatten your stones? When you use your waterstones, are you spreading out the wear across as much of the stone as possible? The Atoma and any other diamond plate will cut aggressively when new, then taper off. Don't expect them to cut as quickly after they break in. I also have a diamond flattening stone, and I only use it to flatten my waterstones. You will also benefit from flattening often vs. waiting until the end to flatten them. Especially on the lower grit stones, which wear a lot quicker than the high grit stones. I flatten mine after each tool. Shaptons are pretty hard stones. They take longer to flatten vs. Nortons, Naniwa, or even Sigma Power stones. It may also be possible you are not soaking your stones long enough. If the stone gets clogged with swarf, it'll be harder to flatten vs. one that's cleaner. Or, alternatively, if you are soaking your stones too long, the stone itself is getting softer and will wear quicker - hence the longer time to flatten it.

[Steve Friedman]

I agree that it's unlikely to be the Atoma. I assume you're using a 400 grit Atoma and trying to flatten Shaptons that are 1000 grit and higher. I find that an Atoma 140 is much better for flattening my 400 and 320 grit stones. In fact, I have read that the Sigma 400 grit stone can reduce the effectiveness of the Atoma 400.

I assume it's possible that you could have worn out the Atoma with flattening backs, but if you only did that occasionally, I can't imagine that it would be an issue. Like Alan, I don't use my Atoma for anything but stone flattening.

The thing that strikes me, however, is your comment that "it's taking a long time to flatten the Shaptons . . even when I do it after just one use." Not sure what you consider one use, but the Shaptons are pretty hard and shouldn't dish that much after sharpening a single blade. So here are some suggestions:

1. I've never heard of this being a problem, but double check to make sure the Atoma is flat. After all, it's just a block of aluminum. If it's out of flat, I would go back to whoever you bought it from.

2. Assuming the Atoma is flat, are you are sure that you're getting the stone flat before you start using it - with the pencil hash marks? I find that's the best way of telling if the stone is flat. In your case, I would do it twice. Flatten till the hash marks are gone. Then put new hash marks on and reflatten for 10 or 20 seconds. Then check to see if the pencil marks are abrading uniformly over the stone. If the stone was flat after you removed the hash marks the first time, the 2nd set of pencil marks should abrade evenly and quickly.

3. Is the Atoma clean? I find that mine often gets gunked up with grit and needs to be rubbed cleaned (just with water and my fingers). This is especially true of the higher grit stones.

4. Are you using a ton of water while flattening? I know you can do it like Wilbur does (relatively dry), but I find it helps to do it under running water to wash away the grit that you're removing and prevent the Atoma from getting clogged.

5. Are you soaking the Shaptons at all? If yes, you need to flatten after the soak. I believe Stu Tierney once said that a stone that's flat when it'a dry could be out-of-flat after soaking.

6. Although it sounds unlikely, you might want to use a 10X or 15X jeweler's loupe to check out the surface of the Atoma. Because of the diamond pattern, it might be possible to see if the diamond clusters look damaged or worn.


Good luck and please report back when you figure it out.

Steve

[overland]

I'm using an Atoma 400 on 1000 and 8000 Shapton Pros. I haven't done so religiously--I'm lazy--but I generally flatten after each use, such as sharpening a plane blade. I do this when the stones are dry, not wet, though I wash off the Atoma if it gets clogged. But it takes a lot of work to reach that point, especially with the 8000. I try to use the whole stone, although with some tasks, such as polishing the back of a chisel, it's hard not to use the edges. I'm beginning to think that maybe I shouldn't have used steel on the Atoma. On the other hand, maybe I'm just seeing the natural dulling that happens after initial usage-that "breaking in" period.

[Mike Brady]

You are using a sharpening medium to flatten another sharpening medium. Something has got to give and the give is going to be from both. I believe that only the Dia-Flat from DMT has a specific coating to protect itself from that which it is flattening. I don't know how long that coating is expected to last, but I'm pretty sure it won't be forever. The key is to protect the matrix in which the diamonds are embedded. When diamond plates fail it is because the diamonds are going down the drain after having been loosened from the matrix. Softer steels also can pull diamonds off the plate. You mentioned that your Atoma plate has been used to flatten irons as well as flatten stones. Its sounds like you have the same complaint so often heard about diamond stones: they don't last.

[Steve Friedman]

overland said:

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I'm using an Atoma 400 on 1000 and 8000 Shapton Pros. I haven't done so religiously--I'm lazy--but I generally flatten after each use, such as sharpening a plane blade. I do this when the stones are dry, not wet, though I wash off the Atoma if it gets clogged. But it takes a lot of work to reach that point, especially with the 8000. I try to use the whole stone, although with some tasks, such as polishing the back of a chisel, it's hard not to use the edges. I'm beginning to think that maybe I shouldn't have used steel on the Atoma. On the other hand, maybe I'm just seeing the natural dulling that happens after initial usage-that "breaking in" period.

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Based on that description, I'm even more puzzled because those stones shouldn't need much (if any) flattening after sharpening one plane blade. I assume all you're doing with the 8000 is honing a small secondary bevel. So, even if the Atoma is worn, I would think that it should still be able to do some amount of flattening.

And, if the Atoma is getting clogged, I would think that means it's abrading some of the stone, right? Maybe not as fast as you would like, but it seems like it's doing something.

As with anything sharpening related, it's always about eliminating variables. Whenever I notice that a stone is behaving weirdly, invariably it's because I haven't gotten it really flat. So, I would go back and flatten the stones twice - using pencil marks each time. Double check the stones with a straightedge. When you're certain they're flat, sharpen a blade. When you're done, see how long it takes to re-flatten the stones.

One other thought is to check you're flattening technique. I love the one Wilbur demonstrates because I think it reduces the risk of applying uneven pressure on different parts of the stone while flattening. But, if I'm flattening under running water, I need to make sure to flip the stones (end-to-end) and switch hands to make sure I'm giving all areas of the stone an equal amount of attention.

If all else fails, you can take Mike's suggestion and buy the DiaFlat, but it's not cheap. Since adding an Atoma 140, it's the one I use for any of stone at or below 1000 grit. I think the 400 works better for the higher grit stones. No idea if the stones care, but the 140 grit Atoma seems to remove too much material, so it clogs up and sticks.

Steve

[Steve Friedman]

On another note, I'm really surprised no one has chimed in yet to suggest oil stones.

Or a Tormek.

Sorry, I couldn't resist. Haven't had a good sharpening thread in a while.

Steve

[Mike Brady]

Chris Schwarz handles that situation by not allowing any sharpening threads on his LAP forum. He can do that because he's an anarchist.

[Rob Young]

Steve Friedman said:

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On another note, I'm really surprised no one has chimed in yet to suggest oil stones.

Or a Tormek.

Sorry, I couldn't resist. Haven't had a good sharpening thread in a while.

Steve

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Wait, you want to flatten your waterstones with an oilstone? Seems an odd choice but hey, whatever floats your boat. Or separates your oil and water.