# Waterstone flattening



## jsheaney (Jun 25, 2007)

I have Norton waterstones and the Norton flattening stone. I'm getting pretty good at sharpening my plane blades and chisels, but I'm very unhappy with the flattening stone. It doesn't itself stay flat, which keeps messing with the geometry of my plane blades.

There weren't really any instructions that came with the flattening stone. I started out just putting it in one hand and a waterstone in the other and just rubbed them together, as if I was rubbing my hands together. Unfortunately, this made the flattening stone concave, which made made by waterstones convex, which made my blades concave. Concave blades are bad. The corners dig into the workpiece.

At that point, I flattened the flattening stone with sandpaper taped to my tablesaw. That cleaned everything up.

I then watched the DVD that came with the system and carefully noted how the demonstrator used the flattening stone. He just set it on the table and gently moved the waterstones around on top of it. I've been doing that ever since.

Now, I've noticed that my flattening stone is convex, which means my waterstones are concave, which means my blades are convex. This is not as bad of a problem as before, but it's still annoying.

When I talk about the stones being concave or convex, I mainly am referring to the length of the stones. I think what's happening is that the lapping of the back of the blades (deburring) is where the geometry is being most affected. The relative size of the blades and the waterstones means that I turn the blades sideways and lap up and down the length of the waterstones. The width of the blades, therefore, is picking up the geometry of the length of the waterstones.

I suppose the answer here is to flatten my flattening stone again, but clearly I have to do that regularly. I don't like that prospect. Plus, it's already significantly worn down. And I want to spend less time sharpening, not more.

I'm looking for advice on keeping my waterstones flat. Maybe a diamond stone?


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## GaryK (Jun 25, 2007)

I would suggest a diamond stone. It will always be flat.


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## mattsanf (Jul 20, 2007)

I agree. In fact, I use a diamond stone to flatten my Norton waterstones….I just rub my coarsest DMT diamond stone back and forth on the surface of the Norton waterstone while running them both under the faucet. Doesn't take long to make it perfectly flat again.


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## MikeLingenfelter (Feb 19, 2007)

I don't really like that flattening stone, for that reason. You still have to dress the flattening stone on a regular basis, and personally I think it's way to course. It removes way more material than is needed. I use a piece of float-glass (a slab of granite works nice too) and 220 wet/dry sandpaper. I've done a lot of research on this topic and there are more ways to sharpen tools than I can even count. There are two DVDs out there that I think are the best. They take different approaches and I have gotten good results with both. I have settle on the David Charlesworth approach. The other is from Rob Cosman, and he uses another 1000 grit stone to flatten his stones. Both DVD address the topic of keeping your stones flat.

David Charlesworth
Hand Tool Techniques Part 1: Plane Sharpening

Rob Cosman
Hand Planing and Sharpening


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## greybeard2025 (Jul 3, 2007)

I agree with Matt. Just finish making and sharpening a skew chisel from a cheap straight chisel bought from a big box store. Used 4000-6000 Norton waterstone to hone the skew bevel after grinding on a slow speed grinder. Used a coarse DMT diamond stone to flatten the waterstone before and after use. One big caution. Dont use the garbage disposal side of the kitchen sink. Fine grit is tough on the disposal bearings. Dont ask how I know.

-Greybeard


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## woodspar (Mar 6, 2007)

Yes, I use the DMT diamond stone to flatten my 1000/4000 grit stone. It is also good to true up the plane body and sole.


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## Dorje (Jun 17, 2007)

I have the Norton flattening stone new in the box - looks like it'll stay there after reading this! I've been pretty happy keeping my waterstones flat with my 12×15" 3/8" thick plate glass and whatever-grit-is-necessary-for-the-purpose sandpaper combination (it's a bit cumbersome to use in the sink though - even in a utility sink). Also, have a granite slab which it great for dead flat work - like lapping backs, etc…

I think the diamond stone would be an improvement to the glass and sandpaper method to flatten stones though.

Isn't it surprising how often you need to true up the face of waterstones! I've done a lot of reading over the past few years, but this was one point that I had to learn on my own.


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## jsheaney (Jun 25, 2007)

Thanks for the input, everyone. Woodcraft is having a sale this weekend. I guess I'll end up getting a DMT diamond stone. I don't mind having to flatten the waterstone. I think of it as cleaning them up. I'd want to do that anyway. I do mind having to flatten the flattening stone. At some point, the madness has to end.


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## WayneC (Mar 8, 2007)

According to the DMT salesman at last springs woodworking show the flattening stone is good for 6000/8000 grit stones where the stones will stick to the diamond stones. Anyone have any experience with this?

I had picked up a flattening stone just prior to buying a WorkSharp sharpener. Since buying the machine, I have not used my water stones. If I get some time, I will play around with them some.


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## Kaleo (Jan 25, 2007)

I just use a sheet of 100 grit paper taped to a piece of 1/2 inch glass. I strike some pencil lines across the stone and sand until all the pencil lines are gone. Then the stone is flat and I sharpen, depending on how much sharpening I have to do I repeat the process a few times.


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## jsheaney (Jun 25, 2007)

Wayne, I'm having a hard time parsing what you said. What's this about sticking to the diamond stones?


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## mattsanf (Jul 20, 2007)

As long as you are running the stones under a faucet while you are flattening them with the DMT, I've had no problem with the grit sticking…


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## WayneC (Mar 8, 2007)

Surface tension can make the high grit stones stick to the diamond stone. I belive this is the thinking driving the groves in the top of the flattening stone.


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## jsheaney (Jun 25, 2007)

Well, I went to Woodcraft and picked up a DMT plus fine/extra fine stone. I went in there thinking I would get a coarse grit, but they were out of those and I wasn't walking away empty handed. I'm actually perfectly OK with these grits, though, now that I have used them. I use the fine side to flatten my waterstones and it works great. I think I can say that my waterstones have never been this flat. By that, I mean that they are just flat; they are also smooth.

There is the issue of surface tension making the stones stick together. However, the motion is actually parallel to the surfaces and so the surface tension doesn't really interfere with the shearing action of the flattening process. Also, the surface tension increases as the stones get flatter, so it actually provides feedback on how you're doing. I don't see it as a problem, at all.

I actually used both the fine and the extra fine grits to lap two of my plane blades that had gotten out of whack. I think they did a good job. Also, they are physically larger than my waterstones, which helped. Another nice thing is that I didn't have to soak it, which I would have had to do with my coarse waterstone. I have one more blade to fix and I think I will lap that on the waterstone, just by way of comparison. The extra coarseness might make it go faster.

The other nice thing about the DMT stone is that I can use it for my card scrapers, which will be better than using my waterstones.

I'm pleased. Now, I just hope they stay as flat and as sharp for as long as they claim.


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## mot (May 8, 2007)

This was a good discussion.


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## Dorje (Jun 17, 2007)

Agreed!


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## AttainableApex (Aug 24, 2010)

yup, good discussion.
i to purchased the flattening stone from notron (came in a set). it is very annoying to say the least.
ya i think i am going to purchase a diamond stone.
how much have you guys paid for your diamond stone and how big is it.
im guessing i need one a little bigger than my water stones. i see an extra large version (11.5"x2.5") at highland woodworking for 70.


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## Loren (May 30, 2008)

I usually use a sheet of glass or a flat cast-iron surface. The abrasive
is a sanding screen used on a circular floor sander. Even after the
screens are no good for wood, they work fine on waterstones. The
screen is an open-weave so it doesn't load up. Flattening goes quickly.

As an aside, you can learn to work your stones more evenly by
using a figure-8 motion when you hone. I worked on this habit for
awhile and don't have to flatten the stones very often.


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## jsheaney (Jun 25, 2007)

Wow. Old thread revisited. What's that, over three years? So, since that time, I actually haven't changed a whole lot, but some. Here's an update.

I still use the fine/extra fine DMT stone to flatten my waterstones (4000/8000). In fact, that's all I use it for.

The 4000 (white) side of my combination Norton stone wore down. There's still plenty of life on the 8000 (yellow) side, so I bought a new 4000 Norton stone and just use the 8000 side of the old stone. I think the pair of stones will last years. Obviously, as a starter the combo stone was a good value, but I would now recommend just buying the single grit stones.

I found the fine/extra fine DMT stone to be too fine for doing the initial work of re-honing my blades, so I bought a coarse/fine DMT stone. That's better, but there is also a coarse, extra coarse and I think I would prefer that one. As it stands now, I spend most of my time on the coarse side of the DMT stone, a short amount of time on the 4000 waterstone and even less on the 8000 (aside from lapping the backs for deburring). Since I'm going right from the coarse DMT to the 4000 waterstone, I think I could go faster by starting on the extra coarse and then a short amount of time on the coarse side.

There's one other notable change. Most of my plane blade sharpening is for the blades that go with my Lee Valley set of bevel up planes. I used to use the Veritas Mk II honing guide, but I switched to the cheaper, simpler side clamping guide. The Lee Valley blades are so thick that the backs are raised above the guide, which makes it really easy to lap the back while in the guide. This makes it easier to use the whole stone; you aren't limited to by the amount the blade sticks out of the guide.


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## hokieman (Feb 14, 2008)

Sharpening is my biggest frustration in woodworking. I just recently bought a DMT DiaSharp coarse plate to flatten my water stones. This is a solid plate with the diamond imbedded in it - not the DuoSharp DMT stones where the diamond is imbedded in a "mesh". Anyway, when I received it, it wasn't all that coarse (320 grit) but I decided to first rework the iron on anold No. 7 plane which is pretty soft steel. I reworked the primary bevel directly on the DiaSharp stone. I was amazed at how fast it cut. I'm thinking, this stone will really do the trick to sharpen my fine water stones. Thought I had found the Holy Grail! Well, I honed the iron on my water stones, intermittently ensuring water stone flatness with the Diasharp plate. After about 5 "flattenings", I noticed the Diasharp wasn't cutting it. Ran my finger across the plate and it was smooth! It was completely shot! I was PO'd. It won't do anything at all any more.

So diamond plate flattening of water stones didn't work for me. One thing I am thinking is maybe the Diasharp (solid plate) is not the best diamond bench stone and the DuoSharp (mesh) is a better means. Maybe the waste grit from the water stone will go into the void space in the mesh and not wear the diamonds down???? Anyone got any suggestions on this? The LN guys use a Shapton lapping plate at their shows to flatten water stones but who has 320 bucks laying around to keep waterstones flat?

As of right now, I think I am going to get the coarse/extra coarse DuoSharp for re-doing all primary bevels and use water stones for honing the secondary bevel but keep the water stones flat with my old 220 grit wet 'n dry sandpaper on my granite block.

Any thoughts on this would be greatly appreciated.


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## AttainableApex (Aug 24, 2010)

they say to really wash out the diamond stone.
i just ordered the diasharp extra coarse 11.5in, i hope it does the trick.
i was going to go with the 10in by 4in one but it was 90 bucks and was only coarse i think or less.
i really need to use my chisels in the next few days and im left here with dull chisels right now, lame.


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## racerglen (Oct 15, 2010)

I use the Veritas stone pond system, keeps the stones that need it wet, the top's ultra flat glass and
they included the right grit of PSA backed wet dry sandpapers with it..
Or a chunk of equaly flat Granite left over from countertops..


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## jsheaney (Jun 25, 2007)

I've never had any problem using a DuoSharp to flatten a stone. I only wish I had a coarser stone to more aggressively remove steel at the start of my honing. One thing that does seem to annoy people is that the DMT stones start out cutting more aggressively when brand new. They then seem to get duller, but they are really settling into their steady state. They seem to last a long time after that. Note that I only have experience with the DuoSharp; not the DiaSharp.


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