Flattening Waterstones

[Denis Tranchemontagne]

I have a couple waterstones and have never flattened them.
Typically I use a combination scary sharp on a piece of granite tile andwaterstones to sharpen planes and chisels.

I was wonder what people use to flatten their stones.

Thanks

Denis

[Danny Thompson]

I use this Norton Flattening Stone.

http://www.woodcraft.com/family.aspx?FamilyID=5775

[Mike Henderson]

I use this Norton Flattening Stone.

http://www.woodcraft.com/family.aspx?FamilyID=5775

My experience with that Norton flattening stone has not been good. The problem is that the flattening stone must be kept flat or it transfers its non-flat shape to the working stones.

I use a DMT extra coarse diamond stone for flattening my working stones.

Mike

[Cliff Rohrabacher]

My experience with that Norton flattening stone has not been good. The problem is that the flattening stone must be kept flat or it transfers its non-flat shape to the working stones.

I had a job run some many many years ago that required that I hand lap my parts to a flatness spec that was just a couple light bands (nanometers).

I used lapping compound and an old cast iron lapping table that was most assuredly not flat.

The trick is never to have any repeat motion. Random is the key: random pressure, random rotation, random stroking. It's a skill that is only good for hand lapping and applies just about nowhere else.

[Eddie Darby]

If you have a piece of granite already then you can use the surface plate to flatten your stones.

You should be flattening them quite frequently.

The fast cutting waterstones act fast because they wear so easily, producing fresh cutting compound in the process. The downside to this desirable fast performance is that they dish fast as well.

I have a DMT diamond stone, x-coarse/coarse, that I use, even though I have a granite surface plate which is much flatter, for convenience sake, because I can take the diamond stone to the waterstone, and do a quick touch-up very easily in between tools.

[Sam Yerardi]

Another option that I've heard of and read about in FWW (I've never tried it myself) is to use one stone to flatten the other. Place them together with a small amount of water, and rub across each other. Don't remove the paste that develops. Eventually they will flatten each other. If I can find the article I read I'll post the issue #.

[Mike Henderson]

Another option that I've heard of and read about in FWW (I've never tried it myself) is to use one stone to flatten the other. Place them together with a small amount of water, and rub across each other. Don't remove the paste that develops. Eventually they will flatten each other. If I can find the article I read I'll post the issue #.

This point has been discussed quite a bit before. If you rub two surfaces together, you get two conforming surfaces - not necessarily two flat surfaces (two flat surfaces are one possibily since they are conforming). The most likely outcome, however, is that one surface becomes convex while the other becomes concave.

Mike

[Christoph Schmitz]

Hi,

there is one (low-cost, I might add) technique that has been popularized in the German handtool community by Friedrich Kollenrott. He proposes to flatten your waterstones on bricks. In order to keep the bricks flat, you employ a technique that is well known in other areas (he quotes the making of precision surfaces in optics).

The key idea is to maintain three bricks and get these flat by rubbing them on one another in a cyclic fashion. If you number the bricks 1-2-3, the order would be: 2 on 1, 3 on 1, 1 on 2, 3 on 2, 1 on 3, 2 on 3. With this technique, you cancel out the effect of one brick becoming concave and the other one convex.

You can add grooves to the bricks to take away the swarf, and use silicon carbide powder to speed up the flattening of the bricks.

Those who speak German or want to take a look at his pictures, see http://www.woodworking.de/schaerfprojekt/schaerf2.html.

Best regards,
Christoph

[Sam Yerardi]

Mike,

It's good to know that. Like I said I've never tried it. Thanks!

[Bill White]

Another option that I've heard of and read about in FWW (I've never tried it myself) is to use one stone to flatten the other. Place them together with a small amount of water, and rub across each other. Don't remove the paste that develops. Eventually they will flatten each other. If I can find the article I read I'll post the issue #.

I agree w/ Sam. Been doin' this for years w/ good results.
Bill

[Sam Yerardi]

What makes me think this is worth trying is it does make sense. I don't remember the author's name in FWW but he even went so far as to suggest having an extra stone for each one just for this purpose.

[Larry Heflin]

Rob Cosman demonstrates and uses this technique in one of his videos.

Another option that I've heard of and read about in FWW (I've never tried it myself) is to use one stone to flatten the other. Place them together with a small amount of water, and rub across each other. Don't remove the paste that develops. Eventually they will flatten each other. If I can find the article I read I'll post the issue #.

[Mike Henderson]

Rob Cosman demonstrates and uses this technique in one of his videos.

I believe Rob Cosman uses THREE stones. If you do some research on the web or even do some research on your own with two surfaces you'll see that two surfaces will not (in general) produce a flat surface.

In fact, when hobbyist grind their small telescope mirrors they use a mirror blank and a glass tool. Both are flat to start but the blank quickly becomes concave. They just rub them together with a grinding compound between them.

Mike

[added note] There is a known technique for producing a flat surface by rubbing three surfaces together but not for using just two surfaces.

[Matt Z Wilson]

So I don't really subscribe to the whole waterstone idea, I prefer oilstones, but I've been using a system for flattening chisel backs and plane soles for quite a while that works pretty well. I went to a scrap yard and found a piece of 5 x 8 cast iron that was about 1 inch thick (who knows what it was in a previous life) Cost: $16. Then I took it to a machine shop and had it surface machined on one side to flatness to .0005. Cost $5. Or if you're really ambitious you can have them machine grooves in it like a real lapping plate but that's more expensive. Now you can use the abrasive of choice for the lapping grit. Being cast iron and unhardened, the grit sticks into the surface of the plate and wears on whatever you are flattening. Diamond grit works very well, but other compounds work equally as well for less money. Now jut mix up a slurry of honing oil (or water) and the grit and you're in business. The plate hasn't been dressed in at least 5 years and yet is still flat to within .005. And it can be reflattened at the machine shop and being very thick will last long past my use for it. I suppose it would work just as well for waterstones, just make your lapping slurry out of water instead of oil and be sure to clean the plate thoroughly when you're done.

[Dan Racette]

Matt Wilson.

Looks like your first post on the Creek Matt. Welcome!

Dan