Flattening waterstones... again

[Monte Milanuk]

Hello all,

I've been going back through various threads on flattening waterstones. What I have is a Norton 220 grit coarse stone, a Norton combo 1000/4000 grit stone, and one of Norton's flattening stones. After reading about how the latter is apparently the devil's own ;) as far as that sort of thing goes, it sort of explained why I had some odd low spots forming in the same places on my various stones.

I thought the Duo-sharp diamond plate would be the next answer, but then read about them getting 'eaten up' and wearing out - thankfully before I plunked down $90 for one plus shipping (no woodworking stores within several hours of where I live).

Then I see folks talking about just putting sand paper on a granite surface plate and flattening stones that way. Great! I have a couple granite surface plates just kicking around, courtesy of another hobby of mine :rolleyes: so I took the 'little' one that I got from Lee Valley or Grizzly a couple years back, set it in the bottom of the deep sink in the shop, put a sheet of Norton 3X 220gr sand paper on it and proceeded to flatten away. In fairly short order I got some good 'suction' on the stone, which I took to mean that it was flat relative to the surface plate.

When I went to use the stone, though, it appeared to have two high 'ridges', right down the edges, with a *big* hollow in the middle - those ridges were pretty clearly the only places making contact with the back of the chisel that I was trying to flatten. Tried flattening the stone again a couple times, but the only thing that seemed to change was that the '3x' sheet got pretty bald pretty quick like. Went back to 'flattening' with the Norton flattening stone as despite its various ills it seemed to do a better job than sandpaper/surface plater were managing.

Any ideas what I'm doing wrong here? I realize that at times I can be the sort who manages to break anvils with a rubber hammer, but I thought I had this one all lined out...

[David Gendron]

When you go to flatening your stones, scibe some lines with a pencil lenght and with wise so when you flaten the stone you have some ideas of when it's "thruly" flat... when all the lines are gone the stone should be flat!
Try that and see if it work!
I use a flatening stone and it work great so far!

[Mike Henderson]

I use the DMT diamond stones to flatten my waterstones and they work fine. I've used them for several years and the DMT's still work fine - they flatten waterstones quickly and easily. I'm sure they'll wear out some day but probably not for several more years.

Previously, I used sandpaper on glass but the DMT's are much easier to use.

Mike

[P.S. The Norton flattening stone is useless. It's worse than useless. It's a menace. It will make your waterstones dished.]

[David Gendron]

Mike, I'm sorry to contradict you but I uses it all the time and after you dresse it up, it work perfecly fine and way faster than the DMT... To each one there prefferences!

[Mike Henderson]

Mike, I'm sorry to contradict you but I uses it all the time and after you dresse it up, it work perfecly fine and way faster than the DMT... To each one there prefferences!
The problem with the Norton flattening stone is that you have to keep it flat. So you have to have some technique, like a DMT diamond stone or sandpaper on glass or granite, to flatten it. And you have to do it often because the flattening stone gets out of flat fairly quickly.

When you use your working waterstone, it always wears in the center. When you use the flattening stone on your working stone, you tend to wear the outsides of the flattening stone faster than the middle. So the flattening stone becomes convex.

Very quickly, what you're doing is using a convex stone to "flatten" a working stone which just makes the working stone concave.

Rather than go through the extra step of flattening the flattening stone, just use your preferred method of flattening to flatten your working stones. For me, that's a DMT diamond plate, but sandpaper on glass or granite works fine also.

And, yes, I had a Norton flattening stone at one time.

Mike

[dan sherman]

Great! I have a couple granite surface plates just kicking around, courtesy of another hobby of mine :rolleyes: so I took the 'little' one that I got from Lee Valley or Grizzly a couple years back, set it in the bottom of the deep sink in the shop, put a sheet of Norton 3X 220gr sand paper on it and proceeded to flatten away.

I don't own any water stones yet (waiting for the ones I want to be back in stock), but I think The grit of sand paper you used is the problem. I seem to remember people recommending 60-120 grit. After you got the stone flat then you could go to a higher grit to smooth the surface of the stone.

[dan sherman]

I seem to remember people recommending 60-120 grit. After you got the stone flat then you could go to a higher grit to smooth the surface of the stone.

Mike recommended 100-150 grit here (http://www.sawmillcreek.org/showpost.php?p=499549&postcount=17)

[Chris Friesen]

I don't own any water stones yet (waiting for the ones I want to be back in stock), but I think The grit of sand paper you used is the problem. I seem to remember people recommending 60-120 grit. After you got the stone flat then you could go to a higher grit to smooth the surface of the stone.

I use 400 grit on my 4000x stone, and 600 grit on my 8000x stone for flattening. I soak the stone and flood the sandpaper with water periodically. Goes pretty quickly.

I do try and make a point of using all of the stone, so I'll do a few extra strokes at each end and flip the stone around so I use both ends as well as the middle. Maybe it helps, and I figure it can't hurt.

[Bruce Mack]

I claim no expertise but, as recommended by others, I have used a 99 cent cinder block from Lowes as my surface for stones ranging from 220 to 5000 grit. I keep it on the floor and spritz it with water from a plastic bottle. There's plenty of surface area and the stones test flat by straightedge. I spread some 90 grit silicon carbide once, but suspect it's not necessary. Even the Shapton 5000 washes off smooth and continues to give a mirror finish to the blade.

[Wilbur Pan]

In fairly short order I got some good 'suction' on the stone, which I took to mean that it was flat relative to the surface plate.


When you go to flatening your stones, scibe some lines with a pencil lenght and with wise so when you flaten the stone you have some ideas of when it's "truly" flat... when all the lines are gone the stone should be flat!
Try that and see if it work!
I use a flatening stone and it work great so far!

The tip with the pencil lines is key. Suction may not mean much in terms of flatness. Checking your flattened waterstone with a straightedge will also help a lot.

One other thing that I do is to vary the angle of the waterstone as I flatten my waterstone. In fact, instead of running the waterstone along the length of my flattening plate, I make an "X" pattern, running it along one diagonal from corner to corner, then the other, then I go along the length of the flattening plate. This should avoid the "ridge down the sides" problem you're having.

Here's a link (http://www.shapton.co.jp/Products/kubo/use_a.html) to illustrate what I mean. It's in Japanese, but you should be able to figure it out.

You also don't have to push down hard on the stone as you flatten it.

[Sam Takeuchi]

I'll give a translation for the page Wilbur posted even though it's pretty self explanatory.

Method of sharpening stone correction

* Place the flattening plate on a stable place.
* Pour water on the flattening plate until water fills the grooves.
* Place the sharpening stone (after soaked in water) on flattening plate and repeat as in diagram 1 and 2 for a few times, and turn the stone 180 degrees, proceed in the same fashion until the stone is flat. Lightly finish as in diagram 3.
* Remove sharp corners and edges.

-1 Flush any coarse grit slurry before flattening higher grit stones. Pay special attention prior to flattening finishing and polishing stones.

-2 Using coarse grit stone on the flattening plate will accelerate wear on diamond. For coarse grit stones, correct the surface by using other coarse stones to remove ridges and dish out.

[Tom Adger]

Similar to what Bruce said, I use a cinder block, but I use it to flatten the Norton flattening stone. I then use the flattening stone to flatten my waterstones.

[Michael Schwartz]

I have used flattening Plates, flattening stones, sand paper, diamond stones, and they all work. Diamond stones are a bit slow in my opinion.

I have heard about the cinderblock method from others too, might have to try it sometime.

[Monte Milanuk]

Any ideas as to why the concavity was forming with the sandpaper & surface plate? Like I mentioned earlier, it wasn't just a little bit... basically a big 'hole' with a 'rim' right at the edges of the stones.

[Sam Takeuchi]

Is your granite plate flat? Is it big enough that the whole stone is on the plate?

[Jerome Hanby]

Any ideas as to why the concavity was forming with the sandpaper & surface plate? Like I mentioned earlier, it wasn't just a little bit... basically a big 'hole' with a 'rim' right at the edges of the stones.

This sounds similar to the process used to grind a telescope mirror. The blank and tool both start out as flat disks of glass. As you add abrasives and grind them together the blank gets concave and the tool gets convex. Any convex activity happening on your plate?

[Frank Drew]

I've never used Norton waterstones, but for Japanese stones the cement block (plus water and fine sand) works great to flatten the coarser stones, then flatten the fine stone on the well-rinsed and now flat coarse stone. Done and done.

[george wilson]

I don't use water stones,but learned the trick of using the side of an old fashioned sandstone grinding wheel to flatten stones. It even works quickly with black Arkansas stones.

I went into the gunsmith's shop one day in Col. Wmsbg.. One of the guys was sanding away at a black Arkansas stone with 600 grit wet or dry paper wrapped around a file!

They had a sandstone wet grinder in the shop,so I took it out f its trough and laid it flat. I think it took 10 minutes to flatten the extra hard Arkansas stone.

Failing to have the sandstone wheel,I recommend you use a diamond stone to flatten water stones. I've even flattened new white Spyderco ceramic stones with mine. Worked fine. Use lots of water,but do not let the silt go down your drain and eventually plug up your pipes.

[Mike Henderson]

This sounds similar to the process used to grind a telescope mirror. The blank and tool both start out as flat disks of glass. As you add abrasives and grind them together the blank gets concave and the tool gets convex. Any convex activity happening on your plate?
Hey! Another guy who has hand ground a telescope mirror. Interesting experience isn't it?

Mike

[Mike Henderson]

I've never used Norton waterstones, but for Japanese stones the cement block (plus water and fine sand) works great to flatten the coarser stones, then flatten the fine stone on the well-rinsed and now flat coarse stone. Done and done.
Good idea. I'm going to remember that suggestion. Thanks!

Mike

[steve swantee]

Here's another vote for the cinder block method-I have been using it for several years with no problems. Cheap and effective.

Steve

[Monte Milanuk]

Is your granite plate flat? Is it big enough that the whole stone is on the plate?

Sam,

It should be; 9" wide by 12" long granite surface plate from either Lee Valley or Grizzly (can't recall which). Prior to this the only thing it had been used for was as a massive base for some sensitive measuring equipment. It is as close to perfectly flat as I can tell using a Lee Valley steel 24" straight edge that hangs on the wall and is used solely for reference purposes. No visible light under the straight edge.

Thanks,

Monte

[David Gendron]

Doing a figure 8 with the stone help also to ceek things flat and to wear the substrat evenly.

[Narayan Nayar]

What do you guys use to flatten your cinderblock? :)

[Mike Henderson]

What do you guys use to flatten your cinderblock? :)
I've never used a cinder block but I always assumed you just kept moving to a different location on the block and got a new block when you used all the surfaces on one. For anyone who's associated with construction, cinder blocks are readily available.

Mike

[Don Dorn]

I really take the easy road. I have a 180 grit diamond sharpener that I picked up at Harbor Freight. After using it to flatten the water stones (using the pencil grid technique) - it comes out perfectly flat. Well, at least according to the straight edge I used many times to check it. I don't even bother now.

[Bob Barkto]

Monte,

If you are going to use the Norton 3X, use it dry. It's not a waterproof paper.
If you want to use a wet process get some waterproof paper from an auto supply place. Get the coarsest grit they have. Change it frequently.

Glue the paper to the plate (no matter which paper you use) or you'll round over the edges of your stone.
3M lo tac spray work well, spray the back of hte paper.

Hope this is helpful.

[John Coloccia]

I use 80 grit sandpaper stuck to a granite plate with turners tape on the corners (i.e. I stay away from the corners when flattening). I spritz the stone with water lightly, wipe off the excess, and rub it on the sandpaper for a few seconds. I happen to use 80 grit to flatten everything from my 1000 to 8000 grit stones. The 1000 grit still shapes metal, the 8000 grit still gives me a mirror finish, and the in betweens are suitably in between, so I don't bother worrying about somehow matching the sandpaper grit to the stone's grit. 80 grit for everyone.

That stupid flattening stone Norton sells is just junk, IMHO. I haven't read the whole thread, so I don't know if someone else likes it, and sorry if you do as no offense is intended, but it just pushes the problem down to "how do you flatten your flattening stone?", plus the thing is way too small to work properly unless you sit there and simply wiggle the stone back and forth by 1/8". Awful device.

I do a lot of hand tool work,and thus do a LOT of sharpening. My workshop time is really limited as it is, so I just really don't have time to futz around making this a big production. My next step will be a Tormek, and then I won't have to worry about any of this nonsense anymore :D I've told myself that I will justify the purchase the day I walk into the shop to work and end up doing nothing but sharpening tools by the time I have to call it quits for the night.

[Tim Sgrazzutti]

Make sure you rinse the debris off the stone and paper every 3 or 4 strokes. If it builds up it could cause concavity.

BTW, I have a nice Starrett surface plate, and prefer to do most flattening on that with silicon carbide paper. The 220 norton wears too fast for me to get anything flat with. If I have something flattened off the plate, it's easy to clean up the surface finish with the finer stones without wearing them too much.

For stone flattening, I use a hunk of marble tile with SiC paper. It was easy to make the tile pretty darn flat by lapping on the surface place with SiC paper. It transports to the sink or bucket much easier than a surface plate, and saves the surface plate for the finer things it was intended for.

[David Keller NC]

Sam,

It should be; 9" wide by 12" long granite surface plate from either Lee Valley or Grizzly (can't recall which). Prior to this the only thing it had been used for was as a massive base for some sensitive measuring equipment. It is as close to perfectly flat as I can tell using a Lee Valley steel 24" straight edge that hangs on the wall and is used solely for reference purposes. No visible light under the straight edge.

Thanks,

Monte

Monte- What you're likely experiencing is common with using the sandpaper method for flattening waterstones (I use this method as well, btw). What tends to happen is that the piece of sandpaper doesn't get equally "broken in", particularly if you're rubbing the stone back and forth in one place, or with the same pattern. This can also happen if you're putting any appreciable pressure on the stone itself - you want to just use enough force to keep the stone flat on the paper and keep it moving with no additional pressure. During the flatening process, flip the stone around end-for-end frequently, and use the whole piece of sandpaper including going slightly off of the edge.

One other note - you really cannot use a dry piece of sandpaper for this purpose. The combination of the water and wet/dry sandpaper is important, because it allows the slurry that's created to distribute itself all over the surface. If you attempt this with dry paper, you will quickly build up a relatively immobile layer of waterstone dust in the center of the paper, and your surface that you're flattening against will no longer be flat. That in and of itself will wear a hollow in the center of the waterstone.

[John Coloccia]

One other note - you really cannot use a dry piece of sandpaper for this purpose. The combination of the water and wet/dry sandpaper is important, because it allows the slurry that's created to distribute itself all over the surface. If you attempt this with dry paper, you will quickly build up a relatively immobile layer of waterstone dust in the center of the paper, and your surface that you're flattening against will no longer be flat. That in and of itself will wear a hollow in the center of the waterstone.

I think you nailed it right there. This is a great way to dish your stone, and it'll drive you nuts trying to figure out how you can possibly have a depression in the middle of the stone! :D

[Pam Niedermayer]

I'll give a translation for the page Wilbur posted even though it's pretty self explanatory....

Well, of course it wasn't all self explanatory and your translation added critical instruction that can't be deduced from graphics alone. It's wonderful that you can translate so well.

Pam

[Danny Burns]

I do a lot of hand tool work,and thus do a LOT of sharpening. My workshop time is really limited as it is, so I just really don't have time to futz around making this a big production. My next step will be a Tormek, and then I won't have to worry about any of this nonsense anymore :D I've told myself that I will justify the purchase the day I walk into the shop to work and end up doing nothing but sharpening tools by the time I have to call it quits for the night.

I found that the Tormek wheel was just as much fuss as any other sharpening system out there. You have to have a trued wheel, and some jigs react to hand pressure causing results to vary.
I do like my Tormek for gouges though, sine it does a real nice job on the rounded bevels.

[michael osadchuk]

Monte- What you're likely experiencing is common with using the sandpaper method for flattening waterstones (I use this method as well, btw). What tends to happen is that the piece of sandpaper doesn't get equally "broken in", particularly if you're rubbing the stone back and forth in one place, or with the same pattern. This can also happen if you're putting any appreciable pressure on the stone itself - you want to just use enough force to keep the stone flat on the paper and keep it moving with no additional pressure. During the flatening process, flip the stone around end-for-end frequently, and use the whole piece of sandpaper including going slightly off of the edge.

One other note - you really cannot use a dry piece of sandpaper for this purpose. The combination of the water and wet/dry sandpaper is important, because it allows the slurry that's created to distribute itself all over the surface. If you attempt this with dry paper, you will quickly build up a relatively immobile layer of waterstone dust in the center of the paper, and your surface that you're flattening against will no longer be flat. That in and of itself will wear a hollow in the center of the waterstone.

David,

I flatten my Japanese synthetic and natural waterstones when they are dry on dry sandpaper taped around the perimeter with Lee Valley transfer tape on granite or marble floor tiles or kitchen backsplash material - and I get flat stones as checked by machinist squares/straight edges. (I didn't like the greater mess and greater cost of using wet n dry sandpaper, plus I have duplicate stones in just about all grits so I dry out time isn't a factor for me.)
Yes, the dry stone dust comes of the stone easily and just sits there - but because it is dry it doesn't attach itself to the paper with any degree of adhesion and can easily and quickly be blown off or released from the paper with the pass or two of a woodworking crepe 'eraser'.

good luck

michael