flattening stones

[Noah Wagener]

What are some of the methods people use for flattening bench stones? Particularly the man made Japanese water stones. I have used an extra course diamond stone. I recently bought a rough water stone because the above diamond stone was taking forever to flatten the back of a plane blade and i figured the water stone never really loses cutting ability. Now that i had 2 water stones i tried rubbing them together and it seemed to take out the dish and a lot faster than the diamond stone (do these wear out? after less than 2 years?) But i cant really tell if the stones are flat, just that they have full contact between each other. One could be convex and one concave.

A local kitchen countertop place sells granite sink cutouts. Is it possible to flatten granite w/o power tools? I was thinking the bench stone could flatten itself from its slurry on top of the granite? RUb the coarse stone on it first to get a more aggressive slurry. I can't do this on the diamond stone because I have determined after several days of trying to flatten a block plane on it that not only has its cutting ability severely waned very quickly; it is not flat either.

thanks

[Tony Sade]

I use one of these from LV:

DMT DiaFlat™ Lapping Plate http://www.leevalley.com/US/wood/pag...17&cat=1,43072

(Mods-I can't remember if pointing a link to a merchant is acceptable. If not, pls. remove.)

LN sells the same one (I think it's the same) but it's a good bit pricier.

I leave it on my sharpening flat on one of those DMT no-slide mats and bring the stone to the plate. I started out doing the opposite, but after I dropped the plate and cracked a stone, I switched.

Almost forgot--I use the plate on the Sigma Power Select II ceramic stones, which I'm almost certain are man made (unless mother nature has devised a way to make ceramic materials herself), all the way up to the 13K. They work pretty fast, although I'm not to thrilled with the 240 which, IMO is not up to claims that it is good for for "rapid steel removal", especially when I have to create a primary bevel after some repair work on the grinder. I'm not good enough yet to grind down close enough to an edge to not spend way too much time on the 240.
HTH

[Sam Stephens]

my guess on the diamond stone is that it's loaded w/ debris and needs a thorough cleaning -mild abrasive detergent and a toothbrush. they typically take quite a long time to wear out and aren't supposed to dish. was the stone flat to begin with?

for flattening the back of plane irons, i usually don't use my diamond stones (seems wasteful to me). I use 120 grit sandpaper (from the automotive store) spray glued to glass and work my way up to 1000 grit. Only the 0.5-1" behind the sharp edge need to be flat. After the 1st flattening, it's touched up as needed to chase the burr but that's all.

not sure how you'd develop a slurry on the granite w/o some other abrasive???

[Chris Griggs]

Yes diamond stones wear out....not so much if you use them for flattening water stones but if you been doing heavy work on steal (e.g flattening back) you can wear out a diamond stone surprisingly quickly. This is why I only use mine for flattening waterstones, they are not inexpensive enough to be disposable.

If you want a cheap flat surface for flattening buy a granite floor tile from the BORG, or a piece of float glass, then get some loose silacon carbide grit and sprinkle a bit on the flat surface. SiC will flatten stones in a hurry...for flattening blades and soles, use 80-120 grit sandpaper instead of the SiC. Dare I admit that I've even used melamine shelves from the BORG for flattening large planes. That stuff can be surprisingly flat and if you put it on a solid surface (e.g. your workbench) and put some abrasive on it will work quite well (though a big piece of granite with known flatness would be preferable)

[Curt Putnam]

Atoma 400 used exclusively for stone flattening - as recommended by Stu. Works well and works fast.

[Noah Wagener]

Tony,

I seem to be using pretty much the same setup as you. My diamond stone is a DMT though not specifically called a lapping plate. It is labeled extra course which I believe is about 300 grit. Speed must be relative as I found the 250 grit water stone I just bought remarkably fast taking out a nick from hitting a nail with plane.
The diamond stone for dressing water stones seemed like the best and simplest option to me as there is no need to continually buying sandpaper. I also don't really have a flat surface to put glass on and think it would probably flex. Maybe i just got a lemon. I don't think it is loaded with debris Sam. Wouldn't rubbing waterstones on it remove any metal? It looks clean to me. And I am not sure if it was flat out the box as I just assumed so. I am not so certain if it got dished from sharpening or if the plate is bent. I noticed the problem because i glued rough sandpaper to the back to lap the sole of a block plane and noticed the scratch pattern was the opposite of the top. The bottom is slightly convex.
Anything i rub on the water stones (especially the soft one) creates a slurry of the grit that is being removed. I have a hunk of steel I am trying to scrape flat and rubbed the stone over it to see the high spots and it left a film of grit. Got me to thinking i don't need any kind of second abrasive.
Chris, I prefer to get my granite tiles from the Ferengi. Is granite something that can be made flat? The cut outs are pretty cheap. I know there is a method of using engineer's blue to mate to surfaces and if you can mate three then they must be flat. Two surfaces could match with, say one being a hill and one being a valley but a third surface could only mate with one of the first two. I just don't know how to remove granite.

thanks for help

[Steve Friedman]

Atoma 400 used exclusively for stone flattening - as recommended by Stu. Works well and works fast.

Yup. Not cheap, but neither are waterstones. If you're going to go to the trouble and expense of using waterstones, I think it makes sense to have a dedicated flattening plate so that the stones all end up with the same level of relative flatness. The Atoma is excellent.

Steve

[Adam Cruea]

Atoma 400 used exclusively for stone flattening - as recommended by Stu. Works well and works fast.

Another vote for the Atoma. Flattens my stones in a hurry.

[Tony Shea]

I use the same DMT stone you are to flatten your waterstones. My DMT is actually very flat but have had some that weren't. You must be picky when buying this stone.

My opinion is that you have dulled your diamond stone past the point of being useful by flattening coarse (250-400grit) waterstones and trying to flatten blade backs. My DMT only touches waterstones in the 800grit up range and never touches steel. That's just the way diamond stones are when you choose to use them to flatten waterstones. Supposedly the Dia-flat grit will last much longer but IMO is far too coarse of a stone to use on anything above a 1000grit waterstone.

I personally have used up a DMT xcoarse stone flattening a 400grit waterstone as well as using it on steel once and a while. I learned my lesson the hard way. I was very surprised how fast the 400grit chosera stone dulled the DMT and blame this for most of its wear. Now my coarse waterstones are flattened on sandpaper when they need it.

If I was buying another diamond stone to flatten waterstones I agree that the Atoma 400 is the best band for your buck and is what I'd buy.