Is it wrong...

[Phil Stone]

to use the same diamond stone (e.g. the 8" DMT Dia-Sharp) for grinding primary bevels AND flattening water stones?

I've searched the archives and become more confused. Recommendations, please (and thank you).

[george wilson]

I have done it.

[David Barnett]

I've done it, too, and recommend it.

[paul cottingham]

Done it as well. I usually grind primary bevels on my 8" grinder, but the diamond stone works great when I don't have the nervous energy and focus for using power.
Works great.

[Steve Friedman]

I hate to disagree with the opinions of those whom I respect, but I'm going to respectfully disagree and say that it's a mistake to use the same diamond plate to flatten stones and work the steel for two main reasons.

First reason is that I spent a lot of money on my water stones and, because I use a honing guide, they're useless unless they're completely flat. That's why I spent a lot of money on some Atoma diamond plates to keep the water stones flat. Given that investment, I'm not willing to do anything that will wear my Atoma water stones prematurely or make them go out of flat. Especially when there are (IMHO) better and cheaper ways to grind primary bevels. The surface of the primary bevel isn't going to touch the wood anyway, so the method you use to establish it is less critical than the method you use to establish the final secondary or micro bevel.

Second reason is actually something I learned from David Barnett around a year ago. The monocrystalline diamonds used in most diamond plates are great for flattening water stones, but polycrystalline diamonds are better for abrading steel. The only one I know of it the EZE-Lap, which apparently is now a blend of the two types.

Just my experience.

[Winton Applegate]

in this case I am going to do the rare thing, for me, and go with the majority. Mark this one on the calendar cause it doesn't happen often.

Mono vs Poly for steel

That’s an interesting one. I think we were “told” the mono is better. Better for what ? Well the ads / info from the mono guys say its better. For every thing.

I don’t know about which is best for steel. Guessing I would say mono lasts longer and poly may cut faster until it fractures away.
But that’s not the topic here.

Here are my experiences:
Flattening A2 plane blade backs wears the diamond stones WAY more than flattening WATER STONES.

Taking a blade up on edge, perpendicular, say, to get rid of a pit or what I did more recently . . . I took the double bevel off my two swiss army knives and put on single bevels one right and one left. Now that kicked the crap out of the diamond plate and I gave up early when I saw how it was going and just touched the edge on my white stone on my medium speed power grinder. It said “zip” and the edge was gone. Jusssslahtha. Then I did the second one on the power grinder.

Another thing that kicks the crap out of the diamond plates way more than flattening WATER STONES and that is flattening HARD ARKANSAS STONES.

So
my experience with flattening WATER stones on my diamond plates is that since I am using the WHOLE surface practically simultaneously and since the WATER stones are so friable and since I keep the stones pretty flat all the time so it takes hardly any time on the diamond plate to correct the stones.
I find
in actual practice
over years and years
that water stones make almost no wear on my diamond plates and so I can get great results sharpening blade bevels on them AND flattening water stones.
I wouldn’t worry about it in the least.
Hard ARKS now . . . that is a whole another affair.

PS: maybe if you have hard stones like the ceramic stones you might get to wearing the diamond plates, I used mostly Norton water stones and more recently Shapton Pro stones. I also flattened the huge pink flattening stone (because when I got it it wasn't flat enough) and that was / is NOT a big wear on the diamond plates either.

[David Barnett]

Second reason is actually something I learned from David Barnett around a year ago. The monocrystalline diamonds used in most diamond plates are great for flattening water stones, but polycrystalline diamonds are better for abrading steel. The only one I know of it the EZE-Lap, which apparently is now a blend of the two types.

Steve, my bad.

When the OP asked his question I'll have to admit I wasn't thinking that out of flat or uneven wear on the diamond plates might produce a less flat waterstone. Some diamond laps and plates these days are very flat indeed. My prejudices and habits are apparent when I'll further admit I was thinking more about waterstones not causing deleterious effects to a diamond plate.

When asked how to flatten a waterstone, I've often casually suggested using one's diamond plate, whether mono or poly, and still think using one's polycrystalline tool sharpening plate, broken-in and evenly worn, should pose no problems. Perhaps my expectations for waterstone flatness fall short of your own, however. and will defer to your experience.

When I bought my waterstones they were actually cheap, even the naturals. They worked well, too, but I personally found them fussy to use and maintain, so when I found diamond, I just never gave them nearly as much thought again, and probably less than they deserve in their more recently available forms. As I use diamond so freely and extensively for so much—gem faceting and carving, cold-working cast glass, jewelry work, toolmaking, sharpening gravers and woodworking tools—I've likely become slapdash and dismissive of practices and preferences I no longer share.

While I still prefer my older EZE-laps to my newer, they're all good.

[george wilson]

I flattened my 2 Spyderco ceramic stones on our solitary diamond stone,and we continued to use it for years afterwards. I did not use much pressure on the ceramic stones when rubbing them against the diamond,under the water faucet. Technique surely has something to do with the longevity of your diamond stones.

By the way,I'll repeat my warning to water stone users to NOT keep flattening your stones in the kitchen sink: The slurry will settle in your pipes,and will not ever go away. Water stones make a lot more mess than a single flattening of a slightly off of flat ceramic stone. And,you repeat it regularly. Once flat,my ceramic stones were DONE,permanently.

David B.: If you can find an old sandstone wheel,even a broken one,it will very efficiently flatten even hard,black arkansas stones. Lay the sandstone on its side,pour on water a lot,and rub the Arkansas on it. You might could get a piece of sandstone at a stone dealer's place. I learned that trick from a very old English cabinet maker in the early 70's. Remarkable how the old timers found ways to get along with nearly nothing. They certainly did not have diamonds!! They threw heather on steel plates they were running orange hot through rolling mills. It crushed and exploded as it went under the rollers,blowing the scale off the steel to keep the scale from printing into the soft,hot steel. Today,we use very high pressure jets of water,but they didn't have that back then. Queen Victoria recalled the constant exploding heather after she visited a steel mill in the 19th. C..

Speaking of that: A friend of mine wanted a block of soapstone to sculpt. The art supply places want a fortune for a block,while you can get a nice block for a fraction of their price at an architectural stone dealer. Builders can't afford to pay $50.00 for each little block of soapstone in a building (or whatever they use it for!!)

About waterstones on diamond plates: The waterstones are making a very large contact surface on the diamond plates. That means a LOT less localized pressure on the diamonds. As for hardness,there is a vast difference between the hardness of the diamonds and the waterstones. Vast. The main thing is to not dislodge the diamonds. And,large footprint helps greatly in not dislodging the diamonds.

When you press a steel cutting edge on your diamonds,you are presenting a single line of contact. That will go a very great deal further towards dislodging the diamonds. Bear down very lightly. Not only the dislodging problem,but diamonds are exceedingly brittle. Another excellent reason to bear down very lightly on them.

[Daniel Rode]

to use the same diamond stone (e.g. the 8" DMT Dia-Sharp) for grinding primary bevels AND flattening water stones?

I've searched the archives and become more confused. Recommendations, please (and thank you).

This is exactly what I do. I get sharp irons and chisels, so I've stuck with it.

[John Coloccia]

I use a DuoSharp to establish bevels and flatten stones. I flatten the stones after every 20 or 30 seconds or so. Much easier to keep it flat than make it flat

I tried a Diasharp, but I could never seem to find one that was actually flat. My DuoSharp is dead flat.

[Robert Hazelwood]

I don't really think it's bad to use the diamond stones for both purposes...as long as you don't use too much pressure when grinding the primary bevel they should be ok. High pressure sharpening on a coarse diamond stone could damage them.

However, if I had to grind a primary bevel by hand I would rather use very coarse sandpaper stuck to something flat than any of my diamond stones. A fresh sheet of 60 grit paper cuts way faster than my coarsest diamond stone (DMT X-coarse, which is 220 grit I think). Diamond stones definitely have advantages for ease of maintenance and grinding exotic high-carbide steels (which are rarely seen in woodworking), but I've never found them to be particularly fast cutting compared to sandpaper or waterstones.

[David Weaver]

to use the same diamond stone (e.g. the 8" DMT Dia-Sharp) for grinding primary bevels AND flattening water stones?

I've searched the archives and become more confused. Recommendations, please (and thank you).

Not adding anything new to the discussion -you can use a diamond hone for both. If you want the diamond hone to cut the stone fast, though, it's best to set at least one side of a double sided hone or something aside to use it only for flattening stones.

[Steve Friedman]

Part of my comments above come from the discussion a year or two ago about the fact that folks were complaining that the Sigma #400 stone was causing their Atoma #400 diamond plate to wear very quickly. There was also complaints about how long it was taking to flatten that stone. After e-mailing Stu, I decided to add an Atoma #140 diamond plate just to use for the Sigma #400 stone. It was amazing. The Atoma #140 flattened the Sigma #400 is a fraction of the time and, as an added benefit, made the stone even more aggressive that it was coming off the Atoma #400 plate.

I have since found lots of uses for the Atoma #140. For example, I bought a set of Spyderco ceramic stones to use for my carving gouges. They were not even close to flat. I used the Atoma #140 (following George's advice to do it under running water) to flatten them and it worked like a charm. I can't imagine how long that would have taken with a higher grit diamond plate.

I haven't tried the newer DMT Dia-Flat, but before using water stones, I used to sharpen with DMT diamond plates (Dia-Sharp and Duo-Sharp) and a strop. I found that the plates were not flat and definitely wore out unevenly. I readily admit that part of it may have been my fault for using too much pressure. To preserve my Atoma plates, I bought some EZ Lap plates just to use for abrading steel. They're cheap and work, but these days just sit on a shelf. For the lower grits (80 - 220) I now use exclusively sandpaper on granite. It's quick and easy. I love the 3M Gold PSA sandpaper. It's pricey, but I think the A-weight paper leads to less chance of dubbing and the adhesive leaves absolutely no residue. In my experience, nothing flattens backs better and nothing (without resorting to power) is better to establish a primary bevel.

Steve

[Phil Stone]

I use a DuoSharp to establish bevels and flatten stones. I flatten the stones after every 20 or 30 seconds or so. Much easier to keep it flat than make it flat

I tried a Diasharp, but I could never seem to find one that was actually flat. My DuoSharp is dead flat.

Hi John, thanks for the reply. I just ordered a Course/Extra Course DuoSharp; do you use one side for bevels and the other for flattening stones, or do you use both for both?

[John Coloccia]

Hi John, thanks for the reply. I just ordered a Course/Extra Course DuoSharp; do you use one side for bevels and the other for flattening stones, or do you use both for both?

I think I have the Course/Fine....red/blue, whatever that is. I use the coarse side for everything, actually. I think you'll find that once you've flattened your stones, if you just keep them flat by flipping the stone around every few stroke, and then flattening very frequently (every 20 seconds or so, maybe), the flattening process just takes a couple of seconds, the wear on everything is less, and the entire process becomes headache free. That's just my opinion.