Why not JUST diamond stones?

[Steve Friedman]

I like the DMT Duos better than the Diasharps. I find them to be flatter and just work better. The course/fine (red/blue) Duo would make a fine replacement for your 1000 stone, I believe. Just my opinion.

That's interesting. I never knew that, but DMT website seems to confirm that the Duo-Sharps are flatter. I have both and maybe that's why I haven't used the Dia-Sharps since getting the Duo-Sharps. But, I just ordered the XX Coarse 120 grit Dia-Sharp to flatten backs because the Duo-Sharps don't come that coarse. How do you check a diamond plate for flatness since the surface isn't smooth? I see that DMT will replace any of their products that are not flat.

Thanks,

Steve

[John Coloccia]

That's interesting. I never knew that, but DMT website seems to confirm that the Duo-Sharps are flatter. I have both and maybe that's why I haven't used the Dia-Sharps since getting the Duo-Sharps. But, I just ordered the XX Coarse 120 grit Dia-Sharp to flatten backs because the Duo-Sharps don't come that coarse. How do you check a diamond plate for flatness since the surface isn't smooth? I see that DMT will replace any of their products that are not flat.

Thanks,

Steve

You just have to do your best and maybe even just eyeball it. Your eye can be pretty accurate at detecting deviations from straight. The Diasharp I have is far enough out of flat that I can easily eyeball the warp. I suppose I should have it replaced but I never got around to it.

[David Weaver]

I also like the duos over the diasharps - I don't know how many duosharps i've come across, maybe 4 (I pushed them on other folks who were using sandpaper to flatten their stones, when I could find a duo with one of the sides at 325 grit for $55 on amazon). Every single one of them has been dead flat.

To use diamond stones only and then find out that you got one that is 4 thousandths hollow, and find out the next is 4 thousandths proud would create a lot of extra work flattening backs of tools - though it wouldn't really affect anything else if you microbevel or hollow grind.

I never found great favor in their feel or the way they cut deep narrow grooves. My experience with the finer ones is that when the diamonds start to dull some, they still cut a bevel well, but if you put a big flat surface on them, like the back of a chisel, you are forced to apply more pressure than you'd like to, which only speeds up the process of them becoming more marginal.

As a bevel sharpener and a stone dressing tool, though, they're great, and nice to have around for sharpening things that would put a rut in ceramic or waterstones.

[David Weaver]

The Diasharp I have is far enough out of flat that I can easily eyeball the warp.

I have two generic copies of koyama hones that were called "XL Sharp" or something that are also out of flat, and can see it. I could see it immediately after taking them out of the package and sighting them. They are at most out about 3 to 4 thousandths over 4 inches, but it's enough to cause problems with them flattening things. If I couldn't see deviation sighting them, then I probably wouldn't worry about them, either

[Jim Belair]

Thanks for all the input. The fact that they may not be all that flat and that they do wear out pretty well blows both my points out of the water! I had hear that one needs to go easy on them and that the feel changes from initial. The ability to renew a waterstone to original performance until it is used up has some merit.

I'll stick with my coarse DiaSharp for edgeshaping and stone flattening and leave the waterstones to sharpening.

Cheers
Jim B

[george wilson]

It is a bit problematic determining the flatness of the metal diamond stones. They are wrapped in plastic when you pick them out. Even when you take them out of the plastic,a straight edge doesn't rest flat on the stones,because the diamonds hold it up off the metal. As was said,it is mostly an eyeball gauge process choosing one.

[Andrae Covington]

Thanks for all the input. The fact that they may not be all that flat and that they do wear out pretty well blows both my points out of the water! I had hear that one needs to go easy on them and that the feel changes from initial. The ability to renew a waterstone to original performance until it is used up has some merit.

I'll stick with my coarse DiaSharp for edgeshaping and stone flattening and leave the waterstones to sharpening.

Cheers
Jim B

I only use diamond stones. I have DMT Dia-Sharp 8x3 plates in Extra Coarse (60 micron), Coarse (45 micron), Fine (25 micron), Extra Fine (9 micron), and Extra-Extra Fine (3 micron). I sometimes use green compound on a leather strop.

My experience aligns with what Sam Takeuchi and David Weaver have said. Fortunately most of mine are quite flat, but a couple are a little off. The real problem is the degradation over time, which I unwittingly accelerated by doing a considerable amount of flattening the backs of chisels and blades, and pressing too hard. My Extra Coarse and Coarse stones in particular cut much, much slower than they did at first. The other stones are slower than they used to be, but not that bad.

It is the only system I have used, other than occasional sandpaper on granite tile. I wanted to avoid the near-constant flattening process of water stones, which sounded like a real hassle to me. But slogging away on worn-down diamond stones is a hassle, so I'm not sure I did myself any favors. As any quality choice of stones is expensive, I am reluctant to now shell out more for a set of water stones, oil stones, fire stones, etc. So I keep using what I have.

[Terry Beadle]

I have a DMT coarse/extra course and it's almost flat. I've used it for about 5 years. I did use it on some chisel/plane blade flattening but only for a little bit as I was apprised on this site of the need to only use it on the stones. It's still working fairly well. I use the extra course on stones of equal to or less than 1000 grit. I use the coarse side on stones above 1000. I find that the higher grit stones stay cleaner and flatter longer by the use of the coarse instead of the extra course. Probably my perception vs reality, but there it is.

This diamond stone is wearing, albight slowly. I do wish it was flatter but I make sure it's cleaned and dry and stored flat. Over the years this has helped the DMT to be flatter ( not by much ).

IMO the only thing you gain by using diamond stones to flatten water stones is the speed. If you use a same grit or slightly less grit water stone on a water stone to flatten them, you bag both in one effort. Therefore, IMO, you don't need the diamond stones but they are nice to have.

I notice Rob Cosman only uses another water stone to flatten another water stone and from the looks of his jointery, they must be working great !

In short, Mr. Covington, Mr. Weaver, and just about every one that's posted to this thread are right. A Diamond Stone has it's uses but it's not the every thing.

[Steve Friedman]

Has anyone used diamond paste to "recharge" a worn down Dia-Sharp? Just wondering.

Steve

[David Weaver]

Not yet, but there should be some merit to it if the plate is soft enough that whatever you sharpen on it will push the diamonds into the plate.

No clue how hard the surface of a beat DMT is.

Even better would be loose diamonds so that you don't have the lubricant discouraging the diamonds from digging in and putting a layer of lubricant between the iron to be sharpened and the beat diamond hone.

[Steve Friedman]

Thanks David,

Short of asking my wife to lend me some, where does one get loose diamonds? Are they sold in micron sizes? Also, without lubricant, don't they just roll around?

Steve

[David Weaver]

On ebay is the cheapest I've been able to find. Lapidary supply places sell them to folks who go through a lot more than we would sharpening things, so they're surprisingly cheap.

There are sellers on ebay who label in grit size and micron size and basically sell for somewhere in the ballpark of 25 cents per carat of diamond weight.

In terms of the diamonds rolling around, what you're doing when you deal with loose diamonds is finding a substrate that is soft enough for the diamonds to embed, but hard enough to keep them pointed in a direction that they can do damage, and hard enough to wear well. The result should be the same regardless of lubricant. In the case of something like cast iron as the substrate (instead of a diamond plate), the hardened plane iron will smash the diamonds into the cast iron and they will stick in it. Once they're stuck in it and in a stationary position, the bits that stick out of the cast iron will scratch the hardened iron, regardless of lubricant.

See item (on ebay):
320704507255

No affiliation to the guy/girl who sells them, just telling you where to get diamond powder the cheapest. I've purchased from him twice and found the diamonds to be just fine. You can fish around through their store to find the grit you want. No clue if finding 600 grit and throwing them on a DMT 600 grit side will give you comparable results to original. I use the loose diamonds only for flattening very poorly treated chisels and irons, and in something along the lines of 100-120 grit.