DMT Duo Sharp OR Dia Sharp?

MTHall720

MTHall720

Joined
Sep 21, 2010
Messages
2,957
Not sure which of these is the better choice. Will be sharpening folders and fixed up to 7 inches.
I recently bought another new Sharpmaker but feel confident about moving on. Before I sell or grade it I just want to be sure I am making a good choice about which of the DMT to get.

Thanks very much.
 
I prefer the diasharp, the continuous surface works better for me than the duosharp's broken surface. For flattening waterstones, on the other hand, the broken surface works better by preventing stiction.
 
Thanks for your input on this. I don't have water stones and will be looking at this as my only method of sharpening.
 
Both are good, but the Dia-Sharp (continuous surface) leaves a more uniform finish, which makes perfect sense when you think about it. The interrupted-surface hones (Duo-Sharp) can leave a somewhat wavy finish on an edge, especially if used with excessive pressure. And there aren't any worries of damaging a blade tip in a 'dimple' on the Dia-Sharp continuous hones, as with the Duo-Sharp hones. And the extra diamond surface area of the Dia-Sharps will put that much more diamond in direct contact with your edge, which means it'll work faster. If you can afford the Dia-Sharp hones, I think they give more bang-for-the-buck. I keep hoping DMT will make a continuous-surface version of the Dia-Folds. Those would be great. ;)
 
It's really weird how DMT markets the diasharp versus duosharp. DMT *says* the duosharps sharpen faster than the diasharps. There are a few threads here on BF about this. It makes no sense to me though: The diasharps have more abrasive material per square inch than the duosharps, so how can the duos be faster grinders?

At least one BF member chimed in on a previous discussion about this saying that he agreed that the duosharps were faster. I can't comment from experience as I only have the diasharps. Pretty much everyone on BF that talks about DMT talks about diasharps, including most of the people that seem to *really* get sharpening. So I just went with what they said worked well.

I've been happy with my DMT diasharps, but I keep wondering if waterstones might work better for some of what I work on. I guess it could be worse: I could have more expensive hobbies. :)

Brian.
 
(...)DMT *says* the duosharps sharpen faster than the diasharps. There are a few threads here on BF about this.
Click to expand...

bg, this makes no sense to me either.

I keep hoping to actually see a site link from DMT directly, where that claim is made. I have seen them claim that the Duo-Sharps are faster than 'other hones' or 'other conventional hones' (both very non-specific, and might be mis-interpreted to imply the Dia-Sharps). But, I have never been able to find such a claim, directly from DMT, that they're faster than the Dia-Sharps or DMT's continuous hones, specifically by name. I keep reading hearsay or secondhand posts about this here on BF, but have never seen a direct quote (directly linked to DMT) included. I think DMT is much smarter than to make such a claim, and I personally don't believe it, when comparing two hones of equal dimensions with exactly the same type of abrasive, and claiming that less of it, on one hone, is actually faster. Makes no sense whatsoever. And, more importantly to me personally, after having used both types, I've repeatedly proven to myself it makes no sense.

DMT has claimed that the interrupted hones can speed honing generally, based on how the swarf is (supposedly) collected in the dimples on the hone, which is supposed to keep the hone from loading up. I can believe that to some limited extent, though the interrupted hones still clog up too; I've done it. This swarf-collecting 'advantage' of the dimples can essentially be rendered moot though, if one just uses some form of suspension medium (water, oil) to keep the swarf from settling into & clogging the hones (or just periodically spritz with some Windex & wipe off the swarf, as I do ;)).
 
Diasharp for me. Continuous surface trumps a broken one every time for me. For me its more about how the blade feels on the stone and I feel like I get a truer feedback from the diasharps.
 
I think that most people here use the diasharps. I use the duosharps. I love them. Diamonds cut fast either way. I have noticed that the swarf falls into the little holes, and the blade goes over the stone quickly due to the interruption. Maybe that's what makes them faster? I dunno. I use the XC and C dry, so that might make a big difference at the coarser grits. I use water on the F, XF, and XXF stones, so maybe it makes less of a difference? One thing is certainly true: the duosharps are manufactured precision flat. The diasharps are not. You can find plenty of testimonies online (even here on BF) where people have noticed that their diasharp stones are not quite flat. But yeah, besides me, you will not find a lot of love for the duosharps here on BF. I'm sure that if I tried the diasharps, I'd like them, too. Ultimately, it's about the sharpening technique more than the medium or even the flatness/evenness of the stone. A good set of bench stones, whether diamond or water or ceramic, will definitely do the job faster and with more pleasure than sharpening on, for example, a cinderblock and a brick (which you can do).

That said, I don't like all the hate against duosharps here. It's not a plot by DMT to give you fewer diamonds (some people think that's what duosharps are about). And I have never, ever heard of anyone getting a wave pattern or some other error on their edge by using the interrupted stones. I get fantastic, perfectly even edges with my duosharps, never any problems at all. And I've never heard of anyone getting a wave pattern or some other problem on their edges with a duosharp stone. I'd like to see pictures if someone is making that claim. In short: either one will certainly serve you very well.
 
I don't see any 'hate' against the Duo-sharps, at least in the Maint forum. For those of us who've actually used both types, we've all been able to see the real differences between them. For me personally, I have four (4) of the interrupted surface hones from DMT (one Duo-Sharp bench hone, three Dia-Folds), and five of the continuous hones (two double-sided 6" x 2" hones, 2 'credit card' hones, and one 4" pocket hone). They all work very well, albeit with differences in performance. I have no regrets about buying any of them. I just think the published 'advantage' of the dimpled surface slowing the loading up of the hones is over-hyped, and doesn't offset the advantage in cutting speed (not how fast the blade skates over the hone, which is meaningless by itself) or the more uniform finish left by the continuous hones.
 
Thanks very much to everyone for the information. I always learn a lot here. Just wondering if a 6x2 stone would cover almost all folders I have (none over 5.3 inches) and maybe up to 7 inch fixed. Do Diasharps come in the two sided version the same as Duo Sharp?
 
MTHall720 said:
Thanks very much to everyone for the information. I always learn a lot here. Just wondering if a 6x2 stone would cover almost all folders I have (none over 5.3 inches) and maybe up to 7 inch fixed. Do Diasharps come in the two sided version the same as Duo Sharp?
Click to expand...

Yes, they do. That's what I have, the 6" x 2" double-sided Diasharp hones in XC/C, F/EF (links below; Knifecenter is a BF member). In terms of size, I'm sure those will do fine for folders (great, even). I do most of my folders on my smaller hones, more often than not (Dia-Folds w/my Aligner/Magna-Guide, and also my credit card hones).

http://www2.knifecenter.com/item/DM...a-Sharp-Continuous-Diamond-CoarseExtra-Coarse
http://www2.knifecenter.com/item/DMTD6EF/DMT-D6EF-6-inch-Dia-Sharp-Continuous-Diamond-Extra-FineFine
 
Obsessed with Edges said:
... or the more uniform finish left by the continuous hones.
Click to expand...

I know that you have a lot of experience sharpening, and I've read all of your threads on sharpening with great interest, so I respect your opinion on equipment a lot. But I don't see what you mean about wave patterns on the edge or a non-uniform finish left by the duosharp stones. Do you have pics to illustrate what you mean? I have never had that problem, and I've never heard of anyone else having that problem.
 
Magnaminous_G said:
.. Do you have pics to illustrate what you mean? I have never had that problem, and I've never heard of anyone else having that problem.
Click to expand...

I mentioned about this problem a few times before...



Image of Duosharp 8" CF, notice those lengthwise bright-lines are raised-surface, so if the blade strokes perpendicular to the stone, will result in banded scratches from spine to edge. I've a diafold EF/EEF, it is almost uniformly flat.
 
Any surface used for sharpening, if it isn't consistent in hardness and abrasiveness across the entire length and width of it's surface, has the potential to cut or abrade unevenly. The interrupted surface hones, as the name implies, feature diamond abrasive embedded in nickel, over steel, and 'interrupted' by the recessed dimples of plastic/synthetic material, which obviously won't be cutting or abrading anything at all. Now IF one's technique is sound, and pressure isn't excessive, and care is taken to sweep a blade down & across the hone, so that at one time or another all portions of the edge are contacting the abrasive surface in a consistent manner, the finish left on the blade can and will be good. IF, on the other hand, pressure is a little too heavy (and this is easy to do on diamond), or the stroke direction inconsistent or less-than-optimum, not all of the blade edge is going to get the same exposure to the abrasive. This is how an uneven finish comes about. My point in all this, is that the fully uniform surface of the continuous hones is much more tolerant of differences in stroke or pressure, simply because the edge is always, always in contact with the same abrasive on the same substrate. The simplest way to illustrate this is to take a blade with a flat, straight edge & bevel (like a chisel, for example) and make one linear straight-ahead pass on each of the interrupted and continuous hones, and look at the difference in the grind pattern left. The differences are easier to see at higher grit levels especially, where the inconsistent 'shine' in the resulting bevel will more easily show the imperfections. This isn't to say the finish left on the interrupted hones is a problem, and less so if one's technique is good. It's just that it becomes much more obvious, when compared side-by-side to the finish left on the continuous hones, all other factors being equal.

Edited to add:
The uniformity of the continuous hones can even be felt under the fingertips, when sharpening on them. The fine/EF hones, especially, feel buttery smooth under a blade, as contrasted to the slight 'bumpy' sensation felt when sharpening across the dimples on the interrupted hones. This was the immediate and most striking difference I noticed, when first trying out one of the continuous hones. And if your fingers can feel it, the steel will be 'feeling' it too.
 
Last edited:
Obsessed with Edges said:
My point in all this, is that the fully uniform surface of the continuous hones is much more tolerant of differences in stroke or pressure, simply because the edge is always, always in contact with the same abrasive on the same substrate.
Click to expand...

You mentioned that good technique will get good results on the duosharps but the diasharps are more forgiving, so I guess that clarifies what you meant. In your first posts, it sounded like you were implying that the interrupted surface itself would give bad results. That's what I took issue with since I never had any problems with bad results, wavy edges, etc. Thank you for clarifying.
 
You must log in or register to reply here.
Back
Top