DMT Diasharp: The "Final" Thread

[John Frankl]

First, please let me thank the many knowledgeable and helpful people on this forum.

Next, let me say that I am something of a stone collector. I have plenty.

Last, I would like to get a "difinitive" set of DMT Diasharps. And I would greatly appreciate any help all of you can provide with the following questions.

1. What is the best internet source?

2. For all kinds and sizes of knives, do you recommend the 8x3 or the 11.5x2.5?

3. What grits should I have?

Thanks,

John

 

[nozh2002]

1. I think NG now have thosue stones.
2. 11.5" better for knife blades, 8" is better for chisels.
3. I need only 120 extra extra coarse (exist only in 8" stones), Coarse and Extra Fine, following up with Chromium Oxide paste, I found that there is not difference between Extra Extra Fine and Extra Fine.

Thanks, Vassili.

 

[sodak]

1. Don't know. I got mine from DMT, at the time, they were kind of hard to find.
2. The bigger the better.
3. I use the blue and red BY FAR, the most. Black I use when there's some serious damage, otherwise I use a belt sander.

 

[Jason B.]

I get my DMT products here http://www.knifecenter.com/knifecenter/dmt/


The 8x3 IMO are just the right size, its also the only size that has the XX-fine. I'm a bit of a stone collector myself and of everything I have I like the diamonds the most. The complete set of 8x3's are what you want but to start you can get the X-coarse, fine, X-fine, XX-fine and be good until you feel like getting the others. At first the fine DMT stones will feel very coarse but they will break-in eventually and work VERY WELL. Don't forget about strop compounds either, diamond compounds cost more but are more than worth it. I was going to give a link to to the best diamond compound http://www.japaneseknifesharpeningstore.com/default.asp but they don't have it anymore . A good second choice would be this stuff thought http://www.classicshaving.com/catalog/item/522944/482854.htm

And to think I still need more stones

 

[gary jp4]

Craftsman Studios is also a good place.

 

[THG]

I found that there is not difference between Extra Extra Fine and Extra Fine.

I agree. I don't do the whole XXC --> XC --> C --> F --> EF --> EEF thing. I don't believe in it. The coarsest stone I have is XC, and I go right from that to F, and I'm done. IMO, C in between is unnecessary; F gets rid of all the deep XC scratches in a matter of minutes anyway. I don't have EF or EEF, but if I were to get one, I would just go with the EEF for a system of XC --> F --> EEF

 

[bonesthedog]

Should I get combo diasharps, or the single grit ones? What's the advantage to a single grit vs a combo diasharp?

 

[nozh2002]

I agree. I don't do the whole XXC --> XC --> C --> F --> EF --> EEF thing. I don't believe in it. The coarsest stone I have is XC, and I go right from that to F, and I'm done. IMO, C in between is unnecessary; F gets rid of all the deep XC scratches in a matter of minutes anyway. I don't have EF or EEF, but if I were to get one, I would just go with the EEF for a system of XC --> F --> EEF

It is simple to understand knowing abrasive sizes:

Silver XX Extra Extra Coarse 120 120
Black X Extra Coarse 220 60
Blue C Coarse 325 45
Red F Fine 600 25
Yellow E Extra Fine 1200 9
Tan EE Extra Extra Fine 8000 3

There is no practical difference between 120 microns and 60 or between 25 and 9. I also have other grids but finally came to those three and see no reason to waste time going through all existed grids (until it is just showing respect to your collection of course).

Problem with EE - it not too much different form E and it is only 8" which way less convenient then 11.5" especially for blades longer then 4". And anyway I use Chromium Oxide after diamonds.

Thanks, Vassili.

 

[Jason B.]

Vassili, use that EE some more there is a big difference from the E. Mine didn't really break-in until I tried sharpening a ceramic knife.

 

[nozh2002]

If you need 6 months and ceramic blade to bring it to work condition - it is too much for me. As well as I do not see why should I do this with less convenient stone size while my current solution works just fine.

Thanks, Vassili.

 

[Jason B.]

Because your knives would be sharper in the end.

 

[Josh K]

If you need 6 months and ceramic blade to bring it to work condition - it is too much for me. As well as I do not see why should I do this with less convenient stone size while my current solution works just fine.

Thanks, Vassili.

The whole idea is to create a smoother scratch pattern. If you're going straight from course to extra fine, you're probably not refining the pattern as much as if you went course -> fine -> extra fine -> EEF.

All sharpening systems need a break in period.

Also, chromium oxide may not be the best for harder (S90V/S110V) steels with carbides.

 

[nozh2002]

Because your knives would be sharper in the end.

So far I did not see knives sharper then what I can do.

The whole idea is to create a smoother scratch pattern. If you're going straight from course to extra fine, you're probably not refining the pattern as much as if you went course -> fine -> extra fine -> EEF.

I am for sure have it refined just perfect - no any "probably" here. It is easy to check with microscope. This is just waste of time.

6 month break period? No thanks.

CPM S90V and CPM S110V does recuire diamond powder, but not 3 micron - this make no much difference.

Thanks, Vassili.

 

[THG]

The whole idea is to create a smoother scratch pattern. If you're going straight from course to extra fine, you're probably not refining the pattern as much as if you went course -> fine -> extra fine -> EEF.

You'll get as much of a "refined" pattern; it'll just take a bit longer. IMO if you're going from XC to C to F to EF, and say you finish there, then you're wasting metal in the "in-betweens." If you go from XC to C, then you spend time and metal getting the scratches to be size "C," if you will. Then you go to F and spend more time and metal to get a complete "F" scratch pattern, then EF, etc. If you go straight from say XC to F, then you don't waste that metal at C, and it shouldn't take all that much longer to make the F pattern complete coming from XC.

That's how I see it, anyway; that's my method.

 

[Josh K]

You'll get as much of a "refined" pattern; it'll just take a bit longer. IMO if you're going from XC to C to F to EF, and say you finish there, then you're wasting metal in the "in-betweens." If you go from XC to C, then you spend time and metal getting the scratches to be size "C," if you will. Then you go to F and spend more time and metal to get a complete "F" scratch pattern, then EF, etc. If you go straight from say XC to F, then you don't waste that metal at C, and it shouldn't take all that much longer to make the F pattern complete coming from XC.

That's how I see it, anyway; that's my method.

By the same rational you should skip it all and just strop, or at the most, just go to EEF and take a while doing it.

 

[Jason B.]

Can you see the difference now?

X-Fine

XX-Fine

XX-Fine with outdoor lighting

 

[nozh2002]

Yes, scratches goes in different direction and first picture zoomed up 20%.
But after Chromium Oxide I have mirror surface without any scratches at all (at least under microscope I do not see it).

Thanks, Vassili.

 

[Josh K]

Yes, scratches goes in different direction and first picture zoomed up 20%.
But after Chromium Oxide I have mirror surface without any scratches at all (at least under microscope I do not see it).

Thanks, Vassili.

I'm seeing a mirror edge after just the EEF stone.

Here's what I'm thinking. You're scratching off metal. Now these scratches on the course stones are deep and ugly. Jumping to a much higher stone (EF) will give you polished course scratches. Moving sequentially across the grits will give you a finer and finer scratch pattern, and then when you strop, you're not going to have mirror topped scratches, but a pure mirror edge.

 

[Jason B.]

Sorry about the zoom here are the ones I should have posted. Is the direction of the scratches really that big a deal? Why are you trying so hard to not believe the facts? You don't think jumping from 9 microns to 0.5 microns is too much.

 

[THG]

Moving sequentially across the grits will give you a finer and finer scratch pattern, and then when you strop, you're not going to have mirror topped scratches, but a pure mirror edge.

I disagree. If you spend enough time on the finer grits, you'll eventually get all the way to the bottom of the deep scratches anyway. It might take a little bit longer, but you'll get there, and you'll have removed less metal in the process.