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Sharpening with diamond plates

Mon Nov 05, 2012 11:24 am


I really want to learn how to sharpen knives on water stones, but as I work in a busy kitchen I don't have any time to sharpen my knives, could you give some suggestion on how to sharpen knives on diamond stones, what's a good progression on them? A friend of mine prefers diamond stones and he gets really good results, he uses DMT coarse, fine and extra fine, is this a good progression or shoul I go further and use DMT XX Fine and finish it on a strop? I got a ZPD189 gyuto from my father, it needs sharpening but I want to do it by myself. I know I can ruin the knife, I may start sharpening a cheaper knife before this expensive knife, for practicing.


Re: Sharpening with diamond plates

Mon Nov 05, 2012 11:37 am

Hi Serg,

Diamond plates will add speed to your sharpening and they're convenient in that they never dish and cut every kind of steel. My suggestion is to use one for metal removal and then switch to stones for the rest of the job. You will also get lots of use out of the dmt plate for flattening your stones. Shapton Glass stones are fast cutters, easy to use, light and convenient. They also don't require any soaking. So if it were me I would do something like this:

Shapton Glass 500
Shapton Glass 1K
Shapton Glass 6K

Do not learn to sharpen on your ZDP189 knife. Learn on a beater and sharpen until you get the hang of it and then sharpen the ZDP189 knife. You don't want to mess it up.

I did some videos on sharpening that you may find helpful here:

Whatever you choose please come back and ask any follow up questions. I'll be happy to help.

Re: Sharpening with diamond plates

Mon Nov 05, 2012 12:32 pm

After getting the knife sharp, should I maintain it with a strop or a polish steel rod?

Re: Sharpening with diamond plates

Mon Nov 05, 2012 7:18 pm

Do not use a steel or ceramic on ZDP, the steel is too hard and you will chip the edge.

Diamonds can be used but only with some steels, the steel needs to have both hardness and wear resistance to benefit from using diamond hones. Using diamonds on carbon or low alloy stainless can be done but at full hardness and ground thin on a quality blade the diamonds become too aggressive and tear at the metal causing the edge to be prone to problematic burrs and failure in use.

Re: Sharpening with diamond plates

Tue Nov 06, 2012 8:27 am

I'd like to mirror Mark's suggestion to go with the GlassStones over a set of DMT plates....especially for that knife. ZDP is typically hardened to a very high HRC. Diamonds and extremely hard steel don't mix....lots of microchips in my humble experience. Stone's wear away the steel, diamonds rip it away...best way I can think to describe what I experience.

Hahah.....I hadn't read Jason B.'s comments. Errr, sorry for doubling up. :)

Maintain with a loaded strop or (my preference) your highest grit stone.

Re: Sharpening with diamond plates

Tue Nov 06, 2012 1:47 pm

I've lately been touching up edges with my high grit natural. I just keep it on the counter and run the knife over it a few times before I use it and it works really well. You could do the same with the glass 6K.

Re: Sharpening with diamond plates

Fri Nov 09, 2012 8:39 am

I only want to comment on the EEF DMT stone. I bought one several months ago. I got the duo stone (with holes) that was 4.25" long. I have had the other grits for a few years and they are completely broken in. I tried and tried to get the EEF stone broken it but never got to the point than an EEF stone should be. I could finish with the EF stone and have a very nice sharp edge with a very clean almost mirror bevel. When I used the EEF stone to polish the bevel some more all the EEF stone did was scratch it up worse than the EF stone left it. I contacted DMT and they replaced it. I had the same results with the second stone. So, IMO I'll never use any DMT product finer than EF. There aren't many stones that come in EEF anyway from DMT. You can definately get stones that will pick up where the EF DMT leaves off. The Shapton glass stones are the best I've ever used. However, they are the only ones I've used that fall into what I call the "better quality" category.

More info on the EEF stone. I used a flat edge slicer attempting to get the stone broken in. With a flat edge blade I could hit the entire stone. With a blade with a curve or belly only part of the blade is making contact with the stone. When breaking in any diamond stone I try to get the entire surface to be consistant.

I've never used them but most who have feel the Atoma diamond stones are better than DMT. That's pretty good IMO because I've been very happy with DMT products. I don't have near the experience that most of these guys have though.

Re: Sharpening with diamond plates

Fri Nov 09, 2012 8:20 pm

The EEF will become finer than a broke-in EF stone but it will take equal amount of use. It's not something that will happen in a few days or maybe even a few months. It all depends on how much it is used.

Re: Sharpening with diamond plates

Sat Nov 10, 2012 5:45 am

Jason B. wrote:The EEF will become finer than a broke-in EF stone but it will take equal amount of use. It's not something that will happen in a few days or maybe even a few months. It all depends on how much it is used.

I think I have spent 3 or 4 hours while watching TV stroking the stone with a 10" slicing knife with a straight (no belly) edge. I will work on it some more because I am curious and I would like for it to perform like it should and like I hoped it would.

It does make me wonder why someone would want to get a complete set of diamond stones. I have come to the opinion that I will use DMT stones for fast steel removal of course and also progress through the EF grit for outstanding results. I don't think anyone can argue the performance of the DMT products. But for the ultra-fine, mirror edges they don't seem to be the appropriate tools. We'll see how I feel after some more work on the EEF stone. Even if I do get it broken in to where I think it should be I'd have to say I'd rather buy a different type stone for very very fine grit sharpening. Or, I think DMT should do the breaking in themselves. If I do get the stone to be what I'd call EEF it will have required far too much effort and time to get it there. This is just my opinion of course. If the stone lasts for years giving the results it should I imagine I'd forget about the trouble it took to begin with. I'm not dissatisfied with DMT, just the EEF grit. DMT stones were what I used to first get my knives sharp enough to slice printer paper from the edge without any effort.

I would love to try some Atoma stones sometime. Can anyone enlighten me on how the finest grit Atoma stones do? Also, do they require the break-in period that DMT products do? I use an EP and have talked to the DMT people via phone and email several times about them making their duo-sharp stones for the EP. They are much lighter than the continuous surface dia-sharp stones. The last they told me was they were not going to persue 1x6" stones for the EP. I have used the 4.25" stones on the EP and while shorter they do a nice job. Sure would like the extra length though. There are Atoma 6" stones for the EP. I think they are the solid steel type which are heavy. I'm sure they work I just like lighter stones when using light strokes with the EP. Since the stones are on top of the blade I mean. For bench stones however I prefer the extra weight.


Re: Sharpening with diamond plates

Sat Nov 10, 2012 8:00 am

You waited for your EF stone to break-in without complaint so why wouldn't you wait for another DMT stone? Doesn't make much sense if you ask me.

If you bought a coarse DMT hone you would need to run the same course, though the opinion might be it looses its coarseness.

Bottom line, DMT stones need a break-in period and its not going to happen with one knife.

The EEF stone provides a very fine finish to the right steel (hard and wear resistant metals) but its not going to be a mirror edge, that's why DMT made diamond paste.
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