E-Z Lap vs. DMT -- Why Different Results?

[Ace Rimmer]

I'm hoping to get some help with understanding why I get different results between E-Z Lap and DMT diamonds despite using the same technique with the same-sized plates.
My sharpening needs are simple -- mostly Case SS and CV, a few Victorinox, and some Bucks ranging from 440C to 425M to 420HC. My main sharpening tools are four inch diamond plates. I have E-Z Lap 600 and 1200, and DMT 220, 325, 600, 1200, and 8000. I have a couple of four inch ceramic rods and Opinel and Victorinox mini steels for finishing touches as needed or desired.
So here's the problem: With the E-Z Laps I can easily get any of my knives suitable sharp, by which I mean they will easily pop a single arm hair off with the slightest touch. But with the DMTs I can't get the same results. I can get the knives "sharp," but not "really sharp." I'm using the same freehand technique with both, and I think the results with the E-Z Laps shows that my technique is "OK."
I typically touch up an edge with a 600, then refine a little bit with a 1200. I might do just a little honing with a ceramic rod (grit or grade unknown, but seems quite fine), and I find that a few strokes on a mini steel does a great job of eliminating any remaining burr. As I've indicated above, the E-Z Lap results meet my needs, but the DMT results are somewhat disappointing.
Any advice would be appreciated.

 

[Blues]

Monocrystalline vs Polycrystalline? Slight manufacturing variations. Not working the DMTs down enough beforehand? It's been discussed many times, I don't know if there is a definitive answer.

 

[catspa]

Here’s the surefire solution to your situation: use the EZ-Laps. Put the DMTs aside until you feel like experimenting with a different technique, steel or edge geometry, or sell them to somebody who’s been using a Harbor Freight diamond cube, or give them to somebody who did something heroic for you.

Parker

 

[Obsessed with Edges]

I see wide variations in how diamond hones work, between different brands. Each will be unique in how they respond to the individual touch applied. I sort of cut my sharpening teeth practicing with DMT hones until at some point, everything clicked when I figured out the right touch for those particular hones. I've got a double-sided folding hone from EZE-Lap in 400/1200 grit, and it's pretty good, a fast cutter of steel and very good for the initial shaping of new bevels. But I've always favored my DMTs for how they finish, with fewer burring issues than any other diamond hone I've tried. But again, a big part of that I think comes down to figuring out the 'touch' for them - DMTs respond beautifully to the lightest finishing touch I can manage.

Some of EZE-Lap's dealers describe them as having a blend of monocrystalline and polycrystalline diamond, with that combination designed to cut fast initially and then refine to a finer degree (grit-wise) with use, as the polycrystalline diamond fractures into smaller particles, which keeps exposing fresh, sharp cutting edges to keep cutting the steel efficiently, but at a somewhat smaller particle size and therefore a finer finish with some use over time. I've seen this behavior in the EZE-Lap I have. But the one thing I've consistently noticed with my DMTs is, they've always done a better job in the finishing stages, leaving an edge that requires little or no stropping afterward. And all of this has been with a very similar range of steels in the knives I use most, such as from Case and Buck (420HC in both brands, and Buck's older 440C blades) and also from Victorinox. I've also had very good results in knives with more wear resistance like S30V, S90V and D2, all of which benefit the same way in the finishing stages on the DMT hones.

 

[Ace Rimmer]

I see wide variations in how diamond hones work, between different brands. ....

Thanks very much for the detailed reply. I've learned to use a light touch, but it may be that I'm not using a light enough touch with the DMT. The two brands definitely have a different feel to them. I will experiment some more and see if my results change.
As far as the E-Z Lap surface changing with continued use, I have a couple of the round E-Z Lap diamond rods from many years ago and I remember their instructions talking about how, if you think the rod is "wearing out" then just run it across a glass ashtray (remember those?) and you will see it's still cutting. (Those rods were the first thing I found that would sharpen my 440C Buck 110!)

 

[Obsessed with Edges]

Thanks very much for the detailed reply. I've learned to use a light touch, but it may be that I'm not using a light enough touch with the DMT. The two brands definitely have a different feel to them. I will experiment some more and see if my results change.
As far as the E-Z Lap surface changing with continued use, I have a couple of the round E-Z Lap diamond rods from many years ago and I remember their instructions talking about how, if you think the rod is "wearing out" then just run it across a glass ashtray (remember those?) and you will see it's still cutting. (Those rods were the first thing I found that would sharpen my 440C Buck 110!)

One thing that helped me a lot when things finally 'clicked' in my use of my DMTs and all my other stones, is that I always do the finishing passes with the hone in one hand and the knife in the other. For me, it greatly helps when I can actually feel the pressure I'm exerting against the hone with the blade. With everything held in the hands, it allows a much quicker, intuitive adjustment in my use of pressure. And for the hand holding the knife, I pinch the handle just aft of the blade's ricasso between the pads of my thumb and forefinger, or even pinching the ricasso itself if there's enough there to hold onto. I maintain a light hold, but still firm enough to maintain control of the angle. That also enhances what I'm feeling via my fingertips and it's much easier to sense when pressure is too heavy or too light. AND, in doing all of this, I always prefer to keep the edge of the blade toward me, so I can always see if the apex is making flush contact on the hone. In order to always have the edge facing me, this means I switch the blade & hone between hands each time I flip to the other bevel. That took some time to train my hands for that, as I wasn't particularly ambidextrous before. But the hands and muscle memory can be trained for it, and it pays off. It did for me.

I do have one of the old EZE-Lap diamond rods, a model M, the one inside the brass housing that can be unscrewed, flipped around and used as the handle for the rod. I probably bought that one 35-40 years ago, maybe longer. It has been a good one for me, once I'd figured out the touch as I described above. For a very long time, I hadn't used it much, just because I hadn't yet figured that out.

 

[Ace Rimmer]

One thing that helped me a lot when things finally 'clicked' in my use of my DMTs and all my other stones, is that I always do the finishing passes with the hone in one hand and the knife in the other. For me, it greatly helps when I can actually feel the pressure I'm exerting against the hone with the blade. With everything held in the hands, it allows a much quicker, intuitive adjustment in my use of pressure. And for the hand holding the knife, I pinch the handle just aft of the blade's ricasso between the pads of my thumb and forefinger, or even pinching the ricasso itself if there's enough there to hold onto. I maintain a light hold, but still firm enough to maintain control of the angle. That also enhances what I'm feeling via my fingertips and it's much easier to sense when pressure is too heavy or too light. AND, in doing all of this, I always prefer to keep the edge of the blade toward me, so I can always see if the apex is making flush contact on the hone. In order to always have the edge facing me, this means I switch the blade & hone between hands each time I flip to the other bevel. That took some time, for me to train my hands for that, as I wasn't particularly ambidextrous before. But the hands and muscle memory can be trained for it, and it pays off. It did for me.

I do have one of the old EZE-Lap diamond rods, a model M, the one inside the brass housing that can be unscrewed, flipped around and used as the handle for the rod. I probably bought that one 35-40 years ago, maybe longer. It has been a good one for me, once I'd figured out the touch as I described above. For a very long time, I hadn't used it much, just because I hadn't yet figured that out.

Yes, I always use the two hand method. For me it seems to give more control and lets me keep the angle more consistent, keeping everything up near eye level where I can see what's going on. The Model M -- that's the one! I have two, one is as old as yours, and one that I bought for my father and then inherited back. Regarding the left-right switch... Doesn't sound easy but I'll have to try it.

 

[Ace Rimmer]

But again, a big part of that I think comes down to figuring out the 'touch' for them - DMTs respond beautifully to the lightest finishing touch I can manage.

Again, thanks. This weekend I sharpened two Buck 440C knives with the DMTs, my 110 two-dot and 112 two-dot. I was very pleased with the results. I made sure to use a very light touch. Perhaps with my Case knives I've just been using too heavy a touch. Next time one needs a touch-up I'll try the DMTs again and I suspect that I'll get the results I'm hoping for.