Edge Pro and diamonds (durability) question

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wvdavidr

Joined
Mar 21, 2007
Messages
370
Hello all,
I have been using the Edge Pro Apex for about 12-15 yrs., so I am no novice. I haven't tried diamond "stones" with it. I asked Ben Dale in an email about Atoma's and others. He said (also in a video) that diamonds are not compatible with steel... he has tried every diamond plate in the business and none lasted over an hour. In my freehanding attempts, I did feel like the diamond plates (DMT) lost most of their 'bite' pretty quickly.

My question: Have any of you used diamond 'stones' extensively on the Edge Pro and did they last?

Good sharpening,
Dave
 
My experience with diamond dust co-deposited with Nickel onto a steel substrate in an agitated electroplating bath has not been good. If you use too much pressure, you pull the diamonds out of the Nickel. If you use a pressure consistent with diamond conservation, it takes forever to sharpen a knife.
I am much happier with Silicon Carbide and Aluminum Oxide abrasives. They are much faster in my experience.
 
I gotta say the guy is full of it. Diamond plates last forever if you treat them right. You gotta use very light pressure, and need to clean the stones somewhat often. The advantages are the ability to abrade vanadium carbides which makes steels that rely on the vanadium carbide even better.

Now because of the super hard backing, diamond stones are more aggressive than normal stones, and can leave a seemingly more coarse,edge finer grits.

If you hear anything about the diamond plates not lasting, my XC has lived through dozens of sharpening and reprofiling sessions and is just as aggressive as the second or third knife I did with it.
 
wvdavidr said:
... he has tried every diamond plate in the business and none lasted over an hour.
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If that were the case, there would be a whole lot of Wicked Edge users having to replace their stones every hour!

Also, see what KME say about their diamond stones:

We’ve been experimenting and torture testing these hones for several months now. We’ve pushed them way beyond the limits of normal use. In fact we’ve been intentionally trying to destroy them. To date we’ve been unable to ruin even one hone. In the coarser grits there is some loss of diamond but we have not been able to remove enough diamond to see any noticeable loss of performance... even after days of abuse on the hardest “Super-steels”.
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Diamond is only incompatible (or at least not recommended) with steel when using it on powered grinding media. The high heat generated during powered grinding will catalzye a reaction between the carbon in diamond and the iron in steel, and is detrimental to the diamond. Diamond loses it's hardness at high heat, something up around ~800°C, if I recall correctly. This is why CBN is usually recommended as an alternative to diamond for powered grinding, as it remains much more stable at high temp, and doesn't react with the steel at all.

Otherwise, grinding steel on diamond plates by hand (and at normal environmental temperatures) is of no hazard or detriment to the diamond, the nickel plate or the blade. Literally decades of hard-used diamond hones out there to prove this. I'm surprised, or even shocked, if Ben Dale is actually saying (and believing) that diamond hones can't be durable when used for sharpening knives. If he's seeing some severe degradation in doing so, either he's using WAY TOO MUCH PRESSURE, or there are some severe manufacturing defects in the hones he's working with.

The ONE thing I've noticed in using diamond hones on guided setups is, the small size of the hone greatly limits the working speed of it, especially on larger and thicker blades. There's always a great temptation to push harder because of this (I've done it, with the tiny diamond hones on the Lansky set), and that extra 'grunt' against the hone is what can potentially kill it. Heavy steel-removal tasks can also clog a small hone very fast, so they slow down tremendously and lose effectiveness. The small hone size is (I believe) the greatest drawback of any of the rod-guided systems, especially since they're so often used for hogging off lots of uber-hard steel in the quest of re-bevelling blades. That's an awful lot to ask of any small hone, in work normally best done on larger bench hones or powered grinding systems.


David
 
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My two DMT 4X10" double sided diamond hones sit in the drawer while I grind Vanadium and Niobium carbide containing steels with impunity on my Silicon carbide and Aluminum oxide stones. Life isn't long enough to sharpen on diamond "stones".
 
tiguy7 said:
My two DMT 4X10" double sided diamond hones sit in the drawer while I grind Vanadium and Niobium carbide containing steels with impunity on my Silicon carbide and Aluminum oxide stones. Life isn't long enough to sharpen on diamond "stones".
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That sounds like use too much pressure. Realistically any pressure more than enough to control the blade can pull diamonds out. The stones stay out super coarse, but the very high points get sheared off or fractured down, and the stone evens out after a little use to its real grit.

The thing with diamond stones is that they abrade the actual carbides, instead of the matrix around them, leaving the carbides better off (and less likely to fracture out). Diamond and CBN can abrade all carbides (afaik), while SiC and AlOx can only abrade chromium carbides.
 
Atoma plates are the best I've seen so far. I've used a 140 plate for the Edgr Pro to reprofile dozens of high wear resistance steels. The Atoma 140 makes short work of S90V.
 
I think that there is frequently confusion as to whether diamond hones are wearing out or wearing in. Diamond abrasive grit is not applied to a hone with a perfectly level top service or with perfectly uniform grains. There are always some high spots where the apex of some crystal projects well above the average height of the grit. A new hone always feels aggressive as these high riding crystals gouge into the surface. The new hone does cut a bit faster than it will later, but at a significant cost in edge smoothness. The high-riding grit are subjected to much higher stresses and typically fracture and become low-lying grit. The surface smooths out. This is normal wear-in, not wear-out. The feel is different, but the edge is improved.

The big advantage with diamonds is that they have sharp edges and cut well into hard carbides. If you are satisfied knocking out large carbides any old abrasive will do. If you want to shape the larger carbides you need fine diamonds or something like fine boron carbide.
 
wvdavidr said:
I asked Ben Dale in an email about Atoma's and others. He said (also in a video) that diamonds are not compatible with steel... he has tried every diamond plate in the business and none lasted over an hour
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He must have a hidden agenda of some sort, I can't imagine anyone actually believing something that at his word. I have some diamond plates that are several years old that have gotten used for everything from flattening water stones to minor blade grinding. They still work just fine! The quote above about the KME stones is interesting, and you should also check out some of the wicked edge forums. I remember reading somewhere about the life of the stones (and they are pretty small) being several hundred sharpenings.

To directly answer your question: I don't have any experience with edge pro stones, but in my fairly lengthy use of diamond plates they are very durable and have an excellent lifespan.
 
Thanks for posting the video, I was looking for it but couldn't find it! That sounds, for lack of a better term, like complete hogwash. That irritates me actually, just sell your product on its own merits. Making broad claims of bad against other products that you can't back up just makes you look foolish.
 
I also watched the video, in full. The video has an obvious 'sell the product' bent to it, and I don't ordinarily fault that in itself, so long as it's not done at the expense of time-tested facts. But, I really wish I knew what the specific circumstances were, in forming his impressions of diamond hones. I have heard some of what he mentioned, such as so-called 'soft' steels wrapping around the diamond particles and dislodging them, but have never seen much merit in that claim. There's always some loosely-bound grit on new hones of any kind, diamond or otherwise, and therefore some of it will be scrubbed off occasionally. But I've yet to see a diamond hone stripped completely of it's grit. I've really, really tried to kill a couple of mine, in re-bevelling an S30V blade with a tiny 4" x 1/2" medium-grit Lansky hone, and in lapping two of my Lansky ceramic hones on a C/F Dia-Fold. All showed some additional wear, but still manage to eat steel like it's a light snack. Also lapped both sides of a Spyderco DoubleStuff hone on an 8" Duo-Sharp (C/F) hone, in about 3-4 hours' worth of grinding; it didn't show any visible wear at all, and even seems to have benefited from the 'break in' afforded by that job, as the hone's finished grind patterns really evened up after doing so.


David
 
I've been using diamond plates for years; At first EZE-LAP, then DMT. For about the decade of the 1980s I sharpened knives for all the guys in my hunting and fishing club. At the beginning of the season, when I had a high volume of knives to deal with, I often pressed hard on the coarse plates to re-profile edges in preparation for work with finer diamond grits.

I no longer belong to that club but the plates are still with me and working fine.
 
We only stock them for ceramic knives. I have tested every diamond on the market and not one of them lasted much over a couple of hours and most of them much less. So in total frustration I was telling a engineer friend of my dilemma and he suggested I call a tool company that specializes in diamond tools for industry, to get the straight story. So I did. I asked them if they would build me a tool to use on 58 Rockwell high carbon stainless. They said NO. They said that diamonds should never be used on steel and if they built me the tool, it would not last 10 minutes. Here is what happens. The diamonds sink into the steel, the steel surrounds the diamonds and pulls them off the plates. However if you are using a diamond on ceramic or carbide, the material is way to hard for the diamonds to sink in so they ride along on the points undisturbed. Now I know everyone sells diamonds for knife sharpening and here is why I think they get away with it and I can't. You buy a Gatco or Lansky Diamond, you get it out a few times a year and sharpen a few knives. The diamonds last a few years and you order a new set, thinking that was just fine. I sell a lot of Edge-Pro's to customers going into the sharpening business. These people are sharpening over 100 knives a day. Under these conditions a diamond won't make it to lunch.
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Den Dale



Ben has always had requests for diamond plates and he has always been adamant about not using them. He claims to have tried them and they suffer premature wear. You have to realize first that Ben sharpens a lot of knives and his sharpeners are made to sharpen a lot of knives, he isn't talking about the occasional user who sharpens a knife once a week, his machines are built to sharpen many knives a day. He argues that used side by side with other stones that diamond plates will wear out much faster.

Now before you jump in with a claim of having used a diamond plate for a long time realize that his plates are very narrow and thus the pressures on them are going to be much higher. This is compounded with the force being higher because the stone is inverted and it is being pressed into the knife and it is very easy to even with moderate effort put a lot of force on the stone. This is a really significant factor and why the Edge Pro could easily be putting 10X as much pressure on a plate as free hand on a regular benchstone.

Now what he is referring to in the industry is that diamonds will wear by carbon diffusion (diamond is just carbon) and thus diamond is not used to grind steel because of this as the wear rate is very rapid even though diamonds are hard. However you have to realize that they are talking about power grinding at high speed and thus heat and that this increases the rate of wear. The studies on this are not directly able to thus infer the same rate of wear at slow grinding speeds in hand honing with much lower loads and usually with a coolant/lubricant.
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Cliff Stamp
 
//QUOTE FROM POST #15// -snip-
you have to realize that they are talking about power grinding at high speed and thus heat and that this increases the rate of wear. The studies on this are not directly able to thus infer the same rate of wear at slow grinding speeds in hand honing with much lower loads and usually with a coolant/lubricant. //UNQUOTE//
It seems clear that hand honing with very little heat, using water as a lubricant, does not degrade diamond plates anything near high powered industrial processes. When it comes to durability and wear of diamond plates, hand sharpening and machine sharpening appear to be in different leagues.
 
For the most part there is some excellent information in this thread.

I don't really know what Ben Dales angle is here , but he is making some outrageous claims about diamond plates (in general) with zero documented evidence to back up such outrageous claims.

On a more durable Diamond Plate such as the Atoma 140 or DMT XXC you can bear down with some heavy pressure to speed up the process with no detriment to the steel or the plate.

I have had diamonds ripped out of a plate before (entirely not just a few) this happens when you use a diamond plate to lap a stone coarser than itself , in my case this was a 1k Pro with a 1200 Atoma. Just a few passes under running water destroyed plate. ( I was experimenting with texturizing). I have also had this happen on a 0.5u Diamond film , using it to texturize a relatively unique stone.

The fact is that in a hand application using diamonds to sharpen steel is not only more efficient when we talk about super steels with high hardness and abrasion resistant properties , but on something like an edge pro , they stay flat and if you use all the same brand of plates you never have to adjust for stone height.
 
I did not even know who Dale was until I watched the video and then looked it up. Since he is so adamant that his stones are better, I would love some feedback about their lifespan from someone who owns an edge pro.
 
Cynic2701 said:
Atoma plates are the best I've seen so far. I've used a 140 plate for the Edgr Pro to reprofile dozens of high wear resistance steels. The Atoma 140 makes short work of S90V.
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Could you (or someone else with experience) elaborate on how Atoma plates differ from say, DMT or EZE-LAP?
 
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