Diamond stone rant...

G

Gradyw

Joined
Jan 23, 2017
Messages
450
When I first started freehand sharpening I bought dmts.. coarse threw extra fine and used the uf spyderco to finish off... since then I have bought shapton glass and even some Japanese waterstones to try out which I think are awesome, all of them except the dmts. Sharpening on diamonds sounds cool.. they stay flat and aren't messy and before I bought them I read they were easier for beginners to learn on which may very well be true because I never could sharpen for shit until I bought the dmts and started practicing with those. Oh yea I have a couple atomas I use for lapping now too. Now That I have more experience though I can almost definitely say I hate sharpening with diamonds unless it's just for practice. One of the first things I realized were how much faster a 1k grit king stone was then a coarse dmt.. seems off to me? Has to be because I use light pressure on the diamonds because I'm scared to start ruining them.. with waterstones I'm not afraid to really lean into the knife when I am settting a new edge or fixing a small chip so they sharpen a lot faster. The second thing I noticed is how much rougher the diamond stones are compared to other benchstones.. I can't come close to a mirror or anything without scratches on my edge with my original setup even today when I'm almost positive my plates are broke in.. not really a big deal I guess because the cutting performance is still good but the last thing I noticed is I really don't like sharpening on diamonds anymore.. I think it's the feedback from them as I've seen a lot of people call it because it feels awful sharpening on those after waterstones or the shapton glass. On the coarser stones it almost feels like your sharpening over rocks and can feel bits jamming into your edge as you go sometimes.. I may be wrong and I honestly hope that I am because I spent my money on them haha. What is everyone else's thoughts on diamond stones that have used others? I've seen a lot of hate for them and never understood why until recently.. does anyone actually like sharpening on them for things that don't require they do like steel with car idea?
 
grit ratings are not the same for diamonds vs water stones etc.

otherwise I do understand what your saying. I kind of agree to a point. as for the mirror edge thing, it takes a lot of skill to get them without scratches in the end product.

I have venev diamond stones for my kme, they are bonded stones so much different feeling than the DMT stones. they also don't have the same grit ratings, they are much more fine and you can put more pressure on them if you wanted. they do sell them in larger bench stones but you have to special order them from Russia, maybe gritomatic can get them since they sell the stones for kme, edge pro and hapstone. but, as I said they are much finer and not course. I use my kme beast stone which is 100grit and it removes material fast in comparison to my DMT extra course bench stone (I think it's rated around 300grit?).

I like the diamonds regardless for super steel and d2. if im sharpening non super steel those water stones work quit nicely, especially for convex, scandi, scandivex etc.
 
The largest difference between diamond plates and bonded abrasives is that the grit protrusion of diamond stones is very high, which is why they're aggressive and "scratchy" for their grit rating compared to equally sized grit in a bonded stone. They're effectively really fancy sandpaper, if that makes sense. When comparing grit rating you have to make sure you're using the same rating method between stones, or else do a conversion on one of them to get a proper rating comparison.
 
I agree. Diamonds are slow if you use the required light pressure. If you wear the diamonds down, they're even slower.
 
I get the grit rating is different I can of just go by coarse medium and fine not so much the actual number. And yea mirror polish is a skill but I have a scandi knife I sharpened pretty hard on a 1k imanashi stone and still had a couple of scratches from the dmt that were really deep. They didn't come out but I didn't spend much more time on it but it sharpened up nice.
 
I use a sharpmaker and have diamond coarse rods for it. However the grit protrudes so much I have never been able to use them. The edge just seems to bounce off the apexes of the particles. Thus I can't sharpen with em for squat.
 
I use diamond plates for steels with high Vanadium content because they work more efficiently and do not have difficulties sharpening through the hard Vanadium carbides. Besides that, everything else gets sharpened on my waterstones because they do better with lower alloy content steels.

Even the Shapton Glass stones, waterstones known for not having much of any feedback, still have more feedback than diamond plates. This does not mean diamond plates are bad, they just feel different.

The King 1k being faster than a Coarse DMT is no surprise to me, the King stones get a bad rep for being slow though they are not as slow as made out to be. This also tells me you are sharpening low alloy steel as the comparison. Use a high alloy steel like S30V and you will notice a bigger difference.
 
Yea I realize that and it may have just been me sharpening with a new atoma 400 that made me hate it so much. I bought it for lapping but wanted to try it out.. besides the lower coarse diamonds which steel don't feel good the coarse stones just seem to scratch a knife up and I feel like I'm ruining the sharpener morethen anything.. I know they have a break in period (actually not sure about atomas I've heard mixed opinions on that) but I personally don't think I'll be buying anymore anytime soon.. I was hoping I was wrong though cause when I started out I loved them and didn't care much for any of the negative things I seen ppl write about them
 
I agree. I only use diamond stones (plates) for rough sharpening or re-profiling. For real sharpening I use natural stones or fine/very fine grit emory on a flat metal plate. Gets my blades as sharp as I would ever want anything to be (except my straight razor). I don't worry about my knives being shaving sharp. Who shaves with a knife?

Rich
 
send me your DMTs I personally love using them. I also am not a big fan of water stones. Yup just the opposite of you. In fact I sold all my water stones.
 
I'm not the world's most gifted sharpener, but I do a pretty decent job. I find diamond plates to be one of the easiest types to use for me. The only problem for me is that I tend to press down too hard. So my DMT C has some smooth spots on it where I scraped the diamonds off of the substrate.

I find the feedback to be excellent. I can really feel the edge on the diamonds and can deburr pretty close to 100% using just the diamonds themselves. I get *excellent* edges straight from the DMT stones

Now polish is a whole other thing. The reason that diamond stones seem to make more scratched looking edges, or are more rough than their grit rating would indicate is fairly simple: Not all abrasives are the same. Particle size is quite important, but particle composition is equally important. Diamonds have a very pointy shaped geometry. So these very sharp particles tend to dig in to the metal more deeply than other abrasives that are more flat or rounded. Diamonds are also incredibly hard and tend to not really "wear down" during use. Other abrasives do some combination of loading or smoothing out as you use them. Better abrasives like vitreous stones or waterstones will have the abrasive particles fracture off during use. Anyway, I'm getting a bit off track.

If you don't like diamonds, that's totally cool. Just know that some people like them and are able to get good results with them. I'd say the advanced sharpeners here can probably all get fantastic edges with them.

Brian.
 
Yea um they pissed me off the other day.. was expecting a good feeling stone from the atoma 400 but I guess since it was new it felt awful.. that and I'm scared to ruin it made me never want to sharpen on it again(I did get it for lapping so no big deal) the waterstones I have been using lately just have such better feedback the diamonds felt awful when I used them and had some problems getting a shaving edge off the atoma 400...with that being said I have tried it again since I used it to lap and it is mich smoother but still has nothing on waterstones.. I can get a fantastic edge myself. Off of them whether I'm using just the dmt c or going all the way to extra fine.. I'm sure the atoma will get better but I'm not to worried about it now. Just wanted to know everyone's opinion on them I wasn't trying to offend you guys who use them and like them
 
I mean it really felt impossible to sharpen on a new coarse diamond stone.. any of them.. maybe it's just me and I know they have a break in period but they feel rough on the edge and easy to rip out. I don't think anyone can argue with that.. can they? Lol
 
I only use diamond plates for lapping water stones and for setting or flattening bevels since I know the stones won't dish. I find going to an atoma 400 then down to a 220 water stone gets rid of the scratches from the diamonds and allows me to spend much less time on every other stone. I can usually skip some coarse grits depending on the size of the bevel.
 
I use them on high Vanadium steels and even stuff with larger carbides like D2 seem to benefit from diamonds. Otherwise I use something else.
 
I do the same as many others have said. Almost necessary for very high alloy super steels...M4, S60, S90, etc. but I never finish with them. Few odd comments. One about "shaving sharp" being overkill. To me, a knife that isn't Shaving Sharp, ISN'T SHARP! Another comment of diamond particles having more "pointy" geometry than other materials. In fact all abrasive particles are "pointy" to begin. The "rounding" of particles becomes apparent through wear. Wearing is of course, dependent on the hardness of said material, and material performing the wearing action.
 
Lapedog said:
I use a sharpmaker and have diamond coarse rods for it. However the grit protrudes so much I have never been able to use them. The edge just seems to bounce off the apexes of the particles. Thus I can't sharpen with em for squat.
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Keep working with them I have them an occasionally use them to reprofile a long sharpened knife. They are good for removing steel IMHO I edc a Gayle Bradley with M4 blade and they work great when I have ignored it and it needs a really good sharpening.
 
DavidHoback said:
Another comment of diamond particles having more "pointy" geometry than other materials. In fact all abrasive particles are "pointy" to begin. The "rounding" of particles becomes apparent through wear. Wearing is of course, dependent on the hardness of said material, and material performing the wearing action.
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Shape of the specific particles actually does have a very big impact on sharpening performance. For instance, aluminum oxide particles--at their sharpest--are more rounded than those of silicon carbide, which are much more aggressive in form. Even within the same abrasive type there can be different formations that give different results. Poly- vs. mono-crystalline diamond, for instance, are markedly different, and not just because of the increased friability of poly.
 
FortyTwoBlades said:
Shape of the specific particles actually does have a very big impact on sharpening performance. For instance, aluminum oxide particles--at their sharpest--are more rounded than those of silicon carbide, which are much more aggressive in form. Even within the same abrasive type there can be different formations that give different results. Poly- vs. mono-crystalline diamond, for instance, are markedly different, and not just because of the increased friability of poly.
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Mono & polycrystalline diamond abrasive's difference is not simply about the "shape". There is a "wife's tale" floating around that mono is better because it's a single crystal imbedded to the surface, where as poly have multiple, which make there holding power weaker, yadda, yadda! It's HYPE! There are actually different schools off thought on what characteristics the differences have, ARE! You can read several different from studies scientist much smarter than us, and have two entirely different schools of thought. You know what that means? No one truly knows EXACTLY! There is a bit of theory wrapped up with the truth...or TRUTHS, so to speak. The only thing for certain, is that abrasives with monocrystalline diamond particles cut much better than their polycrystalline counterparts. But it having anything to do with one being more "pointy" is a much too simplistic way of saying it. Although it can also get too difficult as well I guess. One could start the argument of which one is "self sharpening" because of fracturing, and if the fracturing is at, and because of the the cleavage planes or if fracturing occurs conchoidally! And then my dad can beat up your dad, but your mom can beat up my dad!!! And it goes on and on......
 
db said:
send me your DMTs I personally love using them. I also am not a big fan of water stones. Yup just the opposite of you. In fact I sold all my water stones.
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Same here except for in the field light touch ups... Big issue is stones lose their flatness when heavily used, this being particularly true of even the best coarse ones after some years: Some coarse stones lose their shape very rapidly. They need sanding down to a new flat. Diamond hones go smoother quite fast, but "level out" to a somewhat useable coarseness, and they absolutely never go out of flat... Most stainless steels almost require Diamond hones for great results, while diamonds are almost too aggressive for Carbon steels who get eaten so rapidly it is almost like the steel is "disassembled" by them...


Gaston
 
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