What is the role of a diamond stone??

Col Defender

Col Defender

Joined
Nov 11, 2011
Messages
1,398
Hi everyone

My sharpening skills and knowledge are modest for sure. I use a Spyderco Sharpmaker and also have a couple of Arkansas Oil Stones that I use. I just got a diamond stone but I am confused on when to use it and on what. (I got it for myself while buying one for another person without really knowing what I was doing.)

So is the diamond stone the final step after the Arkansas Oil Stones or is it for a specific type of knife steel, or just where does it fit into the sharpening process.

Don 't know what I'm doing here but it sure is pretty! :rolleyes:

Thanks in advance...
 
Without knowing the grit size of your diamond stone, or the type of diamond pattern used, let me suggest some possibilities. "Usually" diamond stones are more aggressive than other types, and will cut faster. They are more effective on the newer, harder steels than most other types of stones. They 'may' be too aggressive for some of the softer carbon steels. Generally speaking, folks use diamond stones as the first step in re-profiling an edge because they can remove a lot of metal quickly but leave deep scratch marks that will be polished out as one progresses through the finer grits of other stones. If you can tell us the grit size or mesh of your stone, and perhaps the maker, we can give you a more precise answer.


Stitchawl
 
+1

Good answer.

There are other things to know about diamond stones, but we need to know what stone you have, and what you're sharpening, and what you normally use the knife for, if you want a really good answer.
 
The diamond plate can be used for grinding, sharpening, and even finishing a blade. It's best used on hard and VERY wear resistant steels. It does not do so well with basic carbon steels or low alloy stainless in most cases.

They provide probably one of the most aggressive finished cutting edges of all sharpening media while providing a clean and pure edge that is free of burrs and debris. This results in a high degree of sharpness at nearly any grit with minimal effort.

I have the DMT diamond hones from 120-8000 mesh, its a complete sharpening set that allows me to finish a edge with a high polish or a coarser toothy edge depending on the use of the blade. You can continue on with diamond polishing compounds for extreme sharpness which can go as high as 400,000 mesh. Personally I like to stop around 1200 mesh and finish with a bare strop, gives a nice balance between sharpness and cutting ability.
 
Wow - already some great answers and helpful! My stone is a "Diamond Sharpening Stone, SKU#11217" from Hobby Tool Supply in Carlsbad California. Their ad says it is a combo fine and medium grit. (Two sided). Now that I know it is for the first step in re-profiling an edge I will be using it first on any really dull knife. I also have to learn about types of knife steel because I do not know the relative hardnesses of various steels. BTW is there a good primer for that subject or even just a chart of common knife steels ranking them from softest to hardest etc?

Obviously I have a lot to learn!

Thanks
 
Infer from SE (HF) diamond stone, your stone med=400, fine=600grit. This bothside of this stone are very aggressive when new, even after initial break-in.

Go to zknives.com to learn more about steels. Mostly steels consider to be hard to sharpen, are high % in Vanadium &| Tungsten (+ some other carbide former). Diamond also nice for abrading some 64+hrc blades (warn: n/a for high rc simple steels).
 
Hardness is a minor factor and usually depends on the maker. It's the wear resistance due to the alloy elements within the steel that cause the issue. Vanadium carbides for example are over 80 hrc and is what causes trouble for lesser sharpening stones.

Read again... Diamonds can be used for all stages of sharpening.... They just work best with modern metals.
 
Finally someone says it. The difference between 1095 at 56 rockwell hardness and 65 rockwell is not going to be significant with respect to the abrasive in any quality stone.

I am intersted in issues with simpler steels and diamond stones if anyone can provide details.
 
Diamond hones work fine on both high carbon and high alloy steels. I use diamond hones for 99% of my sharpening, and have yet to wear one out after more than a decade of regular use. For re-profiling I use the coarsest grit, but most of the time the medium (red) and fine (green) are all I need. I do strop using chromium oxide on the strop.
 
me2 said:
Finally someone says it. The difference between 1095 at 56 rockwell hardness and 65 rockwell is not going to be significant with respect to the abrasive in any quality stone.

I am intersted in issues with simpler steels and diamond stones if anyone can provide details.
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Regarding issues with simpler steels sharpened on diamond hones:

The biggest thing to watch out for, as I see it, is to pay VERY close attention to watching for burr formation. Simpler steels, like 1095 and some very basic stainless steels (such as with a Victorinox SAK), will abrade like warm butter on a diamond hone, and it's real easy to overlook the burr when it forms. It's possible to miss it, because the diamond can create it, and then scrub it away in just a pass or two. Many have complained about how their (simpler steel) blade never seems to form a burr on a diamond hone. But, odds are, it was there and they just didn't detect it. One way to minimize the risk of missing it, is to use a finer diamond grit on these steels. With these, I seldom use more than a medium or fine grit, especially when I know I'm close to the apex, and I need to start watching for the burr. And even then, keep pressure extremely light, and check the edge after almost every pass.

Another issue I've noticed with many 'softer' and more ductile stainless steels (such as 420/440 series), a coarse or XC diamond hone seems to clog very easily on them. I'm sure that's a testament to how fast metal is being removed initially on these. So, if you notice your C/XC diamond hones seem very 'slow' on these steels, it's likely the hone needs to be cleaned up, and will likely need re-cleaning multiple times during a sharpening session. Wetting the hone with water, water + dish detergent, or mineral oil might help a little bit in clearing the swarf. I used to use my Lansky diamond hones with water alone, but even then, I still noticed the coarser hones clogging up pretty quick. Part of that may have been due to the water evaporating rapidly from the hone. Something that stays 'wet' longer might work better.


David
 
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me2 said:
Finally someone says it. The difference between 1095 at 56 rockwell hardness and 65 rockwell is not going to be significant with respect to the abrasive in any quality stone.

I am intersted in issues with simpler steels and diamond stones if anyone can provide details.
Click to expand...

While some don't mind I feel the the edge left by diamond hones on simple steels is un-refined, deformed, and full of debris. The hardness and fact that the diamond abrasive is fixed in position tends to cause deeper gouging and heavy plastic flow of the metal which in turn causes excessive burring.

I believe in paring stone and steel as different steels will react to different types of abrasive resulting in a sharpening that goes smoothly or one that is troubled. With a basic steel like 1095 or 440c I will gladly use a waterstone over a diamond stone. Even in the world of waterstones different brands and stone construction affect the ability to sharpen different classes of steel. Now, if its S110v guess what type of stone I'm using?
 
I use DMT diamond stones exclusively for all of my sharpening. Most of my blades are good ol carbon steel.

I agree with all the comments regarding the diamond stone potentially leaving an unrefined edge on carbon steel, but I have gotten enough practice using the diamond stones on basic carbon steels that I can get a hair whittling edge that cuts very aggressively with pretty much any knife.

The trick is that you have to use VERY light pressure with the diamonds and it helps immensely to use a guided system. Using light pressure allows you to take full advantage of the aggressive cutting that diamonds give you without giving a severely deformed edge. Using a guided system means that your edge angle stays very consistent so you are not constantly creating and removing burrs due to varying angle. A guided system in my opinion allows you to use lighter pressure as well because you can focus on keeping constant light pressure without worrying about the angle.

On a knife that already has an edge established and just needs to be sharpened I typically use only 1 stone, the DMT Fine (Red) stone. I can work up a very small burr flipping it from side to side and then doing alternating strokes to reduce the burr. Then I use a homemade strop insert (http://www.bladeforums.com/forums/showthread.php/993761-DMT-Aligner-Strop-Insert) with some green compound to get rid of any large deformities on the edge. The result is a VERY aggressive cutting edge that will easily shave and will split hairs most of the time (the longer time I spend stropping, the more likely it will split hairs).

I'm so happy with my sharpening routine I don't see myself ever switching. I can reprofile an edge with ease using my DMT XCoarse stone and at the same time I can sharpen a dull blade to hair splitting in less than 15 mins. All while I watch TV because I use a guided system.
 
The problems I see with using diamond stones on simple steels are likely not noticed by most, I'm one picky SOB about a edge. It's not to say one can't work past these problems just that I paired a different/better stone to the steel and found the results less troublesome.

It has a bit to do with exposure too. If you don't have a multitude of different stones to try on different steels then where is the comparison?
 
That's very true, I don't have a good comparison. I do have a basic 1000/6000 Japanese whetstone, but admittedly my freehand skills are not on par with my skills using the aligner so I just have not used it much.

At the same time though, I just put a hair whittling, TP push cutting edge on a 52100 blade using my DMT aligner. I did have to go all they way to the DMT XXFine (Tan) hone and I spend a considerable amount of time stropping, but it certainly is possible. That said, I actually prefer the aggressive cutting edge that I get with the Fine diamond hones because it seems to make the working edge last a little longer on my carbon steel knives that tend to have less wear resistance than modern steels.

If only someone would come out with a set of waterstones that fit into the DMT aligner insert I'd be all over them. I've actually been toying around with the idea of securely wrapping some wet/dry sand paper around one of the DMT stones and experimenting with that. I bet if I could wrap it around tightly enough that would be a pretty good match for carbon steel.
 
My habits are very similar to Vic's (confucious37) above. I often set new bevels with a diamond hone & guided setup (Lansky or Aligner w/Dia-Folds; usually medium thru EF/EEF), then do the finishing touches on wet/dry sandpaper, finishing anywhere between 600 grit or higher. The roughness and/or debris issues mentioned, from the diamond hones, are therefore not an issue on finished edges. Both 1095 and 420HC, as well as other similar stainless, respond in stellar fashion to the sandpaper afterwards, as well as stropping on green compound (for the 1095, in particular) or 1 mic diamond paste on the stainless. This is also how I maintain these edges in the longer term (beyond stropping), using the sandpaper as needed.


David
 
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confucius37 said:
If only someone would come out with a set of waterstones that fit into the DMT aligner insert I'd be all over them. I've actually been toying around with the idea of securely wrapping some wet/dry sand paper around one of the DMT stones and experimenting with that. I bet if I could wrap it around tightly enough that would be a pretty good match for carbon steel.
Click to expand...

I've done both. You can have any stones you want cut to size at a local lapidary shop. (Check Yellow Pages) I've done this for years with stones for my EdgePro, and then later for the DMT. Pretty cheap and very accurate. And I wrap polishing films around my DMT Aligner stones to bring my finish up to 15,000 grit if wanted. The thickness of the film doesn't really cause any significant angle changes.


Stitchawl
 
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