Diamond Matrix vs. Shapton or Chosera for EP?

[Delphonic]

I’ve only used the stock EP stones and tapes. My recent addition of the polishing tapes has been impressed me though. Should have done it sooner. Thus, I’m wondering about switching stones. My impression is Edge Pro itself likes only the stones they sell, and that if Shapton or Chosera were better, Edge Pro would embrace them. That said, are their new Diamond Matrix stones about as good as it gets for an Edge Pro? Or is there still something (besides brand-name cachet) that warrants Shaptons or Choseras? Has anybody compared the Diamond Matrix to the other top contenders? How strong is the consensus that the ordinary stock EP stones are bested by the pricier choices? Many thanks!

[Radar53]

Hi there Del & welcome to the forum.

I'm a long time user of the EdgePro - first got my Apex in 1999 & wasn't really aware of third party alternative stones until I found this forum in 2014. Despite finding the forum I hung onto my standard set of stones for a long time and resisted the persuasive advice to "upgrade".

In hindsight that was a really BIG mistake. The difference in performance, especially for lower grits, on the newer, harder, more alloyed steels is chalk & cheese - night & day. I hung on to the EP stones waaaaaaaaay too long.

Much as I love the EP and think that it's still one of the best jigs options on the market, EdgePro themselves don't seem to embrace newer developments, accessories etc with any gusto.

Depending on what you're looking for, get yourself a set of third party stones Shapton Glass or Pro, Chosera, Nuabatama - all of them will be significantly better than the standard EP stones. You could even do a mix & match of different third party stones to explore the different feel, results, finishes etc.

Having said that the EP1000 & the EP1200 provide good finishes and work reasonably effectively & are good stones in their own right. In grit numbers they are equivalent to approx 3500 & 4500 grit Japanese stones. Their better performance is mainly down to the fact that by the time you get to grits this fine, all the heavy lifting has already been done and you are really only just polishing an already established edge.

Just be aware that there are a lot of different "grit number" & grit size" standards out there, so you need to understand what you are getting into. In my opinion the micron size is a far more useful number. You can see the differences on charts & tables here viewtopic.php?f=4&t=196

Hope this helps

[Delphonic]

Thanks, Grant! Very glad you shared your experience. Have you tried out the new diamond matrix stones? Given that the stone portion (as distinct from the aluminum backing) is about $10 each on most or all of the standard EPstones, I guess I don’t have too much trouble believing they can be surpassed. I’m not sure why EP wouldn’t embrace them, given the fanatics who constitute a great deal of their customer base. Ben Dale even criticized as ineffective one brand of fancy third party stones in a YouTube interview— people not able to get results with these primo 3rd party stones. But I would be curious to know if their premium offerings were on par with or better than Shapton or the other premium stones. Thanks again for you help!

[Radar53]

Hi Del, I'm not sure either about the "why". Ben designed, commercialised and patented the best jig the market had seen, which dominated that market until about 2010 when his patent expired. It was almost exactly the same in 2010 as when it first hit the market. Since 2010 a number of competitors have hit that space with some pretty interesting equivalents that are innovative and different. It's still a great piece of kit, but in today's fast moving markets, if you stand still you get overtaken.

I'm not sure that I understand what you mean by their "premium offerings". Certainly the scissor sharpener is unmatched and the small knife attachment is useful. The EdgePro itself can still hold it's own against most of the new competitors. The stones just don't cut it any more (pun intended!), but they are cheaper. The only reason the EP1000 & EP1200 are any good is that all the hard lifting should have already been done previously.

I can't comment on their diamond matrix stones as I haven't tried any of those. I'm not a fan of diamond stones for sharpening, because generally the scratch pattern is really aggressive and often needs to be finished with a standard stone of the same grit rating / size. Having said that, what I do with harder-to-sharpen knives and some difficult, wear resistant steels, is use 3M diamond films on some EP aluminium blanks. I have found that these cut like crazy and leave a very acceptable and consistent scratch pattern / finish. The result gives a bit more of a toothy edge than the equivalent grit stone.

Come back if you have more questions

[Delphonic]

Interesting on the 3M films. Ben told me their tapes are from Japan and slightly better than the 3M stuff, but then again he only sells three grits of tapes. Not sure whether to try the Diamond Matrix Stones or a few Shapton stones. Is there a consensus about which grits matter more to ultimate quality? The low grits do the bulk of the work, but the highest grit has final say in the matter.

[Otaku19]

If you are going to sharpen high carbide wear resistant steels, I would highly suggest using the Edge Pro Diamond Matrix stones or diamond stones in general. Shapton Glass stones are only going to cut wear resistant steels with less than 4% Vanadium, that is just how they were designed. I have quite a bit of experience sharpening high carbide, wear resistant steels in S90V, S110V, M390, 20CV and Elmax. I just got in a set of the Venev Bonded Diamond stones that are very similar to the Edge Pro Matrix stones but I haven't gotten to use them just yet. I'm hoping to be able to sharpen with them in the next week. Michael Christy did a fantastic video on these stones: https://www.youtube.com/watch?v=CpUP8lP6ilg

[Radar53]

Hey Anthony, nice to see that you are still trucking along - hope this finds you fit and well. I definitely agree with your comments relating to high and large carbide steels & I'll be interested to know how you get on with your new stones & what you think.

I know on this forum that there are different opinions on carbides & the "chocolate cookie" effect. I still have an open mind on this, but the engineer in me is evidence based, and despite asking three or four times on the forum, if someone with access to an scanning electron microscope could do some side-by-side tests to actually show what happens to a high carbide steel, using diamond stones vs say Shapton Glass, nothing as yet. But I'm still hopeful that one day ....

For now I am taking the conservative approach and using my diamond tapes on the these high carbide steels.

Del. Yep I think that Ben has taken a market testing approach & just gone for a coarse, medium & fine approach. Another forum member got me into the 3M tapes and was kind enough to send me some samples from 120 grit through to 150,000 grit (that is not a mis-print!!). I think that I might have used up to 10k so far & being impressed I subsequently ordered a selection of 120 through to 10k with a rough doubling of grit size.

All for now

[Otaku19]

I know on this forum that there are different opinions on carbides & the "chocolate cookie" effect. I still have an open mind on this, but the engineer in me is evidence based, and despite asking three or four times on the forum, if someone with access to an scanning electron microscope could do some side-by-side tests to actually show what happens to a high carbide steel, using diamond stones vs say Shapton Glass, nothing as yet. But I'm still hopeful that one day ....

For now I am taking the conservative approach and using my diamond tapes on the these high carbide steels.

I agree with your approach and I would like some more research on the microscopic level to confirm what is actually happening.
My theory is that the carbides aren't ripped from the matrix, just that the alumina based stones could actually be dulling the carbides versus ripping them out. Michael Christy has documented his research on using alumina based stones on S110V and that edge cut significantly less cardboard than a DMT and diamond stropped edge: https://www.youtube.com/watch?v=XmvtbYtQYSo

[Otaku19]

I know on this forum that there are different opinions on carbides & the "chocolate cookie" effect. I still have an open mind on this, but the engineer in me is evidence based, and despite asking three or four times on the forum, if someone with access to an scanning electron microscope could do some side-by-side tests to actually show what happens to a high carbide steel, using diamond stones vs say Shapton Glass, nothing as yet. But I'm still hopeful that one day ....

For now I am taking the conservative approach and using my diamond tapes on the these high carbide steels.

I agree with your approach and I would like some more research on the microscopic level to confirm what is actually happening.
My theory is that the carbides aren't ripped from the matrix, just that the alumina based stones could actually be dulling the carbides versus ripping them out. Michael Christy has documented his research on using alumina based stones on S110V and that edge cut significantly less cardboard than a DMT and diamond stropped edge. I'll try and find the video where he even used Nubatama stones on PM steel: https://www.youtube.com/watch?v=XmvtbYtQYSo

[Radar53]

Del. Medium vs fine vs ultra-fine finishes is another much debated topic among forumites, with very good sharpeners on either side of that fence. I really like finer finishes, but have been trying coarser finishing just to experiment. Typically I would have finished my Japanese knives with good steel at 5k to 10k, my good Euros (58HRC) at maybe 5 to 8k & for my rubbish Euros (54HRC) at 3k to 5k. Recently I've been changing that to 5k, 2 or 3k and 1k respectively and just checking it out. I've also played with different finishes on the same knife - eg RHS @ say 2k and LHS @ maybe 5k. Can't remember exactly now, but I think that Shibata-san does this on his knives with 800 one side and 1200 (maybe 1500) on the other and he's a heck of a sharpener. So play & have some fun.

Anthony. Interesting stuff from Michael, but he seems to mix media, which confuses things somewhat. To get an apples for apples comparison you'd have to get say three knives the same and sharpen #1 with just a diamond media progression, then #2 with just ceramics with exactly the same progression and #3 with alumina based stones again with the same progression.

But his test results might suggest that we are simply fretting about nothing in real world terms

[Otaku19]

I always finish most of my pocket knives on the 10k Suehiro but I have noticed that lower grit edges bite and cut abrasive media better in my opinion. I'm on the verge of using different finishes on my carbon steel gyutos since I have a few natural stones in my collection. I have a Rozsutec, Tsushima and a Yaginoshima Asagi. This is the video where Michael uses alumina based stones in a full progression: https://www.youtube.com/watch?v=WBoA8VI6koE&t=1073s

[Radar53]

Hey Anthony - this is really interesting. Michael obviously knows a lot more than I do regarding this and does a heck of a lot more real world testing than either I or many knife nuts do. The take-out for me is that, as the steels get more complex / alloyed, you need to use the appropriate abrasive to deal with that. If you don't then the edge is compromised to some degree or another.

His detailed findings seem to suggest that (a) carbide tear-out exists and (b) in steels with a high carbide content the grinding media needs to be harder than the carbides, to facilitate actual "cutting" of the carbide itself rather than getting tear-out. So I'll continue using my diamond tapes on these.

Thanks for the research & all the extra info.

Del - my apologies as we seem to have hi-jacked your thread. If you have any more questions or other ball to kick around, please don't hesitate to come back & ask those.

[Otaku19]

He did a great job doing the testing and eliminating the variables. Delphonic, I also apologize for taking this thread off topic

[Delphonic]

Hijacked or not, it’s interesting stuff to me!

[Delphonic]

What’s the best source of diamond tapes besides edge pro itself? 3M I know goes to .5 µm grit size whereas EP 6000k tape is 1 full micron, according to Ben Dale.

[Delphonic]

As for metallurgical considerations of sharpening, there is an Australian knife sharpening outfit that has a fascinating book that I caught a reference to on Amazon. There’s a white paper version of it detailing a sort of metaphorical construct of positive burrs and negative burrs. The guys who wrote seemed fairly rigorous. I can dig up the link if it’s of interest.

[Radar53]

I'd be interested in knowing more about the book. I've said it a few times on the forum, that I now wish I'd paid more attention during the metallurgy units I took at university.

The 3M tapes (which actually come in a 6" X 3" and 9" X 11" & maybe other sized sheets) go from as low as at least 60 grit to over 150,000 grit (say 60µ to 0.1µ). This is where I got mine from;

PRECISION SURFACES INTERNATIONAL, INC.
922 ASHLAND STREET HOUSTON, TEXAS 77008-6734 +1-713-426-2220 800-843-0950
FAX +1-713-426-2223
FAX 800-414-1644 www.psidragon.com info@psidragon.com
MICROABRASIVE CONSUMABLES
3M LAPPING FILM SHEETS
3M MICROFINISHING FILM SHEETS
3M POLISHING PAPER SHEETS
3M DIAMOND LAPPING FILM SHEETS
3M DIAMOND MICROFINISHING FILM SHEETS

[Delphonic]

http://knifegrinders.com.au/Manuals/Kni ... g_book.pdf

[Delphonic]

That’s a 24 page version of what I believe to be a larger book. It’s interesting material because of the rigor they brought to the inquiry. The biggest take away for me was that overt deburring is a bad idea. No felt blocks, etc.

[Delphonic]

The whole idea of a burr is a bit odd. It seems predicated on the idea that you never know you’ve gone far enough until you know you’ve gone TOO far. Not that I have any work around for this apparently necessary evil.