Have you see this before

[Joel Casto]

Not sure if this post is in the correct category.

Pictures below are my 3 Micron diamond stone set I got two weeks ago. After sharpening a few knives I noticed the diamond abrasive started wearing off, down to the base metal. It’s most noticeable on the extreme end of one stone, but it’s also in the center of both stones. It seems improbable to me that the diamond abrasive is wearing at all, but especially so after a few knives and only a couple weeks. I started to notice metal-to-metal contact when I use the stones and so stopped using them.

I sent pictures to WE tech support earlier this afternoon and should hear something next week. I’m new to the WE system and thought I’d ask for thoughts from some of the more experienced folks on the forum.

My first thought was “Hey, chucklehead, you’re doing something wrong”. But all my other stones, diamond, ceramic, lapping film and strops are just fine. Any ideas?

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[tcmeyer]

I’ve worn through one of my diamond stones by over-working it on a ceramic knife near the end of three years, but my wear pattern is quite different. On mine, the diamonds are worn off along the edges of the middle two thirds of the platen.

Which leads me to believe that maybe you’ve just got a bad pair. Something went wrong during the plating process. No worry, WE will make it right post haste. I just hope they don’t have a big batch of these out there.

I can’t even imagine why you’d see that wear at the end of the platen, as normal use doesn’t touch the ends. Did you maybe use it to lap another stone?

An ugly thought just entered my head… Don’t EVER rub the faces of two diamond stones together! Guaranteed damage!

[Joel Casto]

Thanks for the response.

No ceramic knives and I don’t rub any stones together (except strops) – not sure why anyone would want or need to lap the stones. And believe me, my first thought was “operator error” but none of my other stones/strops show this effect. I’d think I’d see it on the more fragile lapping films and strops if it were technique. They are all just fine

I thought about the plating process, too, although I don’t pretend to understand much about that.

[blacksheep25]

1) can you provide more details on the knives that were sharpened, including whether it was a re-profile (granted that the 3 microns would be used at the end)?

2) are you sharpening into or away from the edge? i’ve noticed with the 1200/1600 ceramics, if i cut into the edge, it will shave off stone material. so i always use those away from the edge. on coarser grit diamond stones I sometimes cut toward the edge.

i’ve have a metric ton of DMT diamond stones, and have not had a problem like the one shown here, but that doesn’t rule out a bad batch.

[Joel Casto]

Thanks. The 3 Microns followed a 100, 200, 400, 800, 1000, 1200, 1600 progression on Wusthof kitchen knives and a couple Kershaws. All knives were factory angles, re-profiled to between 18-25 dps.

I sometimes use a toward-the-edge technique with larger grit stones until a consistent profile is established and then away-from-edge until I get a burr. After 1000 grit I sharpen away from the edge with everything, the same as a stropping motion. As you note, the ceramics and especially the lapping films and strops won’t tolerate a toward-the-edge technique. As I mentioned in a comment above, I don’t see this with any other stone that I own, including lapping films or strops. I have several older DMT stones (not WE) and the diamond coating wears smoother but does not come off.

[blacksheep25]

If you look at the picture on the sales page, there appear to be markings for:

3 Micron
wickededge precision knife sharpeners
By
DMT

and the wear area(s) seem to roughly correlate to the location of the markings. if I had to guess, the marking process caused the diamonds in that area to not adhere well.

I don’t recall ever seeing any DMT products marked this way (on the diamond surface).

5string, can you post another pic of the entire stone; and maybe see if you can adjust the camera angle to see if you can see both the logo and the wear areas on the same pic?

[Joel Casto]

Sure, here are the stones with the DMT laser engraving. The wear points appear as shiny on the left stone and dark on the right. It’s hard to get the lighting right. The wear area is in the area of the engraving, except on the end of one stone.

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[Josh]

This is very interesting. About 6 months ago I ordered a DMT course/fine duo-sharp stone (roughly 320 and 600 grit) to lap my choseras on. I also used it a few times on some kitchen knives, just to see how my free handing skills were coming along. within about 2-3 knives I noticed the exact same “balding” along the entire length of the edges of the duo-sharp stone, appearing as if the diamonds just ripped out and left the plating. I think this is a flaw in QC on DMT’s part.

[blacksheep25]

This is very interesting. About 6 months ago I ordered a DMT course/fine duo-sharp stone (roughly 320 and 600 grit) to lap my choseras on. I also used it a few times on some kitchen knives, just to see how my free handing skills were coming along. within about 2-3 knives I noticed the exact same “balding” along the entire length of the edges of the duo-sharp stone, appearing as if the diamonds just ripped out and left the plating. I think this is a flaw in QC on DMT’s part.

Do you have pics of this; would be educational to compare it to the pics of the 3 micron stones from the OP.

[Joel Casto]

Update. Talked to WE this AM. Replacement 3 micron diamond stones are on their way. WE has the best customer service I’ve ever seen! Pleasant, caring, responsive. Thank you Sarah!

This gave me a reason to dive deep – so I ordered Choseras. I still haven’t “decoded” the process of moving through the grit order. And the different mediums, diamonds, ceramics, lapping film, strops, add to the complexity. The microfine ceramics leave a different scratch pattern than lapping film of similar or larger micron. And as some of the more experienced posters note, sometimes you go back down to go back up. It’s not a linear process. My guess is a lot of the more experienced folks have learned most of this or intuitively “get it”. But not me, and I’d like to see more discussion about the order folks use and the reasons why.

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