How to break-in a DMT extra extra fine plate?

[JPO]

I just ordered a DMT Extra Extra fine as a experimental plate for razors.
I already have a smaller plate. However, the biggest issue I see with this plate is oversized diamonds that create issues.
How can you knock down any high spots to create a consistent cutting surface?
My experience with my existing plate is that lapping other hard ceramic stones does not work to wear down the high spots. The abrasive just destroy the nikkel plating and you loose the diamonds.
For coarser plates lapping ceramic stones works fine as a break-in method.

 

[buca3152]

Sharpen some knives with it is what I would do. It does lose its aggressive nature quickly. I have one so what I'm telling you is first hand.

 

[Legion]

Lap a vintage Washita? That should bash it into shape without being horribly destructive.

 

[Empire straights]

Lap a vintage Washita? That should bash it into shape without being horribly destructive.

I was going to say a hard ark but I bet any novaculite would do it.

 

[JPO]

I have a soft/hard combination stone. I will give this a try. The hard might be less likely to abrade the nickel holding the diamonds.
I can also try the soft Ark under running water to limit the affects from the loose silica.

 

[captaincaed]

I'm curious as well, having read the @SliceOfLife threads on hone comparisons recently. Seems like a divisive stone, but maybe it can be tamed if used judiciously?

Along the lines others mentioned, the Spyderco F hones are incredibly hard, and slower to lap than even a hard Ark. They are also quite fine, and might be a good option since they're man made and not as rare or expensive as decent novaculite.

 

[sd_baker]

Scienceofsharp has a 2 part series, "Diamond Plate break-in". I think they introduce grit contamination and setup the groundwork for the surprising discovery that courser DMT plates actually produce a more uniform finer finish. On break-in:

In this example, the hone was “broken-in” by rubbing on a hardened steel surface for approximately ten minutes and then used to lap a Shapton 16k hone for a few minutes. The results are consistent with those observed in the case of the Fine hone. The diamonds that sit higher are removed or broken off, evening out the variation in the height of the exposed diamonds and smoothing the diamonds that contact the surface being honed.

 

[JPO]

I'm curious as well, having read the @SliceOfLife threads on hone comparisons recently. Seems like a divisive stone, but maybe it can be tamed if used judiciously?

Along the lines others mentioned, the Spyderco F hones are incredibly hard, and slower to lap than even a hard Ark. They are also quite fine, and might be a good option since they're man made and not as rare or expensive as decent novaculite.

I have now sacrificed some gold dollar steel, and done some more breake-in work of my smal 8k DMT.
Now I see less random deeper striations.
I also shaved with a razor that was honed on the dmt 8k, and finished with a 10k shapton stone.
The result was really good.

When I receive my new plate I probably have some work to do before the plate can be used with razors.

The fact that these plates starts to cut shallow as the edge gets thin behind the apex can open the door for them to be used with razors.
It is however really pressure sensitive. You are can also get into edge fatigue issues if you stay too long on the plate.

 

[captaincaed]

Gotcha. Seems like the extreme hardness causes the edge to flex away from the hone a bit, causing the user to hone a bit behind the Apex, thus thinning the bevel, potentially too much?

I also realized the obvious answer. Flatten it with another diamond plate. Jon Broida warned me against flattening a vitrified diamond stone with a diamond lapping plate because it blunts the diamonds instead of abrading the binder to reveal fresh diamonds. Because of that it doesn't leave the stone with an aggressive surface (which you normally want for knives, so SiC powder helps flatten vitrified stones). In your case, that's a feature not a bug.

 

[JPO]

Scienceofsharp has a 2 part series, "Diamond Plate break-in". I think they introduce grit contamination and setup the groundwork for the surprising discovery that courser DMT plates actually produce a more uniform finer finish. On break-in:

I actually think there is more potential then what he has been able to show in his tests.
I am not able to produce the same issues he is showing.
You only need one large diamond to ruin the edge. It's also pressure sensitive and the results are dependent on individual honing techniques.

 

[sd_baker]

I actually think there is more potential then what he has been able to show in his tests.
I am not able to produce the same issues he is showing.

Yes I understand the context of your experiments and am interested in seeing your results. I do not take everything Todd says as gospel. Case in point, he asserts that diamond grits below 0.25 micron do not improve keenness, which I personally found to be wrong.

You only need one large diamond to ruin the edge. It's also pressure sensitive and the results are dependent on individual honing techniques.

The pressure sensitivity is an interesting point. If you have a sea of large diamonds, i.e. a course plate, then the pressure is well distributed. However, if you have a few proud course diamond amongst a sea of finer diamonds, the pressure would be immense due to the small contact surface area.

 

[SliceOfLife]

Spyderco UF's are stones I wanna love. @global_dev sent me a UF finished razor (or razors) that was/were really quite good and made me break mine out again a few years back... and they're capable stones... but I just can't get myself to like them as well as a hard ark.

Was posting something about them being an option due to price... and went to confirm price before I did... It's gone way up.

I remember (maybe misremember?) the 8x2" going for like $50 or 60... Looks like it's almost $150 now.

Personally; I'd rather put that money towards an Ark.


I can summarize the UF in this way. It's a stone when I use it, I go: "Yeah that's a perfectly fine hone/shave", then I put it away and it sits on my shelf for five years without even being looked at. Definitely a stone a guy who takes the time to get good with could shock some people with the results of though.

 

[captaincaed]

Spyderco UF's are stones I wanna love.

Hear hear.

I bought both F and UF to satisfy my curiosity, and I'm reasonably satisfied that they are the same material, with different surface prep. The good part is the F stones are $75 on Amazon, if you're willing to put in a few minutes with some sandpaper.

That said neither came even close to flat out of the box. Flattening was awful.

I lapped the F to a polish similar to the UF, but without the swirls that I felt might ding up a fine razor edge. I'm playing with it off and on. Maybe I can tease an Ark-like edge out of it.

 

[LJS]

I had to work on my spyderco before it was suitable but no way I would drop $150 for one. I have an older version DMT 8K and always felt I got a dud I think they missed the abrasive step but is a great flat plate instead for other things. It came in an unappealing way like it was dropped in a bin with others off a conveyor line. Always wanted the DMTs to work for me and cut out the stones requiring flattening. But my green 1K shrimp brick is still key bevel setter in my razor work.

 

[SliceOfLife]

Hear hear.

I bought both F and UF to satisfy my curiosity, and I'm reasonably satisfied that they are the same material, with different surface prep. The good part is the F stones are $75 on Amazon, if you're willing to put in a few minutes with some sandpaper.

That said neither came even close to flat out of the box. Flattening was awful.

I lapped the F to a polish similar to the UF, but without the swirls that I felt might ding up a fine razor edge. I'm playing with it off and on. Maybe I can tease an Ark-like edge out of it.

I believe Spyderco actually confirmed that in the past. They are the same.

I think I owned two in the past, F polished, Sold, few years passed, I bought a UF, polished it too (less work I guess?). Sold.

Then I got a F used & prelapped for cheap off eBay and it's kind of just sat there except for the time I mentioned breaking it out.



To the original question of the thread: I wouldn't recommend lapping stones on an EE. I've never experienced diamond strip on the finer plates from lapping; but I've only ever VERY lightly used anything above the 325 for even raising slurry; much less lapping... as DMT cautioned against it due to potential stripping of diamonds.


I ran a few tools on mine on arrival to "break in"... but we're talking a few minutes of that before I figured it was a waste of time... then I did all my kitchen knives that needed touching up. Since then it's honed over a thousand razors... including a handful of full wedges that are probably equivalent to 50+ hollow razors... but I'd guess a single knife puts many times the "break in" on it a razor would... so I'd lean towards using it to touch up your knives and maybe a few friends sets too and it'd be good to go. Chisels would probably be even better if you had a set you wanted to bring up to 8k.


Pretty sure DMT used to say they were broken in before selling... not sure if that's still the case though. Some guys did report it was still necessary for their plates even back then, but others said it worked fine oob (for knives) with no break in needed.

 

[JPO]

To the original question of the thread: I wouldn't recommend lapping stones on an EE

This was just mentioned as one possible way to level out potential high spots on a new plate.
I tried this with some of my smal plates using a black Arkansas stone. It's hard to tell how much difference there was after this treatment.

 

[Mr Kooby Shemayrew]

I’m a DMT fan and have several versions of their plates. The EEF was a big dud for me though. It did not leave edges as refined as those from the more coarse plates, and despite being so “fine” it was actually a VERY FAST cutter. Basically everything to a “T” that was said about it on ScienceOfSharp was what I experienced. And unfortunately, the diamonds stripped out of it in about 6 months of light use.

I really hope DMT could fix their production process in that one. When that plate was new and before it was broken in / smoothed out, the cutting speed was off the charts. I honestly feel that it was a bit faster than my DMT Diaflat-95 but after it you’re only dealing with 3 micron scratches and not 95 micron scratches.

 

[Eshebert]

I have the same plate in 1200, I noticed how bad it shed dark swarth (diamonds) on my stone. I did not like how harsh it was. I chamfered the edges on my 36" bench sander and made some passes on the surface to calm it down. I then made quite a few rounds on 400 and 600 wet dry. I still would not trust it for a DMT slurry on a JNAT. It will probably be my last one like it. I will stick to Atoma. IMO the China plates are considerably better options.