Thread: DMT WTF

So I'm lapping my Chinese 12k with a brand new D8X in the sink under a constant stream of water, and after a few minutes of going at it I pull them apart and look what happened! It looks like there is a raised diamond or something that is roughly abrading one spot. The rest of the surface? Nice and smooth. I even "broke in" the DMT beforehand by running a screwdriver over it a whole bunch of times. And I checked the surface of the DMT, it wasn't damaged at all, the look and feel of it are still there.
So what happened? Still need to be broken in?

On top of this, I've only had it for 2 days and I can see rust developing on it! Rust! On the honing surface, and sides! I even dried it with a towel after I was done with it! I didn't use a hairdryer or anything, but there weren't any water beads when I put it on the table to dry.

I contacted the online retailer (a very reputable one, won't name it publicly) about the scratches it was putting on my stone and was told that, "this happens from time to time" and to just "use it till it goes away." As to the rust, I was told that this is only a cosmetic issue and won't affect its use.

Please someone tell me this is normal!!!
As you can probably tell, I'm pretty p*ssed off right now.

The rust is normal.

Try finishing it with a d8c. In fact, I'm not even entirely sure those scratches even affect your hone. I could be wrong, but I'm not sure the hone is all the worse for it.

Honestly, yes it is normal. "Use it till it goes away" is correct and both of mine initially rusted a little and then never did it any more. I don't know why the rust stopped. Regarding the scratches, yes it must be due to a couple of raised diamonds on one end. You can either try to break it in more or just live with it. The scratches in the hone will not affect the function of the hone, just its cosmetics.

I'm sure you're not happy with it now and maybe your vendor did not try hard enough to convince you, but your DMT will be fine soon!

Originally Posted by Leighton

Try finishing it with a d8c. I actually wouldn't have used the d8x on a chinese 12k. D8X and XX would be reserved for the most stubborn of ceramics.

Actually, I'm not sure what a D8X is. The D8C is 325 grit and the D8XX is 120 grit. I haven't heard of the D8X. I do disagree about restricting the D8XX from the Chinese hone. Personally I think the D8XX is the only appropriate diamond plate for lapping hone.

Originally Posted by Utopian

Actually, I'm not sure what a D8X is. The D8C is 325 grit and the D8XX is 120 grit. I haven't heard of the D8X. I do disagree about restricting the D8XX from the Chinese hone. Personally I think the D8XX is the only appropriate diamond plate for lapping hone.

D8X is 220 grit or thereabouts. Your right, the D8XX is probably the only true lapping stone among the diasharps. However, DMT recommends the Duosharp line for lapping waterstones.

+1 on rust. hasn't gotten worse.

I used a D8E 1200 for my lapping after lots of recommendations here. SLOW!

I tried lapping a spyderco UF on a d8e to get a more polished finish on the stone and I got some brownish slurry after a few circles. I stopped immediately. Do not recommend using the d8e at all for lapping anything after that experience.

Thanks guys. It is good to know that the rust is normal. Frankly, I was shocked when I saw it.

And I went back and ran a screwdriver over it about 200 times. It scratches a lot less now. I'll do some more in the morning, hopefully I can get that one rough spot out.

Hold on. The diamonds are embedded in nickel. Does nickel rust (at least that quickly)???

Are you sure the surface rust isn't swarf from stuff you used to break it in? A scourer and powdered cleaner might get rid of it.

Yeah, those gouges will fade with time, I even did the same "break in" type routine as you and had the same results. I fixed that by quick-lapping a spyderco hone.

As far as the rust goes, I had the same problem and it stopped as well.

To minimize development of further rust, I also let my DMT dry resting on edge after I run it under hot water and scrub it a bit, so there's no chance of pooling and the water evaporates faster.