Thread: Did I ruin my brand new DMT-D8C?

Originally Posted by Utopian

If the slurry coming off is black, then that is the nickel plating substrate, that hold the diamonds,

Good luck!

Exactly. Black color is so obvious there is no way you can miss it. as soon as dmt touches stone that black color coming out.(of course if t is already bad)
Now another easy way is put it under light and if dmt particules gone that spot will be shiny same as mirror.hope this helps.

Originally Posted by hi_bud_gl

Now another easy way is put it under light and if dmt particules gone that spot will be shiny same as mirror.hope this helps.

If you look at my 2nd picture there is a spot right in the middle that is shinier than the rest. That didn't go away with cleaning.

Lucky for you that spot is small enough to be irrelevant.

I forgot to mention this before, and neither did anyone else...

That region that was loaded up was not cutting, so you were just wasting time and effort lapping with the plate in that condition. I suspect that the reason that this build up happened in the first place is because you were not getting enough water between the plate and the hone. Make sure you have a sufficient stream of running water and make sure to hold the plate in such a way as to direct the water between the plate and the hone. If you ever see the beginning of this sort of build up again, immediately stop and clean the plate, like you already did, before resuming lapping.

Originally Posted by Utopian

That region that was loaded up was not cutting, so you were just wasting time and effort lapping with the plate in that condition. I suspect that the reason that this build up happened in the first place is because you were not getting enough water between the plate and the hone. Make sure you have a sufficient stream of running water and make sure to hold the plate in such a way as to direct the water between the plate and the hone. If you ever see the beginning of this sort of build up again, immediately stop and clean the plate, like you already did, before resuming lapping.

Like I mentioned in another thread, the lapping took forever on the Swaty, but it did eventually erase the pencil lines I drew on it. I did the Coti after the Swaty and it also erased the pencil lines but didn't take nearly as much work. I suspect there was still some limited diamond exposure that got the job done.

I probably did not give it as much water as I should.

I use the DMT 120 to flatten all my stones, than lap the 4k+ stones with the DMT325 to smooth em out a bit. I'm just starting to get the Shapton 3k glass stone out to polish the 10k+ stones. Seems to work very well so far.

The DMTs do need a breaking in period, I've been using them to flatten my stones for a couple years now. They do seem to wear down and get finer as the abrasive wears down. When I used the 125DMT to re-profile a knife, soon after I got the plate, it gouged deep trenches in the knife. Now that it's well broken in and all it doesn't gouge nearly as much. However I ended up getting a Ninawa 125 "brick" that I like alot better for heavy metal removal.

Same thing happened to my DMT 8C when I lapped my X hone (think it's an Arkansas)

The gray discoloration never did come off even after eating thru 3 SOS pads. It still laps my Norton fine and evenly.

Originally Posted by TexasBob

If you look at my 2nd picture there is a spot right in the middle that is shinier than the rest. That didn't go away with cleaning.

There is still diamonds in that spots. when they gone it will similar to mirror.
CHECK THIS picture. this is example.i have been there.

I have seen DMT recomend rubbing the area on a glass bottle, if it frosts the glass you still have diamonds.

You could also look at the hone under magnification. Even at 30x you can definitely see the pattern of diamonds in the surface. Look around the edges (where it's not suspected to be worn) and compare what that looks like to somewhere in the middle (where it is suspected to be worn).

But honestly, looking at your pictures, I would say it's completely fine. I think you just broke it in a little, which isn't a bad thing at all if you plan on lapping waterstones.

Here is their official FAQ. They have a lot of good info in there.