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

That FAQ is definitely a departure from what they had somewhere on their site maybe a year ago. I am absolutely certain that at one point, they declared that only the 120 grit XX was acceptable for lapping hones. Now, they are okay with it up to the C, which is 325 grit, for waterstones at least.

I use a DMT D8X to lap, and use a Ch12k to smooth out the scratches left by the D8X

First, sorry to take this old thread back but it has good information so I prefer not to create a new one for my simple questions. I hope it's OK.

So today I received my DMT D8C (from White Mountain Knives ebay outlet which was the cheapest I could find to be delivered to me in France). As probably any of us not having handled one before I have been quite surprised by the weight of this beast and I also noticed some rough spots on the sides of the plate (visible on the lower side on the picture below). No big deal I guess but still, I did not anticipate it.

I lapped my stone last week but on a thick glass plate with sandpaper and water going from 400 to 800 then 1000 grit.

So today I went to work and used the D8C. I first lapped my pretty new Naniwa 1K/3K and was quite surprised to see that there was a lot of work to do to wipe my pencil marks. Worst side was the 3k. Was it really that far from being flat after my glass/sandpaper lapping ?
Using the DMT to chamfer the stone it easy as pie and very useful.

Then I got to my Norton 4k/8k. I have had this one for quite some time and I once forgot it immersed for so long one that some mold developed and stained the surface. I thought I would never get it as good looking as it used to... but the D8C just made it nice and clean
This stone was pretty flat, not much work to be done but removing the stains is a just really nice !

Next up was my Ch12k and here I hesitated. Should I really use a 325 grit to lap a 12k ??? I did anyway and, the DMT being very new, I scratched the entire surface of my finishing stone...
So I did as I read some people do using the DMT as a plate for sandpaper. Using water again, I went to 400, 800 and 1000 paper. Everything went OK and the scratches are gone but that took me lots of time and efforts. (my shoulders hurt now and my left hand has some tremors since )

While drying and cleaning my stones before storing them I was disappointed to see that the DMT developed some weird circular patterns on its surface. This cannot be from my lapping session as is looks like this :

I tried to clean the surface with Ajax powder and scrubbing with an old stiff toothbrush but I did not manage to take the dark "stains" off.

So I am wondering :

- Are these "circles" a problem or just a manufacturing artifact ?
- How do I get the damn surface really clean ?
- How do one know for sure that his DMT is very flat indeed ? I searched for this one a lot and apart from DMT saying that it is flat, I have no proof so

Thanks !

I really need to take a pic of what a "Well Worn" DMT 325 looks like A sure fire no fail test is to take a drinking glass to the surface.. If the Diamonds are intact they will scuff the Glass surface a Fingernail is good but a Glass is better.. It also tests high spots

A certified Straight edge will test for flatness on your DMT..

I know this has been solved BUT ... If you put some 3 in 1 oil on the DMT and rub it in with a toothbrush it will lift everything off it rather easily.
I regularly use my DMT to lap barbers hones, natural stones, and man made stones and that's how I get the crap off it.

When lapping stones with oil in them I use a little detergent in the water, keeps the stuff from sticking to the DMT most of the time.

Thanks for for tips Glen, your videos were the last trigger that convinced me to get the DMT.
Do you have heard of a non flat DMT before ? I am not doubting about mine, just wondering if one can really trust the DMT better than say a thick piece of glass.

Hmmm, 3 in 1 oil ? I will have to give it a shot. Thanks Carl !

Originally Posted by Lemur

When lapping stones with oil in them I use a little detergent in the water, keeps the stuff from sticking to the DMT most of the time.

The problem here isn't oil, it's that the barber hones are made from a kind of clay. I am not 100% sure that it IS clay ... but it's like clay. So it sticks to the lapping stone.
The oil acts as a solvent, and it also lifts debris because of it's properties.

Originally Posted by bzhgeek

Thanks for for tips Glen, your videos were the last trigger that convinced me to get the DMT.
Do you have heard of a non flat DMT before ? I am not doubting about mine, just wondering if one can really trust the DMT better than say a thick piece of glass.

Hmmm, 3 in 1 oil ? I will have to give it a shot. Thanks Carl !

No Problem, just don't use it to hone with lol I burned my fingers trying that one out, maybe my fingers are a little soft?

Yes there are "Out of Flat" DMT's and the are warranted by DMT so if it is enough to see a gap of light under a Straight Edge then I would return it..

Keep in mind, we tend to put a bit to much emphasis on Flat, but if you pay for Flat you should get Flat...

ps: DMT makes a Plate Cleaning Kit with a Brass Brush a Special Cleanser and a Rubber in there that works rather well, I bought one off e-bay for $8 shipped...