Thread: DMT NEW PROBLEM.

THE only reason i am posting this message to let other's to learn from my mistake and hopefully no one else after reading this will not do what i have done.
I bought 3 DMT's after seen how they perform on Mr JOKE1176 home.They were DMT 325 grit,DMT 1200 GRIT AND DMT 8000 OR rDMT8EE.
After getting them i did brake in and start using them.i used mostly for lapping purposes dmt 325 and for razor's rest 2.Recently i think i got a little lazy and decide why not to use all my DMT'S for lapping in order 325,1200 and 8000 or 3 micron one.I thought this will be a lot easier and fast.Turned out the first hone i wanted lap was my Charnley forest stone.
1 st i used 325 and get very good surface
2 nd used 1200 and stone is getting better and slurry comes out of the stone is milky color i am very happy job is going pretty smooth
3 rd and last i try my 8000 stone .
After 5 minuts work on 8000 DMT color of the slurry start to changing black???
what is it?i get confused this isn't slurry i used to have.
checked DMT SURFACE IT very shiny hmmmmmmmmm.then i switch back to 1200 dmt slurry changed to milky color then i relise i have done some damage to 8000 dmt.Unfortunately this is the most expensive one and i just ruined it?
i did Call DMT CUSTOMER SURVICE AND very nice Person by name STAN Watson return my call.We Talk and he did promice me help to check the stone.
I don't think dmt could be defective i think 8000 was too fine for lapping.Now i have send dmt to them and wanted to wait result first then wright about this accident but decide will better let it go now this may save someones stone.
good luck and enjoy with honing experience.

That's odd. I would have thought there is no way to ruin a diamond stone. Too fine and maybe it would be not be effective or take forever but I don't know why it would ruin it?

Get a glass bottle from somewhere. Rub the DMT against the bottle. As long as it still scratches the glass (makes it milky looking), the diamonds are still abrasive and the hone is ok.

They are good people at DMT. I sent a hone back to them and they replaced it. I don't know if the 8000 is suitable for lapping but thanks for the heads up.

Jimmy,

Having opinions on nearly everything, let me share one with you. I think it's completely unnecessary to go as fine as an 8K grit when lapping a hone. The 1.2K grit should polish things up just fine after your getting the hone flat with a coarser lapping medium.

$0.02

Originally Posted by Bruce

Jimmy,

Having opinions on nearly everything, let me share one with you. I think it's completely unnecessary to go as fine as an 8K grit when lapping a hone. The 1.2K grit should polish things up just fine after your getting the hone flat with a coarser lapping medium.

$0.02

+1 I agree with you 100% Bruce. I have never gone over the DMT 325 with the DMTs. I don't know what the Shapton plate is but I use one or the other.

this is what i was thinking
DMT's is the hardest stones will lap everything
wanted have perfect lapped stone
thought DMT has diamonds all thickness of the plate not just surface
Of course after learning lesson i would never use 8000 stone for lapping purposes
Thank you all and learning still continues.

This excerpt is from Craftsman Studio - Blog · Sharpening - Diamond Products (my highlighting)

• Flattening Waterstones: Customers often ask if it is appropriate to use DMT DiaSharp 8” diamond plates to flatten waterstones. On the surface this seems like a good idea, but in practical application, only the DMT Dia-Sharp D8XX 8×3x3/8 in. Diamond Plate is suitable for some waterstones. This is because the diamonds are large enough to create an “air break” between the surfaces of the waterstone and diamond plate so the two don’t stick together due to the surface attraction of the water. It should also be noted that waterstones will quickly remove the nickel holding the diamonds in place on finer DMT plates.

My thought is that the nickel surface on the higher grit DMT's is closer to the waterstones by enough to allow the waterstone's slurry to cut into the nickel. I'm guessing.

Please let us know what the DMT rep says,

So we can't lap our waterstones (naturals I speak of mainly) with the Shapton DGLP, we can't lap our waterstones with the DMT D8E or possibly even the D8C. What CAN we lap our waterstones with?

I sound like one of those infomercials overdramatically shrugging my shoulders with a look of utter despair on my face.

I have had no problems lapping using my D8C or finish lapping with the D8E although overall, I don't lap the naturals that often. The D8XX is a great lapper although the scratches it leaves are unacceptable to me for mid and fine grit stones.

I could see how stones could wreak havoc with the D8EE though. I use a lapped 8"x3" belgian blue if I want a nice smooth surface on my stones.

Chris L

Chris,

Here is the FAQ at the DMT website. See #18 for their recommendation for flattening Japanese waterstones.

When speaking to their rep on sending back a plate that wasn't up to spec for flatness I told him that I used the 325 for waterstones and he didn't say anything at all to discourage that. So far so good with the D8C and GDLP.