Thread: Atoma 400 lapping leaving scratch marks on stone

Make sure to break in your diamond plate, by sharpening a couple of kitchen knives on it with pressure, to remove any high diamonds, especially from the edges.

Then lap a low grit stone on it. You need to lap with pressure, then lighten up on the pressure at the end to finish. A 1k or a Washita are good finishing stones for lapping.

The brand new DMT 325 i got had several high diamonds in it that would also leave deep scratches in my stone. it took a long time of lapping and sharpening things to knock them down. Now i can't use it on my smoothest finishers and leaves a silky finish to the stone.

Rubbing the side of a screwdriver or hardened steel on the plate can speed up the break in process.
I had to use magnification and even chip out a larger piece of diamond in my plate.

these plates are tough and will last you a long time, make sure to always lap stones under running water. i have rubbed out the nickel substrate (that holds the diamonds in) by having inadequate or no running water while lapping. now there is a bare spot in the middle of a plate of mine

the 1200 can aid a little in smoothness but is not a necessity.
I would break in your 400 before buying a new plate
the swirls or scratches on your higher grit shapton shouldn't inhibit the stone too bad, you should be able to get a shave-able edge. though its obviously better w/o scrathes

I use the 600 and am happy with its results, and follow with coti or BBW if necessary (usually not).

I'm not sure if it was ever settled, but for a time there was a strong warning not to use the 1200 for lapping - something about the diamonds coming loose and being embedded in the lapped stone, IIRC.

Personally I think you'd be okay honing with the scratches but if it bothers you wet/dry may be the ticket.

I'm not sure how it effects performance

I hone with my stones lapped right off the DMT Lapping plate which is lower grit then the atoma 400.

The scratches smooth over time. If not then I've got a Belgian blue whetstone that really smooths scratches out.

Maybe that's an option for you. Good luck.

Flat is good, tiny scratches do not really matter when honing.

I use a translucent small Arkansas( ¼x¾x3")pocket knife stone to clean my stones after using and lapping.I will not shed any grit as it is harder and finer than any stone I own other than itself. Specially good for Shapton glass which are soft and wear quickly!

After the steel rub on your Atoma, try using a hard Arkansas hone to mellow it out. They will take a lot of rubbing on diamond!!

YMMV
~Richard