Thread: Shapton Glass Stones and swirl marks after lapping, am I doing something wrong?

Originally Posted by Charon

I was cleaning the GDLP after lapping every stone. Looking at the swirl marks it seems like there was/is a bit of grit stuck in a few very specific spots. Or a sharp point on the plate, as the scratch pattern is a whole bunch of figure 8's centered in one spot.
Which you would get if there was a bump on the plate that did not move, alot of the stone is flat and swirl free but the same location in other stones has the figure 8 swirl.

I took a dry stone and put it on the Dry DGLP and shifted it side to side by a few MM, And I could see what looked like the "spot" that may have something stuck or sticking out in a few points. I cannot feel it but it leaves a mark on the stone and I can see some residue from the stone on the GDLP.

Is it possible something is stuck in the DGLP causing this? If it was just lack of water or general swirl marks that were consistent over the entire stone I wouldn't question it so much. But the swirl marks are centered in an area and are consistent with there being debris fixed to the DGLP.

High spots on the plate will scratch like this.