Thread: Lapping a Shapton

From the FAQ at the Shapton site:


Q: Can Shapton stones be flatened with sandpaper on glass the way regular waterstones can?

A: The short answer is yes, they can be flattened with that method. There are some issues though. #400 grit seems to be the limit of the paper before it begins to clog. The engineers at Shapton want a smooth reflective surface on the stones from the #5000 up to the #30000. The fine grit powder that Shapton manufactures for the lapping plate is about #4000 grit. The best performance from the stone is realized when it is very flat and smooth. It will stay flat much longer this way because the cutting particles are supported by neighboring particles. If the surface is rough, the particles at the top of the ridges will come away very easily.

Doesn't this passage refer to the old lapping plate and not the GDLP?

edit:
According to this post, it's 325 grit

Originally Posted by Chris L

IIRC the GDLP lists a grit range on the plate. Much coarser. Current GDLP owners? 250-325 grit if memory serves?

Chris L

You're right Chris. They are 270/325 grit (54/45 micron).

Originally Posted by Chris L

I've never used the Norton lapping plate so I refrained from even speculating on whether or not it would work on the Shaptons. I wanted to say that I would assume the surface it would leave would be too coarse, but Glen came to the rescue on that.

I used SteveS Norton Lapping Plate when we had our Northern California SRP Meeting. It worked great. I was surprised at how off my two new Norton's were. The only trouble is it left both feeling very rough. I went back over the 8k with the 4k. Maybe not advisable, but it felt better to me after that.