I never knew that there was a "Factory surface" that needs to be removed. I will need to give this info a try. I notice on my 4k side that there are spots that seem different... more course than the rest of the surface. Perhaps this is the problem. Seems to make sense.:hmmm:
How thick is this factory surface anyway?:thinking:
I have flattened my hone on 400 and 800 grit wet/dry but only enough to get it flat.