Grinding of a 6" f/8 Mirror
Page 2
When done with #220 grit (determined by finding all pits are of uniform size- ie no 'craters'), I went to #320 grit. This makes a big difference in the mirror appearance. The mirror starts to look smooth now, not rough. It gets a velvet-like feel to the fingers when you touch the glass, as 'soft' feeling when the finger is wiped across the surface. You can almost read large type through the glass when this stage is done.
After #320, #400 can be used, but I was out of it so I just went to 30 micron grit. This is a powdery white material. It's hard to photograph the surface, so I have no photos of the stages that follow.