Last night I finished grinding with #320 Al2O3, began to use #500, but I suddenly found the #500 is much more rough than #320, I guess the reseller had maken wrong mark between these 2 kinds of Al2O3.
OMG! the mirror came out millions of little holes before I realized what happened after 5 seconds. I had to spend 1 more hour to smooth these holes.
You can take this as a lesson. |