No, I used 500 and finer grit in the first 3 trials. I noticed no improvement in these trials. Then, I decided to start fresh with 320 grit. So in total I used 320 grit two times in 8 attempts (2 were 320 to 3000 and 6 were 500/800 to 3000)
I am using 3M 3" Sanding Discs Hookit Gold...