Vent: a painter in Columbus told me to quit blocking primer with 320 and I still think he was dead wrong
This was 3 years ago at a shop off 5th Ave, and he watched me sand a fender for 20 minutes before telling me 320 was "wasting my arms." I told him I'd rather spend the extra hour than gamble on a mottled finish, and I've never once wished I'd gone coarser. What grit do you all actually block primer with?