Gil:
Pilkjington's is fussy, as these guys pointed out. It's also the most beautiful, I think, when it comes out right. I've run into a situation where the liquid sometimes just beads up on the steel,not coating it properly. Letting it dry and putting another thin application sometimes works, but I've also had to start over with a couple of jobs. I've tried the Gun Goddess, and it's much easier to apply and never had a problem. Not casting aspersions on Pilkington's, just an observation.
400 is a good place to stop, IMO.
Craig Libhart