when i did my second helmet, i let the primer dry for about an hour, then did 2 coats of silver. i let that sit for about 2 weeks (lack of time, not a conscious effort). then i did the base green, and let that dry overnight. i did the red, mandibles (green + blue + black, all sprayed into each other wet), and back (green) all in one night. the next day i ripped up the paint where i had masked and started the 'scratching with a pin' phase.