If your rub has much sodium in it, I'd be careful to not leave it on much longer than 2 hours before going on the smoker. Some leave it on over-night. I usually do it right before lighting the fire, so for me it's usually about an hour...
Hance - Lake Dogs Cooking Team - MiM/MBN/GBA CBJ and comp cook
Lake Sinclair, GA (strategically about an hour from everywhere)