Oh, and I always brush it on. Use a decent brush, nice & wide 1/2 inch at least. Even strokes, and put it on evenly. Let it dry, lightly sand (with>220 grit) any bubbles, then do a second coat.
I've heard some folks say you can spray, but others I've heard say dope will stick in your airbrush and not to do it...can't really say since I don't airbrush...