If your using the "rust stop" ace paint, I think it's supposed to be their version of rustoleum. I pesonally think it loses something when they add tint to it. In any event the alkyds need to be sprayed with a very light tack coat, followed by a nice even coat as soon as the tack coat drys enough that it doesn't pull of when touched lightly with your finger. I'm probably telling you what you already know, but if not, it will save you some headaches.
Chuck
Chuck