Originally Posted by cavit8

The only thing I'd add to the list is to wash the frame with a solvent, like acetone, before sanding it. If there's gunk on the frame, you might actually sand it into the paint base (assuming you're not completely stripping the bike), affecting adhesion. Thin coats are essential, I find it tougher to paint a bike than a panel and it's easy to misjudge the spray.

As a complete aside, your post inspired me to go try "painting" a junker frame I had with asphalt undercoating. Looks pretty wierd so far...

Cam