Underside paint....ideas??

[Captainkirk]

Well, soon enough (I hope) my Duster will be completely treated on the underside with the flat black Rust-Oleum "Rust Reformer"/converter. The question is; what to follow it up with?
First on the auction block- Type of paint. Right now I'm battling between Rust-Oleum enamel and Krylon; both have an excellent reputation, spray well, and leave little in the way of runs, drips or errors., Yes, unfortunately I'll have to use rattle can/spray bomb-type paint....or will I? I suppose I could drag the gun under there. Seems like a waste (and unneccesary expense!) for the bottom of a car that should never see a winter's day. Anyway, I'm open to suggestions based on your own personal experience....good OR bad.....and look forward to your suggestions.
Next up; color! The drive train (differential, springs & shackles, drive shaft & trans will all be Rust-Oleum white. I was gonna do the underside in basic gloss black but I wondered (again) if any of you have tried any unusual colors with unusual results. Pix please, if you got'em!
Last but not least; I've considered doing the entire underside (minus drivetrain) in undercoating, in which case color wouldn't matter. I'm a bit hesitant as the undercoating I sprayed (30 years ago) over primer actually has rust sopts popping through (this after sitting 30 years with little or no road time!) Not a very good commercial plug for undercoating. Of course, had I undercoated over a good enamel, results might be very different. Your experiences, comments, etc? Thanks!!!

 

[2 Darts]

My vote goes toward painting the underside any color you like. How about doing the driveshaft in white and red like a barber pole?

My experience with undercoating has not been good, particularly the stuff that dries to a hard shell. First, if you get any on the exhaust system, plan on getting asphyxiated. Second, if a crack develops, the undercoating, moisture barrier that it is, holds water up against the floor pan. Rust city. Third, some of the water drains are small, plug one up with the spray and you have a portable pond. Rust city, again.

I've run across a type of undercoating that does not harden. The car had a decal on the window that said "Rusty Jones". Twenty-five years later, it was a gooey mess. While I think it would tend to "heal" rather than crack, it may take a commercial spray rig to apply.

That's my 2¢ worth. Hope it helps you decide.