Marv,
You might ask Howard Rush about this. I think he's tried several non-catalyzed clearcoats, with ah, varying results. His current orange impact is done with some non-catalyzed, urethane DuPont product that he says is not very fuel proof. which is why he's always rushing to get it wiped off immediately after a flight.
I shot a profile with Deft urethane clear gloss from a rattle can (over dope color). Worked fine for me.