Check with your paint supplier for the MSDS sheets.
Urethane need a minimum temp during the crosslinking period to cure properly.
If you try to paint at too low a temp. you risk having the paint remain soft , nothing you can do once that happens,just strip it off.
Also, urethanes should have sufficient air flow across the surface during drying to insure that solvents aren't trapped causing solvent " popping" which resemble blisters in the surface.
All in all it would be best to wait for the temp to be at least 70 for spraying.
It will save a lot of time (and money) in the long run!
