Heat the paint........old painters trick. Works on gelcoat and rattle-cans too. If ambient temp is below 70f, I set the gallon of paint in a pot of boiling water (crack the lid). The guys at Prestec tell me their product should not be thinned. I'll be spraying gelcoat next week and max temp is 50'ish. Even with spray booth heated to 70, that doesn't last long with the exit fan on and remember the sudden release of pressure (at the nozzle) cools the product even more. BTW, this is what causes little water droplets to be sprayed onto your paint (if you don't have an adequate dryer)....... I'll be heating Prestec next week and will report back.
JJ