Using air brush in the garage

Yes, you can airbrush in your garage in those temperatures, but you'd probably get better results with a heater in there to warm it up a bit. I've been airbrushing in my garages whereever I've lived for close to 30 years now. Although it rarely gets down into the 40's where I've lived when I'm in there airbrushing. Also, at the very least you'll want some sort of fan and perhaps a respirator mask to blow fumes away, depending upon ventilation in your garage, particularly with enamels.

With enamels you will do well to get the general area where you are spraying into mid 50's to 60ish F. To me enamels go on well in that temp range. You don't have to heat the entire garage. Claim a corner and set up there.

You could play hit and run, heat the paint first, have everything ready to go, head into the garage and get your paint sprayed on and back in the house with the painted model parts quickly. You need to develop a system where you don't linger around and ponder the next step. Be ready and efficient. I've done this at times even outside @30f. Usually rattle cans though, pre heated in hot water..

I never had any issues airbrushing enamels in cold temps when I painted in my Garage, in the winter time, in Ohio. It was well below 40 (upper 20's most likely) on numerous occasions and I can remember having to pour hot water over the compressor crank case to warm up the oil before it would start... Then again, my dad did have one of those jet-engine-looking Kerosene Heaters in the garage, so I can't really say for sure what the temp was when I was airbrushing...

Just get her to leave the house when you spray enamel

Hi:

      There is some problem with smell but it is slight, as to the temp, Well, I have sprayed at that temp and the paint didn't act right, So I would be careful here. Ambiant temperature can affect how paint lays down and how well it drys.

In 1/1 if forced to paint in colder than recommended temp we used a fast dry thinner. Especially with metallics, you can watch the metallic particles slide in the paint, a weird form of run if the paint doesn/t get a fast enough initial tack.

I think the question of temperature has already been addressed, but there is another issue to worry about in garages: dust in the air.

I've sprayed in garages and basements and made it a habit to spray a mist of water in the air before I paint. The fine water droplets will grab a lot of the dust from the air as they fall. And a spray bottle is a lot cheaper than buying and running an air cleaner in such a large area.