JoeDirt wrote:
I know it doesn't have to be warm to blast, but it's 18°F outside and blasting is miserable enough when it isn't cold ! There's about 5 inches of snow on the ground too. I haven't tried to run the blaster with my 35 gallon compressor. I'm sure it'd do it for a little bit.

18 is a bit cool its below Dew point so you really wont have to worry so much about the metal getting damp and rusting more, Just dress appropriately.
Be leave me when I say I know Cold I used to Live in Fairbanks AK and Anchorage AK.

No your Tire inflator toy Air compressor is not up to the Job not even for 5 min.
Look for a Bigger 5-7 Hp 12-18 CFM 60-80 gal tank unit.
This is not a Cheap hobby and All of it requires a great deal of air, get a real Air compressor. what I suggested is just an entry level type machine when It comes to compressors Bigger is always better.