I have been painting airplanes with the $26 grizzly industrial 4oz HVLP paint gun for years, great for small projects and I just use a 60cc syringe to mix the paint with accurately in small batches.

http://www.grizzly.com/products/HVLP-Mini-Spray-Gun-with-0-8mm-Tip/H8224

1941 Taylorcraft
1968 Charger
1994 Wrangler
1998 Wrangler
2008 Kia Rio
2017 Jetta

I didn't do 4 years and 9 months of Graduate School to be called Mister!