What does the top control knob do? This is a Binks M1-g spray gun. The bottom knob controls fluid but the top knob doesn't seem to make a difference on anything. I
Spray Gun Lowdown - Glasair Aircraft Owners Association
Binks 10 Litre Zinc Plated Pressure Pot Package 2 from SprayDirect.co.uk
Binks® 2100 Spray Gun, 1/4 in NPS Air Inlet, 3/8 in NPS Fluid | Groves Industrial
New Binks Trophy AA Airless Spray Gun | Aviation Pros