When I was first given a spray gun they handed me a JGA-502 gun then turned away and closed the booth doors. Years later someone told me the distance between the gun and the substrate should be the distance between my extended pinky and thumb, which is 8-7/16”. Thanks to an application tip from the people at SATA, I have learned a better way to establish the proper gun distance.
To establish this distance without spraying yourself try this technique. A properly adjusted gun needle will allow you to just pull the trigger emitting only atomizing air without any coating. Now move the palm of your hand in and out in front of the atomizing air and feel when the air is flowing off your palm and not impinging into your palm. Now you have a visual distance for proper gun distance for your specific make and model of gun.
Handle: news/proper-gun-distance