What should the inlet air pressure be on the FLG-3 gun with a 1.8 tip spraying epoxy primer. I used my gun today and had a hard time adjusting it. I have the devilbiss gauge thats color coded and when I pulled the trigger in to adjust it would go way down or up high. What am I doing wrong?

Would a digital gauge be better for a newbie and what inlet pressure should I use?

Clint