Bought one brand new today. Hooked it all up. Threw some primer in it and it's not working. Air is coming out but no paint. WTF is the deal? I've fiddled with all the control knobs. Nothing. :fire:

Okay.. what sorta paint am I supposed to run through these things? I bought some Rustoleum primer that says "for brushing, rolling, or spray guns". But obviously doesn't work very well. I ran straight mineral spirits through it and it works fine. So it's the primer. I even had it cut down pretty far. :rolleyes:

The rustoleum is too thick to spray. Simple enough answer. Thin it down.

What is the tip size you are using? Most automotive primers won't atomize with much less than a 1.4 tip and some people use up to a 2.2 with the heavier ones.

As Brian_B suggested - thin it down :D

I thinned it way down and still nothing. I figured out that if I run the compressor at about 65psi it will work.

So, the gun is supposed to be at 40psi. What does this tell us?

Is rustoleum a house primer or automotive? I have sprayed house paint with a siphon feed, but never a HVLP. It has to be so thin it barely covered to spray. UGH!

In theory a HVLP gun has between 25-40 PSI in (at the gun regulator) and only 10 PSI at the air cap. That theory goes out the door unless its a high quality automotive gun like a sata or iwata (sp).


You might want to go to the hotrodders site and read the stickies on painting. It would help you a lot I think. It shows how to set the gun by the spray and ignore the pressure.

My compressor holds 120 PSI, but I regulate to spray pattern at the gun. I set the inline pressure on the high side. I have a small regulator and air guage on the base of my gun that I use for adjustment.

As Brian said, check your tip size and thin it down some more. I have a cheapo HVLP gun and it doesnt like to shoot primer.

Primiers are, as a rule, a real PITA to shoot. My best success has come from a pressure feed with primers. I am assuming your HVLP is a siphon feed? I have also learned that i prefer gravity feed on my HVLP guns.

Remember when a can of paint says spray, it might also mean the high pressure spray equipment instead of air.

For primer I use a cheap HF gravity model with a big tip. For finish work and clears I have a Sharpe platinum.