I just purchased the Astro Pneumatic Evo4014 LVLP gun. I understand everything that the manual is talking about expect where it refers to the Air Adj. Valve (at the bottom of the gun right beside the air inlet). It says in the instructions:

Pull the trigger and adjust the dynamic inlet pressure: Evo-T 15-23 psi. There are several says to do it (Note: The air adjusting valve set must be fully open for maximum efficiency).
i) Adjust the pressure using a micrometer directed connected to the air nipple
ii) Without a micrometer, roughlyset the required pressure from the source and compensate the pressure drop about 9psi higher per 10 meter.



I am thoroughly confused about this. I painted my base coat today just using an old fashioned regulator. Please advise on how I should be setting up the gun for clear.

I've never used that gun but I have used other guns with the same config and I will bet that all you need to do is back that air valve out until it's wide open. Why would we want to set the PSI at the gun handle, THEN restrict the air volume with that knob? There must be a good reason why manufacturers put that knob on the gun; I've always ignored it myself and left it set wide open.

Jim ('68 Coronet R/T) owns that gun and he may be able to give you some pointers on dialing it in for clear. IIRC, he got very good results with that gun. I'll shoot him a PM and ask him to comment.

-Chris

So you're saying loosen it all the way? so it's only being held on by a thread or two?

Set it and forget it. You want that valve full open like the manual says for maximum efficiency.
Also you will notice that the charts they give show the atomizing pressure at 25 psi (at the gun) with the trigger fully pulled. I found that my EVO worked best in the 22 -26 psi range for most everything I sprayed with it.
Use masking paper on the wall and dial in your spray pattern until you get consistently fine droplets throughout the pattern with a 1 second pull of the trigger full open. I like to count 1/1000th which takes approximately 1 second rather than a quick pull and release.
The gun will only spray about a 6-8" length fan and needs to be about 6" and perpendicular to the surface when spraying.
This is a spray pattern from the EVO4014:


If you like the way the EVO sprays then you will LOVE the Iwata LPH400 when the time comes to upgrade.

dew1989 wrote:So you're saying loosen it all the way? so it's only being held on by a thread or two?

I'm wondering about this as well. The gun arrived with it fully threaded in. So by full open, do I loosen that bolt all the way out until I hear air leak and then tighten until it is now longer leaking?

equalme wrote:

dew1989 wrote:So you're saying loosen it all the way? so it's only being held on by a thread or two?

I'm wondering about this as well. The gun arrived with it fully threaded in. So by full open, do I loosen that bolt all the way out until I hear air leak and then tighten until it is now longer leaking?

I haven't used that particular gun, but on every one I've used the air valve can be opened fully without falling out. It isn't like the fluid knob that unscrews fully, but is held in place and usually has to be removed as part of the air valve assembly by undoing a seperate nut with a spanner/wrench.