I am assuming you mean the air pressure. How high? I usually use 45-50 psi. I was told by the paint rep when I bought the hvlp gun that it worked better when used with higher pressures than recommended. The rating is for epa reasons(from what I have heard) and does not give the best atomization and smoothest coverage. I found this to be true.
You didn't state whether it was gun or a system. I use a TIP hot air HVLP, it heats up and dries the air, it took a few times to get the mixing correct, I had to thin it a little more than what the paint mfg.'s suggest but it shoots like glass now. It wouldn't flow out as well on the metal at regular mix.
[ April 04, 2003: Message edited by: woodz428 ]</p>
May need to thin your paint some. also if you adjust it to make a larger fan pattern you will need to increase the air pressure. Get a gauge and small regulator to put on the gun its self makes it easier to adjust. Also last thing is make sure the little vent hole on top of the can is open and clean. Is it siphon feed or gravity?