I bought an HVLP spray gun last week and used it to prime/paint (base coat/clear coat) the underside of my trunk lid and the firewall. I am very satisfied with the results , but I noticed what seemed to be quite a bit of overspray when applying the final (3rd) coat of clear, even when the pressure at the tank gauge said 20 psi. I suspect that the regulator pressure adjustment knob was not functioning properly or reading correctly. Is this a common occurance. Is this something that would wear out and need replacing after a few years of moderate use ? The firewall turned out pretty much like glass (real nice for a first timer), but I noticed that the underside of the trunk appears to have a definite "orange peel" look (still looks nice though). What could be the possible causes of this ?

btt ;)