I can't add anything to the warnings oldred has already given.
Originally Posted by x711
For the gun I am using a finex fx300 hvlp 1.4. The gun works really well in
this setup. For this particular gun I run 70psi into the gun to achieve
the 29-psi at the cap. With the gun fully triggered there will be a pressure drop to about 2bar 29psi from the 70 going in.
I'm also a looong way from a painting expert but that 29 psi sounds a lot more like my Binks model 62 than HVLP. Just returned from a visit with my oldest brother, who has painted for a lot of years, to get some tips for using my cheapie HF "purple gun". His $400+ HVLP gun has "18 psi maximum inlet" stamped on the cap and that's just what he sets his regulator at. When he pulls the trigger, it drops to about 9 psi, which is very close to the pressure recommended in the manual for my gun and the pressure recommended in a thread in the Body - Exterior forum where a bunch of experienced painters were discussing how to get the best from a new gun/cap from some major manufacturer (Iwata maybe?). I could easily be wrong, but if I were you, I'd post those numbers in Body - Exterior and get some feedback from the experts who hang out there.