I'm going to experiment a bit with an inexpensive hvlp conversion gun. I've
hooked together all the pieces -gun, regulator, in-line water filter. My
compressor usually sits at 90 psi for nailers etc. so I figured I could
regulate the pressure at the gun regulator. I remember someone telling me
that around 30-40 psi was best for these guns.

Here's where I'm confused (and my vast knowledge of air pressure related
things shows through

The pressure shown on the guage at the gun never changes - same as it is at
the compressor - I shut it down at about 60 psi then played with the
regulater at the gun. The volume and speed of the air leaving the gun varies
with the setting of the regulator, but the pressure guage is always shows
the same as at the compressor guage.

Obviously I don't understand this properly. Do I need to go back to the
compressor and regulate the air pressure to 40 psi or so there ?

btw - I've been told not to get my hopes to high with the results of this
setup - but hey, the stuff is here and all I'm out is a little time and a
little fininsh to play with it.

jim