[JP_79Formula]

I have a Devillbis HVLP gun that says it should have 30 psi inlet pressure
for 10 psi at the spray cap. What's the best way set the inlet pressure?

I have an inlet gauge/regulator at the gun, is the 30 psi with the trigger pulled?
and then the pressure drop to the tip will result in 10 psi?

Thanks.

[gearbanger]

I believe that is correct, 30 psi with the trigger pulled.

[bammbam]

yes, 30 psi inlet flowing pressure at the gun (trigger pulled). This is the maximum setting. depending on your paint you may have to back off the pressure a bit, the tech sheet for the paint should give you a recommended setting. I made the mistake of setting my regulator to 30 psi and didn't consider the pressure drop for the hose.....got a lot of orange peel

[69-er]

I'm still new at this HVLP stuff, but the instructions with my Devillbis states not to use too high a pressure. Lower the better. 23 PSI is what they recommend.

Larry

[JP_79Formula]

about 20 psi seems to work for me, at 30 it's like a hurricane out of the cap.

I think the 30 psi inlet is the Maximum.

But like bammbam says, pressure too low at the inlet,
or improper fluid/air mix can ruin the finish.

[Birdguy]

The 30 psi to the gun with the trigger pulled ought to put you in the ballpark with most guns, but you still have to account for the individual characteristics of the material you are using, the ambient temperature, etc. Doing a few test-sprays on masking paper will allow you to fine-tune the gun for the best atomization (determined by air pressure and material viscosity) as well as spray pattern. When you get it looking good you can move on to the metal.

[valkyrie9901]

Pressure also depends on the orfice size.......JB.

[irgoatmike]

Ditto what Birdguy said. Every gun manufacturer has a different spec to reach that 10 psi at the cap "speed" limit to legally be considered an HVLP. Do some pattern testing on masking paper before shooting the car. irgoatmike