[spikedog]

What are the best size nozzles for primer, base coat, and clear coat?

[crashtech]

Fluid nozzle size is usually selected to match the viscosity of the material being sprayed. Here are some ranges you could expect decent results with, again depending on the viscosity of the particular product:

Urethane Primer: 1.4-1.7

Polyester Primer: 1.8-2.1

Basecoat: 1.2-1.4

Clear: 1.3-1.4

The paint mfrs. tech sheet will usually specify what fluid nozzle size you should use their product, as well as how much air pressure to use.

[spikedog]

Hi CRASHTECH,

Thanks for your prompt reply and very useful information.

Spikedog

[multismith]

what does 8-10 PSI at the cap mean......I have a regulator at the base of both my conventional and HVLP to measure and have found that while under pressure the conventional 40-50 at gun inlet under pressure works well

HVLP gravity gun at gun inlet measuring 10PSI seem like way to little pressure and found that a sustained 30 PSI under load is more ideal. for 1.4 and 1.7 tips primers and base.

All material I have seen state HVLP 8-10 at the CAP......what does this mean and how does one measure CAP PSI or does this simply mean at the gun if so why not say that.

Thanks
Rick

[302 Z28]

HVLP guns have internal regulators that regulate the air cap pressure to around 10psi. Of course if you have the inlet pressure at 50psi you are not obviously going to get 10psi at the cap. I find an inlet pressure of around 20psi works well for my HVLP guns.

Vince

[Bee4Me]

The CAP pressure is measured at the tip outlet with an expensive test gizmo and as long as you run the recomended PSI into the gun or set the gun regulator at it's recomended psi,you will be in the 8-10 zone at the CAP.
This is NOT the recomended psi INTO the gun. That should be in the instruction manual.