12 psi at air cap = ??? at regulator

[Reamer]

Hi All

I have a finishlie 2 HVLP, the primer direction say "12 to 14 psi at the air cap"
What should I set my regulator on the grip of the gun to??????
Thanks
Reamer

[Len]

Hi All

I have a finishlie 2 HVLP, the primer direction say "12 to 14 psi at the air cap"
What should I set my regulator on the grip of the gun to??????
Thanks
Reamer

To be HVLP it should be 10 PSI or less at the cap. To achieve this you set the inlet pressure at 23 PSI with the trigger pulled and air passing through the gun.

[sperkins]

To be HVLP it should be 10 PSI or less at the cap. To achieve this you set the inlet pressure at 23 PSI with the trigger pulled and air passing through the gun.
Len,
Bear with me for a stupid question. If the gun requires 10 PSI at the tip, why would you set your regulator with trigger pulled at 23 PSI? Doesn't that give you 23 at the tip? Wouldn't that mean with the trigger not pulled your regulator would be set somewhere around 35-40 PSI?
:confused:

[Len]

Len,
Bear with me for a stupid question. If the gun requires 10 PSI at the tip, why would you set your regulator with trigger pulled at 23 PSI? Doesn't that give you 23 at the tip? Wouldn't that mean with the trigger not pulled your regulator would be set somewhere around 35-40 PSI?
:confused:

No, when you use the gun manufacturer's recommendation for inlet pressure you will get 10 PSI or less at the tip when the gun is in use. This is the law and since the gun needs to follow the law to be HVLP, you'll find that this is the case with all HVLP guns. They (HVLP guns) need to have a "transfer efficiency" of 65% and 10 PSI of air pressure at the cap when they are being used.

[Emmasis]

No, when you use the gun manufacturer's recommendation for inlet pressure you will get 10 PSI or less at the tip when the gun is in use. This is the law and since the gun needs to follow the law to be HVLP, you'll find that this is the case with all HVLP guns. They (HVLP guns) need to have a "transfer efficiency" of 65% and 10 PSI of air pressure at the cap when they are being used.

Is there some kind of formula for this?

[Len]

Is there some kind of formula for this?

Every different model spray gun is engineered differently so the amount of restriction between the inlet and the outlet pressure can vary from gun to gun. The only info you need to adjust the gun properly is the inlet pressure, the outlet pressure should take care of itself.