During practice, my jar ran out of paint!

Well truth be known I often mix a little hardware store paint thinner into my lacquer thinner, then thin with that. You can slow down have a look and then continue, great flow out too. Paint thinner alone flows like crazy but by itself it can crater almost like fish eyes.thus the blend.

I've never shot enamel that I can recall, on a body anyway, below 25 psi with the H. Generally I use about 30 psi.

Mr Hobby makes a self leveling lacquer thinner that is a bit slower.  

My Google reveals that slower thinner is prefered in higher temperatures and higher humidity. It is now cold in SW Oklahoma. The humdity is low, under 40. The room is between 60 and 70. I just need to have an extra bottle of paint mixed up ahead of time to guard against running out during a body shoot. That's all. 

I find pressure is critical.  Both too low and too high can contribute to two forms of orange peel.

rocketman2000

I find pressure is critical.  Both too low and too high can contribute to two forms of orange peel.

 

I just shot under the hood of my Kenworth truck with Gloss Grape and it came out lovely!! 35 psi. I cranked the Paasche H cone up to about 80-85% open to make the spray pattern even wider. Before, it was throwing a pattern too narrow at even 60-65% open. I use Number 3 needle. I might use Number 5 if I was shooting a large-scale R/C model like a boat hull. If bodies, cabs and hoods are to be painted the same color on the inside as the outside, I start with the inside first then do the outside after complete enamel curing. 

Again, I use old-fashioned Testors enamel in 1/4-oz jars with 1:1 Klean-Strip Lacquer Thinner with tan, not Green, label. The beauty of this paint formula, besides a nice finish that's hard to botch, is that it also keeps inside the jar with lid sealed tight. I don't have to dump it out after a spray session and waste materials as with acrylics and others. After spraying, I flush the airbrush with plain lacquer thinner into a large used paint thinner bottle. 

Seems like you might want to try a small HVLP touch up gun and shoot real automotive paint.

JonBailey

I just shot under the hood of my Kenworth truck with Gloss Grape and it came out lovely!! 35 psi. I cranked the Paasche H cone up to about 80-85% open to make the spray pattern even wider. Before, it was throwing a pattern too narrow at even 60-65% open. I use Number 3 needle. I might use Number 5 if I was shooting a large-scale R/C model like a boat hull. If bodies, cabs and hoods are to be painted the same color on the inside as the outside, I start with the inside first then do the outside after complete enamel curing. 

Again, I use old-fashioned Testors enamel in 1/4-oz jars with 1:1 Klean-Strip Lacquer Thinner with tan, not Green, label. The beauty of this paint formula, besides a nice finish that's hard to botch, is that it also keeps inside the jar with lid sealed tight. I don't have to dump it out after a spray session and waste materials as with acrylics and others. After spraying, I flush the airbrush with plain lacquer thinner into a large used paint thinner bottle. 

 

Often the hobby compressors can't keep up with high pressure and that #5 needle, especially tankless compressors.. Just sayin, make sure your compressor is up to the task before shooting a body if you want to move to a #5.. You don't have to do as I say just putting it out there. I use an 8 gal portable compressor which can shoot all the way up to a standard LVLP gun. I have a small LVLP gun too, used only on diarama painting etc thus far. But point being it has no issue with the H and #5 but I haven't used the #5 in probably 3 years now. In fact for a year straight I shot with the #1.

oldermodelguy

I have a small LVLP gun too, used only on diarama painting etc thus far.

That's an even better answer than my HVLP suggestion.  I often overlook the fact that many are working with small compressors vs a supply line plumbed from a large garage compressor.