AwlGrip & HVLP

I'm preparing to shoot AwlGrip for the first time. I'm a moderately-experienced amateur with the paint gun, having shot miles of machinery, tractors, trailers, and even a few hot rods (with help from a pro). I have read all of the AwlGrip literature (more than once), and am fairly confident on the process, but I do have some questions pertaining to gun configuration.

I have both siphon-fed and gravity-fed HVLP guns, both rated around 11 CFM @ 30 PSI. The siphon-fed gun (cup hangs from gun) has a 1.9mm tip, whereas the gravity-fed guns (cup on top of gun) have 1.3, 1.5, and 1.8 mm tips. I have a lot of experience with the siphon-fed gun, but am not completely thrilled with it. I just posted about my troubles with that gun in another thread. I have no experience with the gravity fed guns.

I'll be spraying both 545 primer and Awlgrip topcoat with the standard converters and reducers in a climate-controlled garage. I'll be doing some practice on scrap material before I shoot the boat, but want to get some solid advice on gun configuration before I start randomly trying things on my own.

I am guessing that mixed to the standard 1:1:1/2 ratio, the 545 primer is fairly thin, and probably only requires a 1.3 mm nozzle, even with a gravity-fed HVLP gun. The Awlgrip literature calls out several different guns and recommended nozzle sizes, but it seems they are ALL pressure pot-fed systems. I do wonder why.

Has anyone here sprayed 545 or Awlgrip topcoat using an HVLP system without a pressure pot? Did you use a siphon-fed or gravity-fed HVLP gun? What tip size worked best for you, and do you have any recommendations for getting the gun dialed in quickly?

Again, I have read the Awlgrip literature carefully, and understand mix ratios, spray technique, and health risks fairly well / not looking for a lecture on why amateurs shouldn't shoot Awlgrip / just want some helpful advice to save some time with my own experimentaiton.

Thank you.

 

Follow-up:

Shot the 545 primer tonight. Had some initial problems with fish eyes / cratering on the first coat, and initially thought I may have some type of contamination problem with the new gun. I eventually realized the problem was too much reducer (I had followed the 1:1:1/2 ratio specified in the manual), and mixed up a new batch with no reducer, which sprayed just fine. Then I added about 1/3 the recommended reducer, for a 1:1:1/6 final mix, and it shot beautifully.

The next hurtle, after sanding, will the shooting some top coat!