I did some practice this weekend, and made up a test panel with the etch, primer, base, and clear I will be painting my car with, I also wanted to get a feel for my paint gun, and how the paint sprays out and behaves. I learned a lot.
The gun I have I bought a few years ago, HVLP, it needs 8.4 CFM at 30 PSI, my compressor is not having a problem keeping up with the gun. It has a 1.5 tip, the spray pattern is very uneven, it comes out more oval than cigar shaped, and it has extra spray out the bottom, the spray out of it is a little too coarse, I think the paint droplets need to be finer.
I have a 20 Gallon Compressor, 25 gallon, 2 running HP, oil lubricated, large piston, fast recovery. 8.6 CFM at 40 psi. My compressor is able to keep up, just fine, the problem is, my gun was not atomizing fine enough. I spent a lot of time seting up, rechecking, and adjusting the spray pattern. Unfortunately I just could not get the spray fine enough, It gets finer when I turn down the mixture, but then I am hardly getting any paint, I tried higher pressure (40psi), but it did not work as well as 25-30psi. My paint calls for 1.3 to 1.5 tip, 25-30 PSI at the gun.
I ended up doing some test painting with the best settings I could manage, I ended up with a lot of orange peel. I sprayed primer, base, and clear, all with the same results.
I am almost sure it is the gun, so I went ahead and ordered an Astro EVO4014 LVLP gun from spraygunworld.com today along with a diaphram regulator for it. Hopefully it will give better atomization, also its requirements are below what my compressor can produce it is supposed to be comparable (almost a direct copy) of the Iwata $450 gun. It came highly recommended by a lot of paint pros.
Pictures of my test panel.
I tried wet sanding my test panel today (i did the right side) and hand buffed it to see if I could get rid on the orange peel. It worked ok, its a lot shinyer now. Not perfect, but it was just a test.
