What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

What Spray Gun Will Work

vsavatar

Member
I'm going to prime the internal parts of my RV-10 for various reasons. The primer I've chosen is AkzoNobel 463-12-8, as I have a reliable supplier around here for it. The problem is that I have only a 20 gallon 2 HP compressor that I'm not inclined to upgrade. Assuming that most surfaces I prime are going to be small, is there any spray gun I can get that will do a decent job. I'd like to get the Accuspray, but it seems to be HVLP and requires 13 CFM @ 20 psi. The best my compressor can do is 7.1 CFM @ 20 psi. So that seems out of the question. Astro Tools has one called the GF14S that seems to suggest it needs a 3HP compressor, but the flowchart on their site also seems to indicate that if it can pull 5.5 CFM @ 50 psi, that it should be sufficient, and my compressor can pull that. Anybody that has a smaller compressor had any success with any spray guns in particular?
 
All my interior priming (Super Koropon epoxy) and interior topcoat (Jetflex) was done with an HVLP gun (similar scfm 13-14 as yours) and a 1 hp (8.0 scfm @ 40 psi, 6.4 scfm @ 90 psi, 20 gal tank) compressor. You don't hold the trigger of the gun down continuously and so the compressor can keep up. Also when spraying multiple parts, there is a natural break between parts where the gun is not consuming air. Your compressor will be fine.
 
Last edited:
determining the CFM needed has a lot of assumptions. It is really a matter of how many seconds that a spraying operation takes along with non use period and how long it takes for the air pressure to drop to critical level and then how long it takes to get it back. Rated CFM is all about long use operations and spraying small parts doesn't really fit that, as the tank capacity helps with this type.

One way to get more capacity is to increase tank size (i.e. add another storage tank) instead of a more powerful compressor. While you won't be able to spray large panels with that mismatch, you likely can spray small parts if you pause enough to let the compressor catch up. ANother option is a compliant gun over HVLP; lower air volume rquired.
 
Last edited:
My compressor was a 5 HP, 26 gallon unit rated at 6.6 SCFM at 40 psi. It was used for all of my riveting, drilling, priming and interior painting. For primer, I used a DeVilbiss standard sprayer, and a Harbor Freight HVLP gun for painting. Both seemed to do just fine. With that said, I'm no paint pro, so maybe I'm just too ignorant to know the difference. But I did all of the interior like this using PPG primers and paints. I let professionals do the exterior painting.
 
Astro EVO-T LVLP

Used for AKZO on my -8. 2.5 HP compressor 20 gal tank. Compressor ran 30 -50 percent of the time spraying big stuff like skins.
 

Attachments

  • F60747B3-B505-48EA-96B3-8C2179717320.jpg
    F60747B3-B505-48EA-96B3-8C2179717320.jpg
    787.8 KB · Views: 125
Last edited:
Spray gun

All my interior priming (Super Koropon epoxy) and interior topcoat (Jetflex) was done with an HVLP gun and a 1 hp (8.0 scfm @ 40 psi, 6.4 scfm @ 90 psi, 20 gal tank) compressor. You don't hold the trigger of the gun down continuously and so the compressor can keep up. Also when spraying multiple parts, there is a natural break between parts where the gun is not consuming air. Your compressor will be fine.

Terry is correct. You can significantly increase the spray time if you fully release the trigger at the end of each pass. I would never do it with a top coat because the sudden trigger pull can throw some droplets. For primer, no big deal. I would save some money and buy the Harbor Freight Purple Gun.
Skip the cheapo regulator or flow restrictor. Buy the adapter for disposable cups. I prefer the 3M PPS Version 1. Buy a few red disposable air/oil separators.
Buy a decent mini regulator. I love this one.
If you want a heck of a gun, buy the Harbor Freight Black Widow HVLP HTE. It really lays down paint and uses far less volume of air. My compressor run a lot less than with the DeVilbiss FLG.
 
Last edited:
I used Harbor Freight's $14 touch-up spray gun for my interior. It's much smaller than the full-sized guns and uses considerably less air. I like it a lot. The downsides are that the gun only covers a smallish area per pass and there aren't any of the 3M disposable cup adapters that I know of for it.

Caveat is that I'm building an RV-3B which is a lot smaller than your plane.

This is it. It says it uses 3 CFM at 50 psi.

I used it with Stewart's EkoPoxy primer, which cleans up with water.

Dave
 
I went with the Astro EVOT, and it worked without killing the compressor, but I did notice that around the top of the parts I was painting, that it looked like the coating was thicker. Like you could see it running down somewhat. Was that because I used too much? It seems to have adhered well after I cleaned and scuffed it using Prekote? What problems is having too much primer likely to cause, other than extra weight? Is there anything I need to do to remedy it? It was the vertical stabilizer parts that I primed. The primer I used was AKZO, as noted above.
 
I wouldn’t sweat having a few runs in your primer but you should be able to find a gun setting that coats the part uniformly. The little LVLP guns have a pretty small usable fan. Say 6 inches. Get a roll of aluminum roof flashing from Home Depot to practice on. It’s cheap and easy to prep. The pic is some flashing I primed with AKZO with that gun. It’s very uniform.
 

Attachments

  • 544FABF5-1941-4A54-9932-784813E2B582.jpg
    544FABF5-1941-4A54-9932-784813E2B582.jpg
    409.1 KB · Views: 115
Last edited:
Back
Top