Low Air consumption Gun / small compressor ?

[Doug C]

My compressor is: 21 gallon, 3hp compressor (Centra Pneumatic brand) that has a working pressure of 115psi and flows 3.5 scfm @ 90psi / 8.8 scfm @ 40psi ?

New spray gun I'm considering: Operates on only 4.25 CFM at 30 psi, advertised as being ideal for small home type compressors.

Will this work better than the purple harbor freight gun (12 scfm @ 45psi./ air pressure range of 15-45psi) that I used to spray epoxy primer? I mean that one had the compressor running most the time. Turned me off the idea of painting my own car with my current compressor - that was before I came across this low air pressure option. Thoughts?

Doug C

[Doug C]

by the way, the AU paint I'm using calls for 8-10psi @ cap for HVLP guns.

Doug C

[Doug C]

ok so the HF gun flows 8.8cfm @ 40psi ... my paint requires only 10psi at nozzle, so 8.8cfm divided by 4 = 2.2cfm's @ 10psi.

low CFM gun flows 4cfm @ 30psi ... my paint requires only 10psi at nozzle, so 4cfm divided by 3 = 1.33cfm's @ 10psi.

Is there enough of a decrease in cfm's between 2.2 and 1.33 to be a significant improvement? I'm just trying to paint my car without having to stop and let the compressor catch up the whole time. I got dry spots in my epoxy primer with my HF gun and current 3hp 21gal compressor.

Doug C

[Mike Fisher]

1.33/2.20 = 60.45% so that is a significant difference, but I still doubt you'll get your compressor to shut down while you're still spraying?
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[Doug C]

I do have an extra 11gal tank I could hook up to my main unit (though I don't actually know how to make that happen yet), which would bring me to 32gals total... I suppose that couldn't hurt, but again is it even significant enough to matter?

Doug C

[Doug C]

I'm thinking of completely painting the hood, trunk lids and doors together on the first wave of painting (with the rest of the car masked off) ... then wait for that paint to dry (hours, days?), then mask up those items and unmask the rest of the car and spray the main body. That way I can break the car up into sections so that my compressor can handle it.

Any recommendations for this procedure? How long to wait between sections (no booth oven)? what type of masking material for recently painted panels (paper,plastic), etc.?

Doug C

[jspbtown]

Just a solid color right? Shooting metallic would be a no no this way.

But yes...you can do it this way. I did it this way on my son's 3000GT. I actually painted the front bumper, hood, roof and rear bumper, then did the left side and then the right side. That car had many natural seams that allowed for painting in segments. Some cars don't though

The paint you have will tell you when you can safely tape. And use the correct type of tape. I also used plastic sheeting I got from either Lowes or Home Depot to mask the car off. It is 3M plastic and it is a very clingy thin film that works great for covering large areas with minimal taping.

[Doug C]

Yes, solid non-metallic and single stage paint. My car has very few natural panel breaks actually. Which is why I mentioned just the doors, trunk and deck lids. I'd love to be able to do the roof separately too.. but not sure I could do it without an obvious tape line.

To eliminate a tape line isn't there a way of taping so that the initial spray leaves a slightly faded or gradual edge, no hard line (pulling the tape back on itself, lifted on one edge).. would the paint blend into itself when wet is sprayed onto the dried faded/gradual areas? Again non-metalic acrylic urethane single stage. Thanks for the help guys!

Doug C