CO2 gas as paint propellant?

[builder77sDad]

I plan to spray paint my 1983 CJ7 with urethane enamel, using a HVLP gravity fed sprayer. I have a scuba tank sized CO2 tank, and a regulator for it. It is also possible to warm the gas (if necessary) using a heat exchanger. I see an advantage in using CO2 by eliminating water and oil in the air supply, and allowing my (crappy) air compressor to supply supplemental air to my respirator mask. I have read of CO2 for airbrushing, but not auto painting. Are there any problems I should know about, or any suggestions from anyone who has tried CO2 as a propellant?

Robert
completing Ethan's Jeep (we teased him for years about it)

 

[builder77sDad]

I should add that I have a high garage allowing plastic sheeting to wall off an area, and can also tape plastic sheeting to the floor. I will buy a zipper door to reduce dust from the side. This is a complete rebuild. All the body parts are off the frame, and have been stripped of paint and undercoating. Ethan bought an aluminum tub which has never been painted. I want all the steel (not just the visible parts) rust converted with zinc phosphate, etch primed, epoxy primed, then green basecoat, then two-part urethane clearcoat. After reading a book on auto painting, I was going to pay someone else. But ... a local auto body shop wanted $2800, MAACO wanted $1500, while a local paint supply store will charge $400 for the paint system. That's why I am doing it myself. Also, I will feel more confident about repainting scratches myself.

 

[CJ]

Like you said - I wonder about the cool propellant but if you can heat it - I see no problems.

 

[builder77sDad]

I did some research. Ten pounds of liquid CO2 becomes 87.4 cubic feet at 70F and standard air pressure. At higher pressures there would be less.

Now I see why CO2 is great for air brushing, but doesn't supply enough air for larger jobs. Oh well, it was worth looking into.