Hey - I'm in the same boat as far as being back from a long hiatus. The HVLP guns use a higher volume of air as opposed to a higher pressure. This equates to more material on the car and less in the air. A better explanation is here-
http://www.stovebolt.com/techtips/hvlp_paintgun_basics.htm
Other helpful places to ask ?'s are-
http://p2forum.proboards56.com/index.cgi
http://www.autobody101.com/forums/
Your compressor will work with some of the smaller touch up type guns (Iwata lph50/lph80) that are low CFM guns and maybe the Iwata 101 or 300. Larger guns need more volume and your compressor will run constantly to try to keep up and will eventually run out of air. Some of the larger guns take 15+CFM's which your compressor will not handle.
If you are painting whole cars that compressor will be too small. If you're doing motorcycle tanks, helmets, touch up work, flames on existing paint jobs you'll be OK.
Also--Make sure your compressor is capable of a true 8.5 cfm's because some of the compressor manufacturers inflate their numbers (pun intended). Generally 1 hp from your compressor equals 4 CFM so unless your compressor is over 2 HP your CFM # may be listed higher than it actually is. I use a 4.5 gallon Ridgid 1.8 HP (CFM at 40 is 7.6 I think) twin tank for airbrush work and I also use it for priming, painting and clearing motorcycle tanks and helmets. It will usually kick on once or twice when I spray clear or primer but it fills back up super fast and never runs low on air when I use my mini guns. I've used a sharpe finex 100 and a Devilbiss SRW (great gun BTW) with it recently and it had no problem. I'll be getting an LPH80 soon also. I wouldn't want to try to paint a whole car with either gun because the fan to small.
Using a smaller compressor like the one I currently use is not the best way--I am currently in an apartment without a garage so I needed something small that was portable. I have a friends garage to use to spray the primers/bases and clears but I do the airbrush stuff at my apt. My friend and I are in the process of getting a larger compressor for the garage.
The non compressor guns you are talking about may be the turbine guns. I've never used one so I can't help. They are $$$ though. I'd rather just get a bigger compressor.
Good luck,
AJ
