#1.
When I get my car disassembled for painting 'e.g., doors, t-tops, hood and new fitted fiberglass bumper covers, wouldn't a 5hp, 8cfm comperssor keep up with all the different pieces plus the main body with all these parts removed?? Realizing professionals have high quality compressors that meet the demands of a production shop, I, in my own little shop, could afford to wait on my smaller compressor between pieces....I would think!!
#2
When speaking of sanding and grinding, pneumatic tools are always mentioned and how they will drain a small compressor. This has me wondering....why not use electric tools for these compressor demanding jobs?
Small compressors require patience while stripping/sanding.... yes you can wait but you'll hate life after an hour or so. What you don't want to have is a wait while you apply paint, or have wet air because your compressor runs nonstop and condenses moisture out in your hose because it leaves the tank hot. Moisture will ruin any paint applied even primer.
Electric sanders etc are OK but the contact surfaces are generally not configured for standard auto body size abrasives. These are shaped the way they are so that sanding happens most efficiently when used on the contours found in auto bodies.
Swirl remover is a very fine polish to minimise the circular scratches left by power polising bonnets... they refract sunlight and show the buffer marks found in poorly done buff outs.
to larry
8cfm compressor will supply enough air for a hvlp gun, but just barely, and porchdog states that the pressure and volume will vary enough to effect the gun's operation. and you should trust his judgment.
to moe
in production areas, it's safer to have compressed air lines on the floor than electric cords, plus air driven tools are (unless you buy the china stuff) are more accurately made and run smoother (less tiring).
to curly
as stated above, hides previous mistakes.
a 5 horse should deliver much more than 8cfm. unless it is a 3horse with dual starters and rated 6 hp. it will have spl as the hp on the tag. 8 will make it really tuff to atomise the paint. only an iwata will shoot that low. even then you may have problems. run a hose wide open and see what pressure it will maintain.
I have a puma rated 5 hp, 8cfm. It's a 120/220volt compressor that I was having trouble with the motor so I took it to a guy I know that rebuilds this stuff and he said there is nothing wrong with my motor that a 220 volt hookup wouldn't cure. He said if I wire it off the 120 and wire it for 220, I could probably enlarge the pully and get another 1-2 cfm out of it. He thought it was a well built unit with a good strong motor. ....but, he's not an auto painter!
rewiring it wont get you more compressor. speeding up the pump will just destroy the pump. take it to a compressor rebuild shop or leave it alone. just like turning up the pressure switch . that does nothing either except change the on and off pressure. i run my shop on a 5 hp compressor. i run air tools, air buffer, paint booth , everything. but it is just me here. add one more guy and you go to 10 horse.
Something to look at. When i buy air tools I look at the air consumption specs and try to match them to my compressor. For instance my neighbor has a bigger compressor but when his impact wont break bolts loose, he comes for my impact and gets the job done. It operates well at a lower CFM.