Gun CFM to compressor CFM output

AAE

AAE

Learner
My Lph300 needs 7.1 CFM. What is the minimum CFM the compressor needs to produce?
 
depends on a couple things, what is getting the air from the compressor to the gun by means of length of pipe and pipe size and how good your air filtering is. You do not want to run a little compressor loaded all the time because the air just gets hotter and hotter and heat is what creates the moisture. If you have a refrigerated air dryer that cools the air down past dew point consistently then a little one is fine. I like to run the biggest pipe I can reasonably put after the compressor with t fittings and drain valves to get moisture out, but those actually take cfm's away from the work.

If you can get a compressor to cycle on 5 or 6 times an hour, you are usually ok with heat and excess moisture buildup, but every three to five minutes is asking for trouble.
 
are you ready for this?my compressor is 30 gallon oilless the produces 6-7 c f m. the only piping infiltration I have is an airline going to a motor guard filter.
 
You want some head room on that CFM requirement. For that gun I would suggest a compressor that puts out a minimum of 10 CFM @ 40 psi. A larger tank will help keep the cycling rate down but to be honest about it, you really need to consider that your compressor is the heart of your shop. Just as a weak heart can hinder our performance physically speaking a weak compressor is going to severely hamper your efforts at producing quality work in a timely manner.
My personal and FREE opinion is that a one man shop would need at the very least a compressor putting out 15 CFM @ 100 psi with an 80 gallon tank. I say at the very least because this is what I have and it barely keeps up with my blast cabinet and DA. Handles my spray guns just fine however.
Also, you should have a minimum of 20' of air line before your filter/drier/water separator and then on to your wall regulator. Which in my case has another water separator and filter.
 
A one man paint and body shop needs at minimum a true 3HP or a hardware store bought "5HP" which are 3HP pumps overdriven. A true 5HP with 80 gal is best, but then you are talking real money.
 
Those CFM ratings at 40 PSI are useless, that's the pump output
when pumping against 40 PSI, which no compressor ever does
after fill up. Most tanks are kept above 90 PSI which means the
pump is pumping against that, which is quite a lower CFM output.
It doesn't matter what you're using, the pump only knows
what it's pumping against once it comes on.
 
I would not consider that compressor adequate for general purpose body shop work, but if every job is one panel, or two small panels, it might work out ok for a while.
 
This is one case where bigger really is better.
No matter what you get, you'll wish it was bigger.
I'm on my 4th compressor.
 
I'm with JC, get the biggest you can possibly afford. This is what I have and its barely enough to run my blast cabinet:
P1010007.jpg
 
Most air sanders pull around 15 CFM, my compressor is 17 @90 and
runs almost constant to power one. You want a compressor that turns off
once in a while to cool, if it runs most of the time you'll have moisture problems
that will cause problems for painting as well as air tools.
compressors can get really hot after running a while.
I have an Eaton that has a continuous run feature that allows the motor
to keep running once the pump stops pumping, the pump runs in a unloaded condition,
and eliminates all the frequent start-stops. That really helps to keep it cooler
 
i use a regulator for air tools ( da ). 40 lbs will give you more control and less heat . paper will last longer and it is easier on your compressor .
 
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