I am planning a complete repaint on my 1980 this spring
and want to get more air power. I put together a basic
black pipe air distribution system and connected the
compressor in the garage which has a max operating
pressure of 125 pounds and a 60 gallon tank. I also added
another outlet in the pipe to connect an air line from a
second compressor located about 60 feet away.
It is also rated at a max pressure of 125 pounds and
has a 30 gallon tank.

Question: Do I need a check valve at the outlet where the
second compressor's line connects?

 

With a tank that size your 60 gal compressor should keep up to the paint gun. What is the HP of the compressor?

I have a 5HP( advertised) direct drive 30 gallon compressor that primed the car just fine with a HVLP gun. the COmpressor actually shut off a couple of times.

 

LIke Mike said one 60 gallon compressor should have no problem keeping up. The in thing now is the LPHV guns. I used one and loved it. 40 psi supply, pressurized can and the paint covers really well.

 

I'm not going to claim to be a proffessional on this topic, but I would think that the pressure will balance out between each comp. making them both run for equal time. My guess is that by adding a check valve one will end out doing more work than the other. I would just plug them together and go.

 

what CFM and at what PSI are you trying to obtain? and what does each compressor produce?

 

The 60 gallon compressor is a Campbell Hausefeld, rated at 10.3 CFM
@ 90 pounds. The 30 gallon compressor is 26 year old Campbell
Hausefeld rated at 9.7 CFM @ 90 pounds.
The air capacity problem is apparent when I am using
a D/A. The compressor runs almost continuously. For painting, I
use Accuspray HVLP guns which are pressure feed siphon type guns.

The compressor does cycle on and off when using the spray guns.
I thought using the two compressors when using the D/A would make
the 60 gallon compressor last a lot longer. Also should minimize any
air volume changes when using the spray guns.

 

i gave up using a d/a sander because i could never get enough air pressure to make it work right....i went right to an electric sander....now that i have a monster air compressor 175 psi....17 cfm at 125 and i figured that old d/a sasnder i had would work well so i dug it out and tried it.....nothing it wouldn't do crapola....so i tossed it....the electric one i bought worked great....

 

Sounds like your compressor needs a rebuild.... but an HVLP gun will draw less than a DA sander.

 

I do not think a check valve would be needed or wanted. When doing light work I would expect only one of them to kick in. If it's able supply more air than what's being used, the second compressor should not even come on. Due to the noise I would not want to hear two of them unless it's necessary. By not having the check valve(s) you will increase the capacity of the tank.