[AT] Air compressor

[Greg Hass]

This air compressor thread has been extra interesting to me because I 
bought a new one a month or so ago. It has not been installed yet but sits 
in the middle of the shop hooked up temporarily to the welder cord. My old 
one was a Sears that I bought new over 30 years ago. It was 2 hp., 150 
psi., 20 gal. tank, and put out 6.3 cu. ft. @90 psi. . I have always said I 
would not replace it as long as it ran. About 6 weeks ago I was blowing 
dirt off of a machine when I noticed the air supply getting low. It never 
did keep up to the air nozzle competely but did do a respectable job. Upon 
listening to it I noticed that it seemed to be only pumping on one 
cylinder. I sprayed some WD-40 into the air intake thinking that if 
something were gummed up it would clear it out. Wrong. I decided to live 
with the reduced air output for a while. The next day I was using air and I 
smelled something burning. I determined the smell was coming from the motor 
but before I could do anything the overload popped. I went in for lunch and 
let the motor cool. I reset the button and the compressor pumped up to 130 
psi and the motor quit again. This time I noticed that I could not restart 
it because there was backpressure on the compressor caused by a failed 
check valve on the tank (had been replaced only a couple of years ago). Now 
we had a bad compressor, a failed check valve, a machine over 30 years old, 
and please no flames as I now see the error of my ways - a tank that over 
the years I have welded holes in the bottom of it shut on no less than five 
occasions. I decided it was time for a change.
          The compressor I bought is an Ingersoll-Rand 5 hp., 175 psi., 80 
gal. tank, 15.8 cu. ft. @90 psi. , two stage compressor. I have been window 
shopping for a couple of years. I noticed that all of the new single stage 
units have a max. pressure of 135 psi. compared to 150 psi. on my old one. 
Knowing what my old compressor could do I worried that 135 psi. might not 
work for me. My cousin bought one of these and one of his men told me 
pumping up a semi tire is a real problem as the start pressure of 115 psi. 
is only a few lbs. higher than the tire. For about $200 more I was able to 
buy the 2 stage unit ($900 out the door). It is only set up temporary but I 
have done a few things, (harvest comes first), one being, as has been 
mentioned, changing the drain. As shipped it had a radiator type drain 
underneath that once you reached under you couldn't see, plus it took a 
wrench to open it. It cost $20 but I put an elbow and some pipe plus a 
quarter turn valve on the outside where it is easy to reach. I also put a 
heavy duty regulator on it so I have a constant 140 lb. pressure. Because 
of its size, I must put it on the other side of the work bay and not under 
the bench where the old one was. I plan to run an air hose one size larger 
than the standard size over to the work bench where the hose reel is 
located. I also plan to take the regulator off the old compressor and mount 
it on the bench so I can reduce the 140 lbs.to whatever I need to paint or 
run an air wrench but at the same time have full pressure for tires, etc. 
My shop is only 24 x24 so I think the hose will work fine. I plan to finish 
installing it and wiring it right as soon as the fall work is done, but for 
now it gets me by.
Greg Hass