Bought an air compressor Saturday


I went to Rural King Saturday and bought a Porter Cable 60 gallon vertical
3HP compressor model C7501 for $400. I went back and forth quite a bit and
would prefer a big Quincy compressor, or something similar two stage... But
in the end if the $400 compressor will do what I need, spare time hobby
metal working, spraying, auto body, then I've saved a some money. I already
plumbed it up so that I can connect my portable compressor to it, between
the two I should be able to get 15.4CFM at 90PSI.
My 2nd best bang for the buck was one of the 5HP single stage compressors
with ~16CFM, some were available for $800. I decided if I needed to spend
$800 I could get 2 of the $400 3HP compressors giving 20CFM @90PSI and 120
gallons of total air tank. Hopefully this will be sufficient for my needs
and last as long as I need, I doubt that I'll feel like messing with this
stuff in 10 years or so.
RogerN
Reply to
RogerN
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my rebuilt quincy is 5 hp, delivers 21 CFM at 160 psi (if I remember the specs correctly) - that's another consideration
Reply to
Bill Noble
That sounds like a great compressor, how much $ for rebuilt Quincy? They used to have a single stage Quincy 5HP that put out a good supply of air and sometimes would go on sale for around $600 or $700. That's what I was hoping to find but no luck. It's likely that after I get done messing with auto body work I probably won't need a huge compressor, so I'm hoping my 3HP 60 gallon compressor coupled to my portable compressor will keep me going. If I couple up enough of my compressors I should be able to get 25CFM or so.
RogerN
Reply to
RogerN
Same one I have, only it was a 6 or 7 HP when I bought it! Mine is going on 10 years of weekend warrior use, so I have no complaints. I wanted a better unit, but was short on cash, and my old compressor bit the dust. I have been watching Craig's list and occasionally a smaller industrial unit comes up, I may buy one, rebuild it, and sell off the PC while it still is running. Greg
Reply to
Greg O
Most 5HP two stage compressors are in the 15 CFM range. I doubt you are getting 21 CFM from a 5 HP unit. Greg
Reply to
Greg O
ok, that is an interesting challenge, so let's see
Quincy QR-25, model 325, manual dated November 1986, - flip, flip, flip - no specs in the manual - let's try on line:
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on page 5, it lists my compressor, the model 325, two stage "basic" compressor. typical HP range 3-5, bore 4.5 (LP), 2.50 (HP), stroke 3.0, 2 cylinder, 400-900 RPM, aprox shipping weight 480 pounds and this "AFCM @175 PSIG Min/Max RPM 8.3/18.64
so, I presume without measuring that I'm running at the max speed since I have a real 5 HP motor, and my cutoff is 160 psi (and said 21 CFM at 160) - this says 18.64 at 175 so, now to find that thermodynamic equations.....
oh, heck, it's too late - flip flip flip - there is another table for their tank mounted compressors, the F325 which is about what I have says it weighs 775 pounds, and outputs 17.4 CFM at 175 PSI, piston displacement is 22 CFM

Reply to
Bill Noble
The compressor I bought didn't come with any kind of regulator so I ebayed and "bought it now" for a couple industrial Parker FRL units. I got a Watts FRL for $40 shipped, new in box, flows something like 150CFM. Also found a Parker FRL with automatic dumping for $60 shipped. I plan to use one for lubricated air tool supply, another for unlubricated air for spraying, tires, etc. These industrial FRL units were cost competitive with hardware store regulators and filter.
I'm considering changing to another style of quick coupler so lubricated and non-lubricated lines won't be compatible, thought it might be bad to use an oily air hose for spraying paint.
There are still 10 of these available.
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This is the one I bought with automatic dumping filter.
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RogerN
Reply to
RogerN
So wadda saying? That I am correct in saying your compressor does not put out 21 CFM? Not arguing that it might put out 18, or maybe 19 CFM on a good day, but I still stand by my comment that "I doubt you are getting 21 CFM from a 5 HP unit." Greg
Reply to
Greg O

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