What To Look For When Upgrading My Compressor

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PostPosted: Thu Feb 18, 2021 3:56 pm
Hi Guys,

After using my new air palm sander, it is becoming very apparent that my compressor is too small (I already knew that). 20 gal. 7.5scfm @40 psi/5.0@90 psi. It does fine with painting the bike stuff but I don't think I could even shoot a car hood without it constantly running (not doing that yet but, that will be the goal as I gain more experience). Eventually I want to do complete cars so I knew I would have to upgrade for that anyway.

Now, I know that I should buy the biggest/best compressor and supporting equipment I can afford but, what specs should I look for in a mid grade set up? I don't need the best of the best but I also don't want to spend and just get the bare minimum. I'm not running a shop so it would only be one tool running at a time. If I have a good idea of what to look for, I may keep my eye open for something used. I do already have 220 volts in the shop for the hoist and my welder, so in that way I am set. Thoughts??

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Location: ARIZONA
PostPosted: Thu Feb 18, 2021 5:47 pm
Mine is a 6 hp 2-stage 80 gallon unit that runs on 240 Volt.



It is the smallest I would recommend for a 1 man shop. I can run my blast cabinet with it but it runs constantly.
BB-1000XLD-1jpgw240h324.jpg (13.67 KiB) Viewed 394 times

I run the air through a flexible hose and then through about 30' of 3/4" copper line, an M60 filter and into this refrigerated drier:
Speedaire.jpg (7.22 KiB) Viewed 394 times

Then through another 20' feet of 3/4" with a drop valve on it just before it goes into the booth. In the booth I have a water separator/regulator then another filter and shutoff valve to the airline.

Being in Arizona I only have to turn the refrigerated drier on when the humidity is up - not often.
1968 Coronet R/T

ACTS 16:31

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PostPosted: Thu Feb 18, 2021 6:49 pm
First thing is to look at the electric motor and see if it's big enough to turn the compressor at capacity without stressing out. This is the most difficult thing to do because specifications vary wildly. Start by looking at the most expensive brand out there, then compare to one of the cheaper brands. You'll see that the better brands nearly always have a much bigger motor than the cheap brands which are specced to "just make it". Problem is that a motor that's running at full capacity won't last as long as one that's not over stressed. Look at volts and amps for the electric motor, not the plucked out of the air hp figures.

Then look at the capacity of the pump. Around 500l/m or 17 cfm is comfortable for most use although air sanders run flat out will push this to the limit. 21cfm is better. Remember these capacities are 'free air delivery'.

Next is tank capacity. Within reason, bigger is better, but 50l/12gal is the bottom end and over 100l is ideal. Capacities are in litres of water, not what might be possible at the bottom of the Marianas Trench. If the tank is about 5' high and 2' in diameter then it's probably big enough. A bigger tank gives the motor and pump time to recover and allows more cooling of the air (although never quite enough).

Consider noise. Some compressors are very noisy and running in your shop may drive you nuts, not to mention complaints from the neighbours. Have a look at the new generation of "silent" compressors. They're a bit more expensive but what price your house, your sanity and your marriage?

Buy the best brand you can afford. It will pay you back in reliability and long life.

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PostPosted: Thu Feb 18, 2021 7:54 pm
I just bought one for my new shop and got a Quincy! Made in the USA!!!
Great ratings.

Forget the Ingersoll Rand,,,real bad ratings......
"The number of parasites in the USA has now eclipsed the number of productive members of society"

Capt Rick Hiott.

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PostPosted: Fri Feb 19, 2021 3:26 am
Hey hows it going ODG?
I have an IR pump and don't have any complaints about the pump.
Dennis Barnett
A&P Mechanic, FCC General radio Telephone Operator
Line Maintenance A&P Mechanic and MOC Tech specialist.

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