Air Compressors?


wonword
03-16-2005, 05:25 PM
Ok here is the situation. I am going to paint my car and I need a compressor for running all kinds of airtools, including sanders, grinders, impact wrenches, spray guns . . . I need to know what the minimum number of gallons that will support all this stuff(estimate with a 5hp motor). Checker's has a 22 gallon 5 hp compressor for 150 bucks, is that big enough?
Thanks,
John

mike@af
03-16-2005, 06:52 PM
I've got a 4 Gallon, and two 21 Gallons. The 21 Gallons run fairly constantly when Im on the grinders and sanders. They are 9cfm at 90 PSI. The 21 Gallon works, but after awhile it gets annoying. I'd prefer a 60-80 Gallon. The 21 Gallons are like $350, the 60-80s are like $400-$500. So I would have spent the extra cash if I wasnt given a 21, and if I had the space.

MagicRat
03-16-2005, 09:12 PM
What kind of voltage does the 5 hp use?
I have a 5 hp 110 volt compressor with a 20 gallon tank, and it is marginal for keeping up with any high flow air tool. Also it is very sensitive to poor electrical wiring. You need to be close to your electrical panel and use fat wiring. It simply will not start the motor if one uses a regular extension cord or standard household wiring, unless the circuit os bery short.
For many years I had a 2 hp 220 volt 2 cyl industrial compressor on a 60 gallon tank. It beat my 5 hp compressor hands down, even though it had less hp. The 220 volt makes a big difference.
The best compressor for high demand is a gasoline powered one. I have a 2 cyl compressor powered by a 5.5 hp Honda. It is portable and more powerful than any compressor short of my old 550 volt three-phase compressor.
My gasoline compressor is so good, I have not bothered with using my electric unit in 2 years .

wonword
03-17-2005, 12:51 PM
Hey Guys Thanks for the Info,
Umm. . . im not sure what kind of voltage it uses. But it looks like I should save up a little more for the 60 gallon 7hp that they sell at Menard's. I just want to be able to sand, grind and spray constantly without having to wait for the tank to refill. Thanks for the info though.
John

drew300
09-26-2006, 04:02 PM
I get confused by the hp ratings on these.
With 110 Volts, 1.5 hp from an induction motor is a maximum you get. These high ratings, like a 5 hp compressor on 110 V must used the stored air to get 5 hp, for a short time. that's why your 2hp motor, 220 V industrial unit beats a 5 hp.
I knew a guy who used a smallish compressor, but filled 2- 40 gal hot water tanks with 90 psi before he started into painting a car. (A water tank in our area is rated at 150 psi.) He had lots of air for the job.

Schurkey
05-05-2019, 06:20 PM
There is no such thing as a "5-horsepower, 110 volt" air compressor. It is not possible with ordinary house or small-business wiring.

As said, a standard 110--120 volt circuit can support about two horsepower. Maybe less. There's mathematical formulas for converting electric power into horsepower.

Lots of air compressor manufacturers got into trouble by advertising crazy horsepower specs. Same as shop vac manufacturers who claimed "6 horsepower" motors that were the size of a small grapefruit.

You can buy a million different brands of small air compressors that CLAIM to be able to power "real" air tools. Most of them are flat-out lying, because they will not keep up with the air demands of ordinary air tools. You'll have to stop and let the compressor catch-up.

You want an air compressor to use with automotive air tools? Real compressors START at 5 horsepower, 240 volts, and 60 gallon tanks. I had one of those. Poor thing ran continuously when I was using my die-grinder, but put out enough pressure to be useful. After a few years, I moved up to 5 horsepower, 240 volts, TWO STAGE, 80 gallon tank. That guy runs any one air tool I own, as long as I want to run it. If I wanted to run two tools at once...it would probably not be big enough.

For fukk sakes, do NOT buy an "oilless" or "oil-free" compressor. They'll make you barking insane from all the noise they make. The ONLY good thing about them is that during their short and noisy life-span, they don't put any oil into the air that can contaminate the paint you're spraying.

Stealthee
05-05-2019, 09:03 PM
You realize you're replying to a 13 year old thread right?

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