How to pick an Air Compressor? - Page 2

62406 · #21 (**permalink**) 11-19-2002, 07:58 PM

I second that Ernie!
More info than 20 magazine articles. Although they help out when the supply is low on the wall. Is that like bein multiskilled?

LOL.
ALEX

A Snake · #22 (**permalink**) 11-19-2002, 11:59 PM

Really good points here!

I would add that ALL air tools require lubrication. That being the case, it is imperative to keep the air dry.

Drain the tank before each use AND blow out the air line using an ordinary clean-up nozzle. Blow air through the line until you don't see any vapor.

I've been both an industrial and home user of compressors for over 30 years. All the way from 250hp screw type down to itty bitty 1.5hp.

I've tried a wide variety at home and found that you really can't get too much air.

I've had the parts store and department store varieties and have found that ALL of them are full of hooie on what the'll do. The big trick with small compressors is to claim a hp rating when it is not real. What they're doing is overrevving the compressor to get the supposedly higher hp flows.

Two things are wrong with this besides misleading advertising. 1. You won't get the performance and 2. The unit WILL and I mean WILL wear out quickly.

To avoid all of the confusion, buy your compressor from a company whose only business is compressors. Further, stay completely away from the small 110V units. Even the average guy will have it spitting a rod in a fairly short time.

Go with a 220V 2 stage at least 5hp w/large tank. (80gal).

Now to my choice. I highly recommend Quincey compressors. I've never been let down either in industrial usage or home usage. They are well backed by the factory and the compressor dealer you buy from will be your service and repair source. Very valuable if warranty matters come up or, you need a new filter, lubricants etc.

Last note: Put an inline hour meter on the unit and change oil by recommended hours of run time. (goes between the switch and the motor and the dealer can put it on for you.)

Dessicant type air dryers are ok but watch that you have the unit sized properly or the dessicant will saturate and be of no use. Refrigerant type are excellent, but spendy and not really necessary unless you're in a really cold climate. (yes compressed air is cold and will freeze things up if there's water in it.) Do put in a water trap ahead of the dessicant unit and drain it frequently. Down line from the dryer, you can install a lubrication unit which will keep all of your tools properly oiled. Obviously if you're painting, you'll need to put a tee in the line ahead of the lubricator with a quick connect outlet for your paint gun line. On the down line side of the lubricator, terminate the line with a quick disconnect.

While you're at it, make sure that all of your fittings match. It's no fun to constantly change hose ends.

Some thoughts. Hope they help.

Al

Jack21 · #23 (**permalink**) 11-20-2002, 05:33 PM

Thanks "A Snake" for your practical insight. Like everything else we do around here, it's never as easy as it looks. And, it's the little nit-noid details that make the difference between doing it right, and screwing it up.

It's the practical experience you 30 and 40 year guys bring to this forum that have been there and done that that help the newbies get it right the first time.

Cobranut · #24 (**permalink**) 11-20-2002, 08:54 PM

Watch the HP ratings, they are often fictional.

I have an older Black Max 5HP 2-stage on an 80gal tank, which draws 22amps at 220v.
When I built a new shop, I moved the big guy there and bought a new Campbell Hausfeld 60 gal for the garage. It is rated at 6.5HP, but only draws 15amps at 220v. Smells fishy to me, that is actually about a 3 or 4HP motor. The old one will pump the 80gal tank from 0 to 175psi faster than the new one will get the smaller tank to 120psi.

As far as air lines, put a filter/regulator at the tank outlet, and slope the lines down as you go away from the tank. Put ball valves vented thru the wall at the end of each line to blow out any moisture, and run all your outlets off tees running up from the main line. Blow out the lines every few days of use, and the tank drain each day. I've never had a drop of moisture get to a tool or paint gun with this setup.

Later,

427 S/O · #25 (**permalink**) 11-21-2002, 01:12 AM

You probably overlooked this, I did, Dry Cleaners all have large air compressors.
After driving through the one I use many times I finally noticed he had three out back with only one working, on my next
trip I went inside and ask the owner about the other two, he said they were broken!, I picked them up for 400 bucks.
Got my trailer, loaded them up and took them to a local air compressor shop where I made a deal, I would give them one of the compressors if they would rebuild the other, done deal, they were both good quality cast iron, 220V, twin cylinder.
10 years later and still going strong.

Howard Bosworth · #26 (**permalink**) 11-21-2002, 08:27 AM

My craftsman is about 10 yrs old still runs small sprayer and nailer etc. but if you look for gas stations going out or some big tool and auto auction places you can find a big one that will run all the air tools that you eventually will collect.
Gets pretty loud when tools and a small compressor are running constantly in the garage
Howard

DAVID GAGNARD · #27 (**permalink**) 11-21-2002, 01:34 PM

Having worked in a body shop for 14 years and been around them all my life,my advise is buy the biggest you can afford,regardless of what you plan do to with it.....

Dual stage,220v with the biggest tank you can find is the best.....One shop I go to has one large compressor on a tank I'd guess to be about 100 gallons and then another tank I'd guess to be at least 250 gallons,he runs a rather large shop on this one compressor...You not only need pressure,but you need volume.....Stay away from the oiless ones,they generally do not last...

The shop I worked in had one Gilbarco dual stage with a 7.5 hp motor and 80 gallon tank. We were 6 employees and that compressor is still running today and was bought new in 1974......We would change the oil and air filter once a year whether it needed it or not and that is all the matinence we did on it...The compressor has worn out at least 6 or 7 electric motors to date,runs five days a week,50 weeks a year....

When you pipe your shop,I'd also recommend 1.5in diameter hard lines and put a water trap on every line....

One day went I went to pick up a new electric motor for the shop compressor,I noticed an air compressor apart in a box sitting on an 80 gallon tank covered with dust and junk,been sitting there for 5 years. Owner bought it and decided to overhaul it first and never got around to doing it once he took it apart. I bought the whole thing for 150 bucks with no motor.. 55 bucks for rings and gaskets and another 150 for a heavy duty 5hp electric motor,been running for 15 years now at my house and it will outlive me!!!!!!!! It is a dual stage American Kellogg and will run any and everything I can hook to it...Piped my shop with 1.5in pipe and I have four outlets around the shop with water traps on each one...No regrets at all.....I have been offered a thousand bucks for it several times,someday when I'm gone my daughter or wife will probably sell it for 100 bucks just to get rid of it though....

Check with your local body and mechanic shops in the area as they sometimes have spares or when one brakes they do ot have time to repair it,so they just buy a new one,they can not afford the down time....Good deals are out there..

Over the years,I have picked of five for little or nothing,cleaned them up,painted them and resold them for a very good profit....Everything from the little Sears type portables to shop compressors the size of mine,never had one for sale more than a few days before I got my asking price....

David

Bob Parmenter · #28 (**permalink**) 11-27-2002, 02:52 PM

Ron,

Check www.eatoncompressor.com . Helpfull folks that are very service oriented and will share some interesting comparison info with you.

downloder · #29 (**permalink**) 05-26-2004, 05:11 PM

Hello all,
Was searching for some info on Speedaire compressors and ran accross this thread in the search, so thot I'd drop a piece of info that maybe can be passed on. This site has a good article on "How to choose ..."
This is a neat site, tons of info, and even tho I do not own a Cobra, I am impressed.
At present I have a 5hp Cambell directdrive w/ 20 gal tank. I does ok for most hand tools, but for a longboard, a spraygun, and a DA it works REAL hard. That's why I need to get this Speedaire going .
Chris

Sorry, forgot to put in the link...

http://www.kmstools.com/pages/compressguide/

ToyCollector · #30 (**permalink**) 05-26-2004, 05:55 PM

CW, what did you ever go with?