[67stang]

Thinking about buying an air compressor. Don't know squat! How big do I need, what brands, etc. This will be for my home garage and will power tools, grinders, maybe an occasional spray gun for detail painting. Does Sears make adecent one? What air tools should I get with it?

 

[Hemikiller]

Sears makes a decent compressor. I've had their oil-less 6hp 33gal laydown unit since '94. This would be fine for your garage. TRhey run around $350-400 these days. They are very noisy, but reliable (finally broke a rod in '9

and cheap to fix ($30 worth of parts). I used mine to power the garage I rent with 3 friends, and our usage varied from air tools to painting cars. We did always intend to get a big propane tank as an auxiliary reservoir, but never got around to it. That compressor is now on backup duty, as we now have an Campbell Hausfield 6.5 hp / 60 Gallon upright cast iron series. This one is just as noisy (different kind of noise though) but seems to keep up better.It does get a workout when I'm sandblasting or grinding / sanding. My garage is piped with 3/4" iron pipe throughout.
My recommendation is this. Get the CH or IR or any other 6hp 60 gal upright as they will do anything you want them to do in a hobby environment. You can get them at Lowes, Home Depot, Napa etc. They are single stage (125 pi max) and generally oil bath cast iron compressor. If you want a step up, get a two-stage @ 6hp 60gal (175 psi or more) and cost a bit more, but your air tools will run like never before. All professional garages run at 175, as they have big compressors. The extra air will not hurt tools like impact guns, air ratchets, but can hurt any free running tools like sanders and grinders, but that is why we have air pressure regulators both on the tool and mounted permanently.

I don't reccomend getting the "package" with your compressor, as the ones I've seen generally aren't very good quality. I've got Snap-on and Mac stuff. I just bought a CH high speed air sander for my latest project, and am very happy with it. WalMart carries the CH tools at good prices. They come in a couple of grades like "Serious Duty" and "Standard Duty". For things like impact guns and air ratchets, get the Serious Duty. For stuff like sanders and drills, you could get away with their standard. They have a good warranty, so don't worry. I'd try to stay away from the mail order tools that are made in China, Taiwan etc. Never had great luck with them, no power, break easy....

This type of tool is a "get what you pay" situation.

 

[n2omike]

If all you need to do is pump up tires and run the occasional air wrench, you don't need much. A 3-5 hp 20 gallon tank (around $300) unit is plenty. If you want to paint cars, sandblast, or run sanders and grinders (without spending more time waiting than grinding) a 240V, 60+ gallon unit with a 2-stage compressor will be required. These start around $800.

The smaller 120V single stage units are available with oil-less or oil-type pumps. The oil-less ones make a high pitched, irritating sound as they run. The oil-type compressors use a seperate motor and pump connected by a belt. These generally pump larger volumes at lower speeds, and are a lot easier on the ears.

All 240V 2-stage compressors use oil-type pumps. These 240V 2-stage units put out a LOT more air than single stage units, pump up to 175psi (compared to 125) and are pretty much required for sandblasting, air sanders, and air grinders. They also seem to put out a lot less moisture.

Sears makes a 2-stage oil-less compressor that will pump up to 175psi that's pretty cheap, but it doesn't put out any more cfm than the single stage units.

Good Luck!

 

[oils65mustang]

Hemikiller pretty much said it all.
Look at the tools your using or going to use. They should have a required [email protected], e.g. a die grinder is about 4 cfm @ 90psi. Your air compressor will need to have the volume and pressure to keep up with the tools. Too small of a capacity compressor with a small tank will wear out quicker than a larger capacity compressor on a larger tank. But the smaller unit will be cheaper, initially. Also, buy a brand name from a know retailer like Sears, Home Depot, Lowes..., that's my recommendation for buying tool such as air compressors.
Also, the compressor is not the only item you need. Moisture separators, oilers, filters, etc... If you paint you need dry air, if you use a die grinder you'll need an oiler. You'll want a separate hose for painting to keep out contaminates.
To summurize, what is your appilcation? What is the capacity required to operate your tools? What other accesseries do I need?

As for tools: die grinder, sanders, non-impact wrencher. Whatever you want to do there is an air tool for the job in most cases.

p.s. All air compressor are noisy.

 

[n2omike]

Those 'air requirement' ratings are misleading. My 120V 5hp oil-type 20 gallon compressor is rated at 9.1 scfm @ 90psi. My die grinder, cutoff tool, and Ingersol Rand 90 degree grinder are all rated around 4 scfm... But, what they do NOT tell you is the duty cycle. You spend quite a bit more time waiting than grinding. My compressor won't even THINK about running those tools continuously... and you can forget about sandblasting. You'd do WAAAYYY more waiting than blasting.

A friend of mine with who has an expensive (powerful as you can get without going 3-phase) compressor is at it's limit with hard sandblasting duty.

The point is, buy MORE than what you think you'll need. If any sanding, grinding, blasting, or even painting is in the plans, invest in a 240V 2-stage pump... they ARE that much better.

Good Luck!

 

[1965FALCON]

I think everybodys pretty much said it all. I also have a craftsman 6hp 60 gal upright oil-free (noisy as hell). Does a good job with tools - for paint spraying with an HVLP it's pretty much maxed out (works though). The CFM rating given on compressors is at the compressor itself, you need to also account for the loss in your hoses etc. 50 ft of 3/8 hose will eat 20 psi. Like mentioned before, run 3/4 iron around your garage with an oil/water seperator at the end. You'll lose less pressure that way, and be able to use a shorter hose.

 

[KB]

The only thing I would add is to use heavy PVC at 1 inch or more for plumbing the shop. You just have to have about 4 foot of iron from the compressor to absorb heat and vibration. The PVC is rated at 300 and will never add rust to the system. I have been running mine for years this way. Drain the air tank often. also put in drains on the lines and angle them to the drains.

 

[68StangJurls]

I would prefer copper to PVC but it does cost alot more. If you must use PVC make sure you only use threaded fittings and absolutely not slip/glue fittings.

 

[n2omike]

Schedule 40 PVC in fine, as long as it doesn't get hit hard by anything heavy.

The strongest and easiest way to plump a garage is with galvanized steel water pipe. It just screws together. Rust isn't a problem, and it's pretty cheap too.

Good info about using the larger sizes.

Good Luck!

 

[Matt]

If your going to get a compressor, get a good sized cast iron one, it will last a lifetime if the tank is drained regularly, and can be rebuilt if and when the rings in the compressor go bad. I bought a CH 7hp quad compressor for right around 1k. I wouldn't have gone with anything any smaller.

http://www.geocities.com/parthos.geo/trans/compressor.jpg

 

[67stang]

Durn! Thanks, guys! I are now a compressor expurt!!

 

[Just Strokin]

I just replaced my air compressor and I kick myself in the butt till now for not buying the 2 stage ac the first time.....I got mine at Sam's club and was $770 (i think) plus tax.

It now keeps up with the die grinder, cut off tool and the sand blaster.

Wouldn't have a single stage again...

Oh yea, Make sure the compressor comes with oil or if you need to buy some get the compressor oil before you bring the compressor home....and you don't need to ask me why I say this....