Air compressor oil question

[Ruperto Mendiones]

I just acquired an Ingersoll-Rand 3 hp piston air compressor. IR $ynthetic oil is recommended. Are there any commonly available alternatives on the market? What characteristics of the oil are needed [viscosity, additives etc...]? What happens to the oil that necessitates changing it?

[Jacob Reverb]

What characteristics of the oil are needed [viscosity, additives etc...]?

In my experience most compressors call for non-detergent oil. Mine wants 30W in summer and 20W in winter.

I think Mobil makes a special compressor oil (Rarus?) which is good for high-use compressors where there's a lot of heat...

See:

http://www.mobil.com/USA-English/Lub...Rarus_400.aspx

[Bill Geibe]

I have a 5HP IR compressor in my garage. In winter, with conventional oil, the oil would thicken and the compressor would blow the breaker when it started. I changed to IR synthetic and that problem has gone away. I got the oil at Tractor Supply.

I don't think changing compressor oil is all that critical. In a gasoline engine, there are many combustion byproducts that blow past the piston rings and contaminate the oil. In an air compressor that doesn't happen beyond maybe some carbon. I think I've changed the oil in my compressor once or twice in about 20 years. My compressor has a sight plug and if the oil was dirty I could see it.

As far as viscosity is concerned, I don't think the IR synthetic lists one. The Campbell Hausfield conventional oil is listed as 10w30. Use whatever your compressor recommends, unless you are running it in extreme heat or cold.

I would be willing to bet that if you put a good automotive synthetic in a compressor it would run forever but I haven't tried that. I don't think an air compressor puts nearly as much stress on oil as a gas or diesel engine does. Mobil says "No" though. http://www.mobiloil.com/USA-English/...mpressors.aspx

Here's another interesting thread: http://www.bobistheoilguy.com/forums...Number=2282237

Bill

[Jim Andrew]

Amsoil sells a synthetic compressor oil.

[Thomas Hotchkin]

Ruperto
I have a new Campbell Hausfeld 3 HP compressor, they recommend Mobil 1 10-30.

[johnny means]

I've been putting whatever I last put in my car for years. No problems, I don't think its all that critical. Though, if I was running it hard for eight hours a day, I might put a little more thought into it. I think the key is to watch your levels. The oil will gradually atomize and be expelled with the air. If you don't have one get a good filter to keep the oil out of your airlines.

[Rick Fisher]

I have always believed that non - detergent oil was better for compressors..

[Ken Fitzgerald]

My compressor owners manual recommends compressor oil. I buy compressor oil at my local Ace Hardware store.

[Biff Johnson]

I have an IR compressor as well. Grainger's sells a prepackaged service kit with air filter and synthetic oil. I don't remember the exact price but it was reasonable. I've purchased it twice since owning the compressor.

[Mike Seals]

Oil in a compressor takes on a different role than that of oil in a combustion engine. The oil in your car has a lot of extra chemicals in it to combat moisture and the trash from the combustion cycle. And most of the chemicals are activated by the presence of their target and heat. Our compressors do not generate the heat our automotive motors do and the auotmotive oils will not react the same.


Now on the reality side, all that extra stuff they add in motor oil can have some side effects. You don't want it in your eyes or for prolong periods, on your skin. Millions of dead white rats can attest to that. And if any ones used a home piston style compressor for prolong periods, you know some of that oil escapes past the pistons. So they just say don't use detergent oils....

[Jacob Reverb]

I think one reason they spec non-detergent oils is because detergent oils keep the dirt, metal, impurities, etc., in suspension so that they can be filtered out. But unlike cars, most air compressors don't have oil filters, so it's better if the metal, dirt, etc., settle out. I also suspect they want any water in the oil to settle out in an air compressor, rather than become an emulsion with the oil and detergent (think: milkshake).

[Rick Lizek]

I've been putting whatever I last put in my car for years. No problems, I don't think its all that critical. Though, if I was running it hard for eight hours a day, I might put a little more thought into it. I think the key is to watch your levels. The oil will gradually atomize and be expelled with the air. If you don't have one get a good filter to keep the oil out of your airlines.

The detergent will destroy o-rings and seals in in your air tools. Use non-detergent oil

[Ruperto Mendiones]

Quincy compressors puts out an extensive discussion of lubricant requirements: http://www.quincycompressor.com/imag...20002_0811.pdf

[hank dekeyser]

Been using non-detergent straight weight 20 o r30 in my relic forever. I think it came over in the Mayflower (1-1/2 hp motor the size of 5 gallon pail) -nice-

Compressor oils will accumulate moisture over time (in my experience) the moisture emulsifies and becomes one with the oil - I change mine out about every 6-9 months (that reminds me, it's been awhile)

Newer compressors might have different requirements ? (alloys, different grade of materials, etc) better to err on the safe side IMHO