Air Compressor Oil

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I have a 25 year old Sears oil lubricated air compressor with a 2HP electric motor. The Owners Manual says to use 20-20W SF oil in summer and 10W oil in winter. It says do NOT use multi-viscosity oil because it "will leave carbon deposits on critical components reducing performance and compressor life". Are modern multi-weight oils ok to use? Thanks.
 
My 5 y/o CH compressor said similar things about most motor oils "except Mobil 1"

I chose to use an Amsoil compressor oil in the end as it's directly suited to purpose and one bottle will last me a very, very long time. You'll need to convert the SAE engine oil weight to the ISO compressor oil weight in order to select the right one. Or, of course, Amsoil could simply help you with that.
 
No modern multiweights still break down, shear out of grade and leave damaging deposits. What have you been using for the ppast 2 decades, seeing its 25 years old? I would think a 5w-20 oil should be safe with MUCH less VII than a 5w-30. If not use a quality SAE20 HD - if you can find one.
 
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For most compressors you have three choices:
30 non-detergent
5W30 or 10W30 full synthetic
compressor oil

Campbell Hausfeld/Rigid recommends those oils for most of their oil lubricated pumps.
 
Originally Posted By: artbuc
I have a 25 year old Sears oil lubricated air compressor with a 2HP electric motor. The Owners Manual says to use 20-20W SF oil in summer and 10W oil in winter...


Are you sure it's not older? That is a really odd spec for something that's only 25yrs old. I've seen the 20w20 spec on various equipment, but it was well over 30yrs old. I'd throw a 5w20 motor oil in there, especially if you need to start it cold.

Joel
 
Here's the thread from 2007 where I was figuring this out.

I found that Amsoil's ISO/SAE cross reference was about one grade off from everyone else's. It was determined that this was because of the properties of the syn (likely PAO) basestock they were using having a VI much better than the typical dino base for which most conversion charts are written.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=882243

If you don't want to contact someone like Amsoil and simply ask about "SAE 20W20" compressor oil you could search for a table somewhere for the median viscosity @40C of 20W20 dino and then use a table like this to map to the ISO rating.
 
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Originally Posted By: JTK
Originally Posted By: artbuc
I have a 25 year old Sears oil lubricated air compressor with a 2HP electric motor. The Owners Manual says to use 20-20W SF oil in summer and 10W oil in winter...


Are you sure it's not older? That is a really odd spec for something that's only 25yrs old. I've seen the 20w20 spec on various equipment, but it was well over 30yrs old. I'd throw a 5w20 motor oil in there, especially if you need to start it cold.

Joel


Joel, I can't remember exactly when I bought this unit but I am pretty sure it is in the 20-25 year range. For kicks & giggles, I will confirm the manufacturing date.

I did look at the oil over the W/E. It looks great. Can't remember when I changed it last but it has been years. I don't use it very much so I may still be well under the 100 hour OCI.
 
Originally Posted By: artbuc
Originally Posted By: JTK
Originally Posted By: artbuc
I have a 25 year old Sears oil lubricated air compressor with a 2HP electric motor. The Owners Manual says to use 20-20W SF oil in summer and 10W oil in winter...


Are you sure it's not older? That is a really odd spec for something that's only 25yrs old. I've seen the 20w20 spec on various equipment, but it was well over 30yrs old. I'd throw a 5w20 motor oil in there, especially if you need to start it cold.

Joel


Joel, I can't remember exactly when I bought this unit but I am pretty sure it is in the 20-25 year range. For kicks & giggles, I will confirm the manufacturing date.

I did look at the oil over the W/E. It looks great. Can't remember when I changed it last but it has been years. I don't use it very much so I may still be well under the 100 hour OCI.


My Craftsman is 22 years old (1988) and has the same oil spec as yours. I bought it about 2 years ago from a guy who had bought it used but had never ran it since he didn't have 220v hookup.

So I don't know what oil had been used in it all those years. But it was dirty and needed changed, so I called a Devilbiss (manufacturer) tech and he said it was spec'd to use the 20-20w SF, but that I could use a good syn motor oil in it. I had some 10w30 PP on hand and used that, and it's been doing fine ever since.
 
Eastexan, my Craftsman can run on 120 or 240. The wiring conversion is simple with directions right on the motor. Takes about a minute to do it.
 
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