Air compressor oil

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I just replaced my broken oil-less air compressor with a piston type that uses oil in the crankcase. The oil specified is "SAE 30 weight non-detergent air compressor oil" and a 15 oz. bottle was supplied, which I used. How critical is it that I use this same type of oil in the future? Would any harm be done if at some point I topped it up with, say, 10W30 motor oil if the level was low and I didn't have the specified oil handy?
 
Everything I have read is not to use engine oil. So I bought semi synt air compressor oil at Lowe's(Lowes name on the bottle) and the compressor seems to be fine with it.
 
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Syn motor oil will work fine. I worked for a company that used Delo400, straight 30 wt in the service van compressors and the compressors were moved from the old vans to the new vans. I worked there 17 years.
 
I have no idea but i was told by Quincy not to use motor oil of any kind in the unit.I mix Amsoil 20w and 40w compressor oil to get the recommended 30w because they do not sell 30w in quarts. Redline offers 30w compressor oil in qts and is also recommended.
Any left over gets used in the automatic air tool oiler,it works great.
 
Motor oils contain organometalic detergents that may contribute to valve deposits, and dispersants that may emulsify water in the oil. Best to stay with a non detergent 30 wt. oil designed for air compressors.

Tom NJ
 
I know that Tom but the company I worked fo used motor oil in the recip compressors and they had many vans with compressors.
 
After posting here posed the same question on the compressor (Trades Pro) manufacturer's site because I had seen their guru likes synthetic oil for low temperatures and the only synthetic I have is motor oil. He answered that I can use any good grade of oil and highly recommends synthetic. So, unless I come across some synthetic compressor oil at the local auto parts store, I'll just use Mobil 1 or Syntec 0W30 when it comes time to change the oil.
 
I have a similar issue. My IR compressor requires SAE40 or ISO 100 compressor oil which can't be found locally.

M1 10W-40 is almost the same viscosity as ISO 100 at 40 degrees C. Does M1 10W-40 contain much ash or other [censored] that could clog the compressors valves.

I could special order some Amsoil ISO 100 compressor oil but hate to pay the freight if M1 10W-40 is a good choice.
 
My old compressor is a old cast iron twin cylinder belt drive - I call it my Jed Clampit compressor. It looks real bad, abused, junk yard material - but runs like a dream.
Man - maybe I should check the oil. Been several years since I checked it. Must be near out. I never think about the compressor, just use air when needed and it's always there.
A good winter project to put on my list - get a jug of compressor oil and give it a go.
 
this is interesting I found this thread towards the top w/o a search; I have 2 compressors at present; both older "EMGLO" brand; a 1977 vintage (they still sell this very unit today under both DeWalt and the "Jenny" name) wheelbarrow type w/a 5HP Briggs engine; only difference? New versions have a Honda engine.... YUKK!
my other EMGLO is a 1987 version, 5HP 80 gallon upright 2 stage 4 cyl pump;
I am noticing something lately, that I remember from my days in the tire/alignment shop, and with other piston compressors I have dealt with;
In my water trap as well as out of the tank when I drain them, I get a white milky, sludgey mess; I recently got the gas powered machine; IDK the history though it was supposed to be "1-owner"; my 80 gallon upright I have had now about 8 years, bought used from a former body shop owner; but never really noticed this til recently (temps were still warm) I admit I don't drain my tank as often as I should, but more often than many I know w/ compressors, who tell me "Yeah I ought to one day, huh"?

Anyway back to the whitish sludgey slimy mess I get out of them; What is this caused by??? I try to stay with a regular 30W straight weight dino oil, same stuff I run in my air cooled mowers etc; but have been known to occasionally top off with what ever I have sitting around and is a less than full bottle;
everything else I have, I run 10-W-40 Valvoline year round; I have no OHC engined vehicles; all Dodge 318s 360s and Jeep 4.0s;
I have never bought the regular "compressor oil", as I always thought that the label was a batch of [censored] to be able to charge more; like buying Briggs and Stratton "small engine oil"... double-plus what even premium oils cost and they only give you like 2/3 of a quart.... I have never been a synthetic fan (synthetic means "artificial"/"fake" right? and it is extremely costly vs a conventional) and the brand, weight, type of oil I have used, has not mattered; I never saw that sludge [censored] from my 80 gallon unit til a few months ago; I am a homeowner and use this for my personal use not business, where it would run non stop;
as a former 18 yr professional alignment tech, I still get calls from former customers asking me to fix their stuff here, as side jobs; I have a glass bead cabinet which I use fairly often; the 80 gallon has never failed to keep up with anything I have thrown its way; incl running a 100 lb pressure pot blaster in resto of a projecr car or most recently a home built trailer I blasted;
I often get water accumulation and I have noticed it very dependent on weather; I have several water traps; so I can keep an eye on that; but regardless how hard and heavy I have used my compressor (or not) or what oil I put into it, the sludge thing just started;
the portable I just got last week, and have run it a few times, "de bugging" it and catching up on maintenance and noticed it right away from that one;via the clear bowl on the water trap (though it is winter in Chicago) I changed oil in it upon the 1st time I used it (put regular 30W in it) growing up my parents had a 2HP Campbell Hausefield, new in about 1976, (I was with Dad when he got it, I was about 9 or 10) still runs fine, and doesn't do this; and oil changes... WHAT oil changes on that unit; I ran the snot out of it in my '80s teen years; and it still don't sludge up.
Neither my parents' or my 80 gallon use much oil at all;(a little but to be expected due to the nature of an air cooled, air compressor) the gas powered one I have not had long enough yet to tell whether it will (or won't) be an oil user; I remember one we had at the tire shop that "drank" oil; but it was very old and TIRED. it would not build the pressure it once did, took too long to build what it did do, and finally got replaced.
I don't mind a little oily residue as I figure it can only help to protect the innards of the tank; but what does bother me is the sudden noticeable increase in the amount of it;
I do not believe my compressor is wore out, it still builds pressure as readily as ever, and like doing a compression test on an engine, it cannot put more PSI in the tank than it can build within the cylinder.... but would this be related to choice of oil in the crank case? what IS "compressor oil"?
I choose to oil my air tools as I use them and not off of a central inline oiler as my glass bead cabinet would not like oil,and I do occasionally use my compressor to paint with... in fact taht was exactly the reason I bought the 5HP gas powered one to take to a buddy's farm where I am doing some painting too far away from both an outlet and the breaker box; I tried a 110V Portable and was spending too much time going over to reset the breaker; compressors don't like 125' of extension cord off a 15A breaker (I tried 2 different units out there) and the owner of the property where I am doing this painting at, asked me about painting that barn come Spring once the weather improves; so having available air that's not tied to an insufficient electrical panel will help tremendously; but I want to eliminate this sludgey [censored] from the line so as not to ruin the paint job... IS the solution as easy as using a different oil in the crankcase???
 
The whitish sludgey slimy mess you describe sounds like an emulsion, which can form by agitating water with dispersants or detergents, such as those used in motor oils.

Oils formulated for air compressors generally contain only anti-oxidants, anti-rust/corrosion, anti-foam, and sometimes anti-wear additives, intentionally leaving out detergents and dispersants for this reason. A cheaper alternative would be a non-detergent 30 weight motor oil meeting API SB.

Tom NJ
 
NAPA carries Valvoline ND 30 weight API SB. It's in a white bottle with a picture of an air compressor on the front.

Ed
 
White sludge is water emulsion in the oil. Try the [censored] that says compressor oil on the bottle... they really do make it for a reason.
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Edit: Looks like Tom already got to this. And he is right about the different additive package in compressor oil. But may have forgot that some contain demulsifier also.
 
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Sorry to bring up an old thread that has been answered to some extent, some clarification may assist.

A rule of thumb (not a "Golden Rule"), is that if you have recirculated and filtered lubrication system, detergent oil is required. The detergents keep particles in suspension for the filter to remove. Splash/closed lubrication requires non-detergent oil so the the particles settle as sludge in the bottom of the sump. As stated, compressor oil contains additives that prevent foaming, corrosion, etc without the detergents/dispersants that would allow suspended particles to wear out the moving components. Topping up with motor oil may get you out of a bind, however, you should change the oil as soon as you can.
 
Have a compressor from pepboys had 30wt oil in it, it leaked out chaged it to rp 20w50 ran fine. Just changed it to delo 400 15w40 seem to work even better with the delo.
 
I bought a Bosch 3 gal compressor and they weren't of much help.

I emailed Mobil and they suggested Mobil Rarus 427 compressor oil for the reasons mentioned. Deposits and cold start issues are avoided. Problem is no supply place around here sells it.

DeWalt sells a synthetic compressor oil that has all the properties listed, so I may go with that.
 
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