Whats special about compressor oil?

[3v0]

The subject is the compressor oil we use in our 120psi, reed valve, home compressors. Not talking about synthetic oil.

I have been looking around and have found nothing to show where the oil bottled specifically for this use is anything more than common non detergent oil.

Spent a few minutes looking at compressor oil additive packages The ones I found are for high temperature industrial compressor. Not the same.

3v0

 

[dnschmidt]

Who cares, go to Harbor Freight and buy a $7.49 quart bottle of compressor oil. Use a 20% off coupon and the price reduces to $6.00. A quart will last you decades. What's the point of launching an expedition?

 

[MacMcMacmac]

The subject is the compressor oil we use in our 120psi, reed valve, home compressors. Not talking about synthetic oil.

I have been looking around and have found nothing to show where the oil bottled specifically for this use is anything more than common non detergent oil.

Spent a few minutes looking at compressor oil additive packages The ones I found are for high temperature industrial compressor. Not the same.

3v0

Probably not a whole lot of difference on lightly used machines. Once they wear and pass oil, or if used very hard, any detergent or multi-grade engine oil residue present on the valves will burn and coke the valves with hard glassy deposits, leading to poor performance. Poorly operating valves accelerate coking due to the excessive operating temperature created by hot compressed air leaking back into the cylinders and being re-compressed. I have used ball peen hammers and brass drifts to extricate valves out of a Quincy that has been run on 15w40 out in the oilfield. They looked like sea urchins. A similar scenario using proper low ash compressor oil will produce a valve with a light dusty soot covering and remain usable valves right up to overhaul time, requiring minimal clean up and repair. It's well worth the money if you use your machines hard or if they are worn. ALL recips with a crankcase vent scavenge line intake some oil from the crankcase blow by. It lightly lubricates the valves during normal operation.

 

[bob15]

I care. Pour point is a big one that makes a difference. RP gelled up on me and the compressor didn't turn over during that cold spell. When it somewhat warmed up, I dumped the oil, added just under 3 quarts of compressor oil from a different company and the issue went away.

Additive packages for compressor oils are what makes it special.

https://www.ingersollrand.com/en-eu/news/compressor-blog/what-type-of-oil-should-i-put-in-my-compressor-.html

https://www.efficientplantmag.com/2009/05/proper-selection-a-monitoring-of-lubricants-for-compressors/

https://www.mobil.com/en-CA/industrial/pds/io-ca-compressor-oil

 

[Sportsman762]

We always used 30W non detergent in the larger air compressors. They fire up at -20F just fine if you plug the engine in first. However these are engine driven units. I know the pressure washer also uses 30W non detergent. I believe the non detergent part is special for compressor oil. however check your owners manual.

 

[xjfish]

I currently have ATF in mine, high detergent I'm sure. It has worked seemingly well for over a year. I decided to use ATF for cold use reasons, and i had some on hand... I no longer need to use this compressor at -20* Want to switch to something heavier.

Is the HF stuff good enough quality? I think my owners manual specifies SAE 20w and 10w for below freezing use.

 

[WittHay]

Is the HF stuff good enough quality? I think my owners manual specifies SAE 20w and 10w for below freezing use.

Well if you are talking about jack stands probably not. The trouble with dollar stores like HF is there are 2 sku's for even a simple thing like compressor oil with zero technical or manufacturer information.

Princess Auto and the local tool/industrial type store sell Rolair 30W compressor oil. According to the MSDS sheet it is manufactured by US Lubricants and is a AW100 hydraulic oil and labelled as 30W non detergent oil on the container.

I dont think it is too much different than regular 30W non detergent. They also carry Rolair and IR synthetic blends

 

[3v0]

If its just non detergent oil you can buy a 2 gallon jug for less than $25. True Value Hardware and Rural King are two that have it.

I need this stuff for my total loss plain bearing (read this as old) metal lathes. Thinking it would be great if I could use it in compressors too.

 

[Tallpilot]

I use this stuff. Compressor oil is pretty cheap but I don't quite trust Harbor Freight even though it probably is better than engine oil or ATF.
https://www.amazon.com/dp/B01LZBNQ9W/?tag=atomicindus08-20

 

[EZ_Garage]

IIRC, I think my 80 gallon 2-stage compressor actually calls for 30wt. synthetic motor oil in the manual.

 

[Brand X]

I use this stuff. Compressor oil is pretty cheap but I don't quite trust Harbor Freight even though it probably is better than engine oil or ATF.
https://www.amazon.com/dp/B01LZBNQ9W/?tag=atomicindus08-20

That is pretty good oil for smaller amounts, and works well in small compressors with cold start issues.. I've been running stuff from Pacific air stuff in my Curtis for over 20 years.. Zero carbon build up when using quality synthetic oil. Disk valves it's pretty important.. The stuff goes a long time between oil changes, and makes the most $$$$ sense long term.

https://www.pacificaircompressors.c...-full-synthetic-reciprocating-compressor-oil/

 

[engineer2]

Non-detergent oil is for compressors or engines that don't have an oil pump and filter. Particulates can settle to the bottom of the crankcase until the next oil change.

Detergent oil keeps particulates in suspension to they can be pumped thru and be trapped by an oil filter.

 

[3v0]

Non-detergent oil is for compressors or engines that don't have an oil pump and filter. Particulates can settle to the bottom of the crankcase until the next oil change.

Detergent oil keeps particulates in suspension to they can be pumped thru and be trapped by an oil filter.

I get that. But I have been wondering why air compressor oil goes for $6 or $12 a quart when non detergent oil can be had for $2.50 a quart. The labels say its specially formulated for compressors. I don't see where its special. Sort of like saying water is a special flavor of koolaid.

 

[3v0]

I use this stuff. Compressor oil is pretty cheap but I don't quite trust Harbor Freight even though it probably is better than engine oil or ATF.
https://www.amazon.com/dp/B01LZBNQ9W/?tag=atomicindus08-20

Saw a YouTube video recently that claimed companies were printing unearned API specifications on oil. Dollar General was mentioned.

 

[engineer2]

This article is a bit vague, but basically the additive packages are different so follow what the compressor manufacturer says. Maybe we have a tribologist on board who can explain in more detail.

https://www.tribology-abc.com/abc/oil.htm

 

[3v0]

This article is a bit vague, but basically the additive packages are different so follow what the compressor manufacturer says. Maybe we have a tribologist on board who can explain in more detail.

https://www.tribology-abc.com/abc/oil.htm

From that page. " In reciprocating compressors lubrication include the crankshaft, bearings, connector rod, wrist pins, pistons, piston rings, cylinders and valves."

Just like a small 4 cycle engine which have been using non detergent oils. Compressor use is even less demanding due to the lack of combustion. The chart lumps all compressor together so its useless or close. I don't see where there is any pertinent information here.

Maybe we can get project farm to test some of this stuff. Send it off to the lab and find out.

 

[reader2580]

I always assumed compressor oil is more expensive (at least in retail quart bottles) because so little of it is sold compared to motor oil. I don't change my compressor oil often enough to worry about looking for an alternative oil to save a few bucks a quart.

It is sorta like toilet paper for RVs. It is more expensive so a lot of people say to just use regular TP instead. I use about eight rolls of TP a year in my RV so I buy the special RV TP for a few extra bucks a year. I don't need to have sewage issues in my RV.

 

[MacMcMacmac]

Compressor oil is vitally important in older large recips that actually inject oil into the cylinders via a lubricator. Improper oil in that application would be very bad news. We have 2, 1250hp Worthington BDC compressors at work and they are double acting through a cross head, so there is no splash lube available from the crankcase. Each cylinder has oil directly injected into the cylinders. Yes, it's messy.

 

[Jagmandave]

Ingersoll lists a synthetic oil for use in small recip compressors smaller than their T-30, which uses a different oil.

I would think the synthetic is the way to go if your compressor lives out in the garage like mine does, where it can get down into the high thirties inside in winter.

My new 2 stage 80 gal compressor came with synthetic in it.......

 

[Tallpilot]

The thing I don’t understand is the complaining. If it’s for a work tool it’s a deductible expense. If it’s for home use, you are buying a quart every year or two. It’s about the price of a 12 pack. Just buy the right stuff.

 

[Al Borland]

30 weight in mine is probably 40 years old.
Get something good and as the Snap-Off guys say "Buy once, Cry once"

 

[3v0]

The thing I don’t understand is the complaining. If it’s for a work tool it’s a deductible expense. If it’s for home use, you are buying a quart every year or two. It’s about the price of a 12 pack. Just buy the right stuff.

If you not interested don't read the thread.

As people are saying we use so little why does it matter. It curiosity. I have done some looking on the web and have not seen anything conclusive.

I want to know if there is a significant difference between a $5 quart of non detergent oil and the $15 quart of compressor oil. Maybe spending 3 times as much makes us feel like we are doing the right thing while we are being fleeced.

 

[mille755]

Mobil rarus 427 is pretty much clear as water.
ND30 from Walmart is the typical caramel yellow of motor oil. Also you will probably be better off with 20w for intermittent use. FYI rarus 427 is 30w/ iso100.

 

[sberry]

As far as we know the synthetic is better under some extreme conditions. I has seen Dino 30 or 40 yrs old, a couple more, no one ever thought to change it but some see limited use. I think a couple of the makers rated 50% duty on Dino and 100 on synth. If it's any better or longer life I am ok with the price difference. I hate changing oil.

 

[vanapplebomb]

I get that. But I have been wondering why air compressor oil goes for $6 or $12 a quart when non detergent oil can be had for $2.50 a quart. The labels say its specially formulated for compressors. I don't see where its special. Sort of like saying water is a special flavor of koolaid.

It’s economy of scale. They make huge amounts of universal oils like Valvoline 5W20 every minute, so it is cheap to produce per unit. Compressor oil is an application specific oil, like Amsoil Zrod or Brad Penn racing oils, which are blended in smaller batches resulting in higher costs per unit produced.

Compressor oil differs from motor oil in the additives. Motor oils have a ton of things added to the oil to deal with blow-by fuel vapor that condenses in the oil, combustion byproducts, extream pressure lubricants like zinc and phosphorus for the valve train, anti-acids, etc. Although useful in motors, they can be detrimental in compressor pumps, building up deposits over time. When they form around the reed or disk valves, the pump looses efficiency because the valves fail to seal well.

 

[Hytekrednek]

I use the Ing. Rand all weather. Was the best available locally. I used royal purple before that. Both seem fine. I trust the IR oil more.

 

[3v0]

It’s economy of scale. They make huge amounts of universal oils like Valvoline 5W20 every minute, so it is cheap to produce per unit. Compressor oil is an application specific oil, like Amsoil Zrod or Brad Penn racing oils, which are blended in smaller batches resulting in higher costs per unit produced.

Compressor oil differs from motor oil in the additives. Motor oils have a ton of things added to the oil to deal with blow-by fuel vapor that condenses in the oil, combustion byproducts, extream pressure lubricants like zinc and phosphorus for the valve train, anti-acids, etc. Although useful in motors, they can be detrimental in compressor pumps, building up deposits over time. When they form around the reed or disk valves, the pump looses efficiency because the valves fail to seal well.

Straight weight non detergent no additive oil is inexpensive to make and still sells enough that it can be marketed at a reasonable cost. But is it really a suitable oil for our reciprocating reed valve compressors?

I don't know because I have not seen anything that looks like an additive package for our compressors. Yes they exist for rotary compressors and can be used with our compressors but are these additives beneficial.

I am going to see if I can get someone from the lubrication industry to talk with me.

Thanks to everyone who commented.

 

[WittHay]

Gave some more thought to this thread and I think the difference between air compressor oil and non detergent oil is the industrial air comp oil has a higher operating temperature limit and is available in different ISO grades. Two-stage compressors run hot and rotary screw ones need a lighter grade.

Esso/Mobil air compressor oil like Rarus 427 is a clear hydraulic oil designed for higher heat and different operating conditions than regular high pressure hydraulic oil. If you buy clear compressor oil like Rolair or other brands most likely its industrial ISO100 hydraulic oil

Esso now Exxon/Mobil used to have some called 30W mineral oil or Mineral Lube. Oil with a yellowish color that you used for jacks, pressure washers, circulating machine oil and single stage compressors that dont run all day. They have different products for machine oil now

Our latest compressor is a John Deere gas two-stage compressor. Nice assembled in the US unit with a Honda motor and the compressor made in you know where, All it recommends for oil is 30W non detergent which John Deere does not sell. Havent changed the oil yet but will use the Mobil 427. The compressor head gets stinking hot.

If you have smaller or limited use larger compressor shouldn't be a problem to use a name brand ND 30W oil rather than the more expensive small containers of industrial oil

 

[seber]

Under no circumstances would I ever consider hydraulic fluid for a lubricant anywhere. Hydraulic fluids are made to be hygroscopic in nature. That is a killer for rust prone parts. I once was watching a new design I had put into production on the floor and noticed rust colored oil working out through the top of the bearing shafts on several of the working heads. After some investigation I determined that a new engineer had switched the working oil on the floor to hydraulic fluid. What was coming out the top of the heads was rust. Thousands of dollars worth of bearings and untold labor was the result.

 

[WittHay]

Dont know what hydraulic fluid is but hydraulic oil is used all the time to lubricate bearings and gears in tractor transmissions and rear drives.

We are probably using different terminology. There is a difference between Walmart 30W oil that is yellow and good to maybe 150 degrees.and something like the Mobil ISO100 that is clear and is rated at 220 degrees. Its all based on mineral oils that have different additives including rust and oxidation prevention.

Does it matter if somebody calls it cheap stuff or good stuff , homeowner or industrial, mineral or hydraulic oil

 

[MrSurly]

Hydraulic fluids are made to be hygroscopic in nature.

I'm sorry, but ...what?

Are you speaking of what most of us think of when we say "hydraulic oil" (tractor fluid) (R&O)? or are you referring to something entirely different?
Brake fluid (DOT3) as an example is a "hydraulic fluid" that IS hygroscopic... but it isn't used as a lubricant in it's typical application. almost anything including water *can be* a hydraulic fluid, so I'm wondering what you are specifically referring to.
I would be surprised (to put it mildy) if our typical 'hydraulic oil' is actually hygroscopic.

 

[bob15]

Under no circumstances would I ever consider hydraulic fluid for a lubricant anywhere. Hydraulic fluids are made to be hygroscopic in nature. That is a killer for rust prone parts. I once was watching a new design I had put into production on the floor and noticed rust colored oil working out through the top of the bearing shafts on several of the working heads. After some investigation I determined that a new engineer had switched the working oil on the floor to hydraulic fluid. What was coming out the top of the heads was rust. Thousands of dollars worth of bearings and untold labor was the result.

Do you realize that farm tractors use hydraulic fluid as a lubricant for the transmission, final gears and in most cases in their brakes. Hydraulic fluid isn't hygroscopic.

Here is what Mother Deere has to say about their hydraulic fluid:

Functions:
Because transmission and hydraulic oil must perform many different tasks at the same time, there is very little margin for error. To understand the complexity of transmission – hydraulic oil, let’s review its functions:
1) Prevents wear of high-torque, heavy-loaded gears and bearings.
2) Provides wear and corrosion protection for the hydraulic pump.
3) Provides proper friction for clutches to engage and absorb shock loads without excessive slipping or abrupt shifts.
4) Withstands extreme pressures in the hydraulic system without breaking down.
5) Prevents the formation of deposits on all internal parts.
6) Prevents foam and water damage to all internal parts.
7) Provides proper friction for brakes to ensure low chatter, long life, and high capacity.
HY-GARD AND LOW-VISCOSITY HY-GARD TRANSMISSION AND HYDRAULIC OIL
Hy-Gard and Low-Viscosity Hy-Gard transmission and hydraulic oils are unique oils developed by John Deere engineers to meet the exact needs of John Deere machines. Both Hy-Gard fluids are multi-viscosity fluids with high-viscosity index. Low-Viscosity Hy-Gard has an ISO 32 Viscosity
Grade. Hy-Gard viscosity places it between ISO 46 and 68 grades. Hy-Gard may be used in many applications specifying either of these grades.
Low-Viscosity Hy-Gard has the same performance specifications as Hy-Gard and can be used as a replacement for Hy-Gard in cold weather.

Applications:
• The exclusive Hy-Gard formula was designed for use in John Deere equipment; however, it can also be used in many non-John Deere transmission and hydraulic systems.
• Low-Viscosity Hy-Gard is used for factory fill in many machines. Consult the machine’s operator’s manual to determine what machines require Low-
Viscosity Hy-Gard. It is also used as a replacement for Hy-Gard in cold-weather applications.
• Low-Viscosity Hy-Gard replaces John Deere All-Weather Hydrostatic Fluid and should be used as a direct replacement for all applications recommending hydrostatic fluid.
• Low-Viscosity Hy-Gard is compatible with hydrostatic fluid and can be added to systems which contain hydrostatic fluid.
Features:
• Performance tested both in the lab and in the field, and approved by John Deere engineers to meet the increased demands for performance and protection of transmissions and hydraulic systems.
• A polymeric viscosity improver helps Hy-Gard to retain its proper viscosity over a wide range of operating temperatures. For Hy-Gard to work
efficiently, it must flow readily through any part of the system. Oil that is too light can cause increased wear. Oil that is too heavy will cause sluggish operation and lower mechanical efficiency.
• Reduces wet-brake chatter and ensures high braking capacity.
• Superior wet-clutch performance smoothes clutch operation.
• High tolerance to water contamination without sludge formation, which could cause filter clogging and hydraulic-system malfunction. The
anti-oxidation capability allows the oil to work properly at high temperatures, helping keep transmissions and hydraulic system parts clean.
• Provides protection against rust and corrosion, particularly during low-use periods.
• Anti-wear additives keep gear and bearing wear to a minimum. The extreme-pressure film in Hy-Gard helps prevent metal-to-metal

 

[bob15]

If you not interested don't read the thread.

As people are saying we use so little why does it matter. It curiosity. I have done some looking on the web and have not seen anything conclusive.

I want to know if there is a significant difference between a $5 quart of non detergent oil and the $15 quart of compressor oil. Maybe spending 3 times as much makes us feel like we are doing the right thing while we are being fleeced.

If you want, try contacting these guys. They produce a very good product, but also are good with customer service.

https://www.lelubricants.com/

 

[seber]

Hydraulic oil and fluid are the same thing. I got used to calling it fluid so people would understand it is not the same as straight oil. It is fine in a sealed case where water cannot get in. Transmissions are exactly that. Open systems are a different situation. If your compressor is a sealed case, no problem. If it is vented, now you have water vapor collection.

 

[bob15]

Hydraulic oil and fluid are the same thing. I got used to calling it fluid so people would understand it is not the same as straight oil. It is fine in a sealed case where water cannot get in. Transmissions are exactly that. Open systems are a different situation. If your compressor is a sealed case, no problem. If it is vented, now you have water vapor collection.

But you were saying that hydraulic fluid is hygroscopic, which it is not. Hydraulic fluid will prevent rust and it doesn't absorb water. What was the fluid that the engineer spec'd?

Brake fluid is hygroscopic (except for DOT 5) and absorbs water.

That is a huge difference in liquid chemistry make-up, hydraulic fluid and brake fluid.

 

[dnschmidt]

As Shakespeare once wrote: "Much ado about nothing."

 

[American Locomotive]

Dont know what hydraulic fluid is but hydraulic oil is used all the time to lubricate bearings and gears in tractor transmissions and rear drives.

We are probably using different terminology. There is a difference between Walmart 30W oil that is yellow and good to maybe 150 degrees.and something like the Mobil ISO100 that is clear and is rated at 220 degrees. Its all based on mineral oils that have different additives including rust and oxidation prevention.

Does it matter if somebody calls it cheap stuff or good stuff , homeowner or industrial, mineral or hydraulic oil

What makes you think Walmart oil is only good for 150 degrees? Most automotive engines typically run the oil around 180-200 degrees. Air cooled engines can have oil temperatures exceeding 250 degrees.

My little old 2 cyl single stage Quincy has been running 10w30 for 10 years now. I don't think it really matters for most home compressors.

 

[sberry]

Amsoil claims 8x the service life vs generic dino, it's a claim fwiw. Makes some sense in hi value pumps with a hard life. I wanna change my steamer again, looking a little dingy.