Air compressor oil

[cwsmith]

Thanks very much for the suggestions.

I actually presented this problem to one of my friends in the Engineering Dept (I worked for I-R back then... only way I could have afforded an I-R compressor at the time).

We used a synthetic, called Anderall or something like that.

The compressor was long-ago recalled, so don't have it anymore. I now use this extremely noisey Craftsman 33-gal oil-less, which was Made in the U.S.A. by the DeVilbiss company. Gotta wear ear plugs AND ear phones, but thing has run faithfully (and loudly) for the last eight years.

The little $100 Craftsman 2-gal does use 30-wt, as mentioned. But it's alway in the house and we're both warm. I don't do that "cold" stuff too well now that I'm retired.

CWS

[cabinetman]

To avoid any confusion, by "motor oil" I mean commercially available API certified oil. All current API grades of oil are detergent oil and have been for decades.

That is patently false. Where did you read that?? If necessary, I can copy the label off one of my containers that show how incorrect you are with that statement.

By current definition, "motor oil" means detergent oil. There terms are sometimes misused or interchanges by the misinformed in casual discussions , but SAE and API define motor oil as detergent oil in current usage (and have since 1951). API-SA oil is a non-detergent oil and is still available for use in antique cars such as the Model T, but is considered "obsolete" by API.

"Motor oil" to you may mean "detergent oil", which goes along with your statement about misused terms by the misinformed. You got part of what you searched out right in that API-SA is a non-detergent oil. One line before that you say SAE and API define motor oil as detergent.

What you are confused about from what you read is that a non-detergent oil should not be used in an automobile engine. You can discuss all you want, to explain what "motor oil" means.

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[woodturner]

Thanks very much for the suggestions.

You are quite welcome, I'm happy to share my knowledge and experience to help others.

I actually presented this problem to one of my friends in the Engineering Dept (I worked for I-R back then... only way I could have afforded an I-R compressor at the time).

We used a synthetic, called Anderall or something like that.

I assume he suggested the synthetic? Did you try the Anderol? If so, how much did it help?

[jnesmith]

That is patently false. Where did you read that?? If necessary, I can copy the label off one of my containers that show how incorrect you are with that statement.



"Motor oil" to you may mean "detergent oil", which goes along with your statement about misused terms by the misinformed. You got part of what you searched out right in that API-SA is a non-detergent oil. One line before that you say SAE and API define motor oil as detergent.

What you are confused about from what you read is that a non-detergent oil should not be used in an automobile engine. You can discuss all you want, to explain what "motor oil" means.

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Let's simplify things for simple minds like mine.

If it is a "detergent oil", will it be clearly labeled as "detergent oil"?

If it is a "non-detergent oil", will it be clearly labeled as "non-detergent oil"?

[cabinetman]

Let's simplify things for simple minds like mine.

If it is a "detergent oil", will it be clearly labeled as "detergent oil"?

If it is a "non-detergent oil", will it be clearly labeled as "non-detergent oil"?

Yes on both counts.

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[woodturner]

If it is a "detergent oil", will it be clearly labeled as "detergent oil"?

If it is a "non-detergent oil", will it be clearly labeled as "non-detergent oil"?

Unfortunately, not necessarily. Non-detergent oil will usually, but not always, be labelled as such. Motor oil is detergent oil by SAE and API definition, and therefore is sometimes not clearly labelled as "detergent".

If you aren't sure, you can check the MSDS on the manufacturer's web site or at the store where you buy the oil. If the MSDS lists "additives", "detergents" or "solvents", it's a detergent oil. For example, the MSDS for Pennzoil says it contains "Highly refined mineral oils and additives", indicating it is a detergent oil.

It's always wise to verify information one reads on the internet, particularly when some posters seem confused and appear to be operating outside their area of expertise. To my knowledge, I am the only poster in this thread with education and experience in the field of tribology.

Another source of information a lot of people seem to like is "Bob is the oil guy". Usually the information there is pretty decent, and some of us who post there are in the industry. As with any public site, there are a few people who post inaccurate information, but by and large the information is pretty good.

Edit: Another poster mentioned the "Bob is the oil guy" site might not have accurate information, so please exercise caution when using that site

[Cochese]

BITOG used to be really good, but a lot of the actual experts left awhile back and their mantles were assumed by pretend experts. I don't know if that has started to change back over, but it stopped being a credible source awhile back for the gearheads, because you'd get diametrically opposing answers.

But I haven't built engines in awhile, so I don't know how accurate that statement is these days.

[cabinetman]

Unfortunately, not necessarily. Non-detergent oil will usually, but not always, be labelled as such. Motor oil is detergent oil by SAE and API definition, and therefore is sometimes not clearly labelled as "detergent".

The information you read to respond to this thread has you confused. All motor oil will be labeled as to what they are.

If you aren't sure, you can check the MSDS on the manufacturer's web site or at the store where you buy the oil. If the MSDS lists "additives", "detergents" or "solvents", it's a detergent oil. For example, the MSDS for Pennzoil says it contains "Highly refined mineral oils and additives", indicating it is a detergent oil.

In simple terms, the label will say "non-detergent" if it is, it will be suitable for air compressors.

To my knowledge, I am the only poster in this thread with education and experience in the field of tribology.

That's interesting...tell us all about it.

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[woodturner]

BITOG used to be really good, but a lot of the actual experts left awhile back and their mantles were assumed by pretend experts. I don't know if that has started to change back over, but it stopped being a credible source awhile back for the gearheads, because you'd get diametrically opposing answers.

Thanks for the "heads up" and that is good to know - I haven't really posted at or kept up with that site for a few years. I just mentioned it because a lot of people seem to like it. I'll be more cautious about recommending it in the future.

It can be difficult to validate information posted on the internet. We (Cylab) have been doing some research under contract to CERT to "validate" credentials while still maintaining safety. Traditionally people have used certificate or authentication sites, but some of them were hacked a few months ago, so now we cannot even trust the "trusted sites". More and more, it seems like the transparency movement may be the only truly viable option.

[Cochese]

Thanks for the "heads up" and that is good to know - I haven't really posted at or kept up with that site for a few years. I just mentioned it because a lot of people seem to like it. I'll be more cautious about recommending it in the future.

Yeah, I haven't kept up with the site for a few years myself, so I caution that my info on it may not be the most current. However, from some posters on my car forums indicates that it is still true. Good info and bad info, unfortunately some may not know which is which so I temper my recommendation. When I get back into building this motor I have my eye on, I might delve back into it. As it is, the day job and the wood hobby have my full attention now.

What does one do as a tribologist, if you don't mind me asking? I always found physics fascinating, but never bothered to apply any of it.

[jnesmith]

Yes on both counts.

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Interesting. I just checked a bottle of 4-cycle "engine oil", and nowhere does it say anything about detergent or non-detergent, nor "additives", or anything else that would indicate one way or the other. Maybe "engine oil" plays by different rules.

The only "motor oil" I have at the moment is synthetic, so I don't think that could be used to test the theory.

Thanks for the info.

[cabinetman]

It's unfortunate that 'pretend experts' seem to end up on many sites and add confusion to good discussions. I guess that is just the bane of the internet.

I agree with that 100%. Many of them make false claims as to their credentials. And you're right they do add confusion. Some even re-word information taken from internet sites. So, when they claim to be 'experts' try to remember that they can say whatever they want. And, as you inferred, it's prevalent on the internet. Some are more overt than others. Thanks for the reminder.

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[woodturner]

What does one do as a tribologist, if you don't mind me asking? I always found physics fascinating, but never bothered to apply any of it.

Tribology is usually defined as the study of interacting surfaces in relative motion - which is just a fancy way of saying it's the study of lubricants and friction in applications such as bearings. Tribologists in academic research explore new materials, methods, and ideas and publish research papers to share new knowledge.

In industry, a tribologist might work for an oil company developing "better" oils - better lubricating properties, lower cost, new characteristics such as better detergents, etc.

My first Ph.D and primary research area is electrical engineering, specifically relating to computer architecture, communication security, and parallel processing. My original motivation for the ME was MEMS, but a retiring colleague pulled me into his research group to fill in. Our (a joint research group with several ME faculty) current work in tribology is investigating the modulation of electric currents to reduce friction in large motors and engines. While the observation that electric currents can affect friction and wear is widely reported, the mechanism of how and why is not well understood. In other words, we are trying to learn why electric currents affect friction with the goal of using currents in controlled ways to reduce friction.

Which is a complicated way of saying that, like most professors, when I am not teaching classes or advising grad students, I work with computer models and simulations to test out hypotheses and write research papers.

[Cochese]

I agree with that 100%. Many of them make false claims as to their credentials. And you're right they do add confusion. Some even re-word information taken from internet sites. So, when they claim to be 'experts' try to remember that they can say whatever they want. And, as you inferred, it's prevalent on the internet. Some are more overt than others. Thanks for the reminder.

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Are you trying to call him a liar without directly saying it?

[BobSch]

Enough with the sniping already!

If it doesn't say "non-detergent" or "compressor oil" it's not getting close to my compressor.