Bauer compressor oil

[swamp diver]

Actually I have noted that with a few petroleum based oils locally. Here mineral (or petroleum based) oils are used extensively and I often used to see a colour difference when purchasing, (ie) darker... especially when purchased in smaller quantities usually in clear or semi transparent plastic bottles, obviously decanted by the supplier from the larger original drums.

Later I bought the oil in drum form from the manufacturer and found the original manufacturers drums were a very dense plastic, yellow or black in colour which obviously prevented sunlight reaching the oil, and oil stored in these drums even for extended periods of 8 months or more never darkened or changed colour.

I often wondered if the colour change signified a certain degradation of some of the additives in the oil and I asked quite a few people about it, but in general the consensus was "No", although I could never find any firm conclusive evidence to prove the colour change was detrimental to the oil, by the same token, I could never really find any evidence to prove it wasn't either.

I would be interested to hear what would be your take, or the boards opinion on this.?

Very good questions.

In general as an oil is exposed to the ambient environment it will slowly oxidize and turn darker. The rate of this color change really depends on the storage conditions which include ambient temperature cycling, the volume of air sitting above the oil, and the anti-oxidant additive(s) treat rate.

Almost all the oils will have at least one or two anti-oxidants added to the base oil in order to slow down the rate of oxidative degradation. The rate of degradation will be higher if you store the oil at higher temperatures or if it is not stored in a climate controlled facility in order to avoid temperature cycling. It is best stored at 20 C rather than being exposed to -15 C to 30 C outdoors in the garage.

Also unopened containers with very little air on top of the oil will oxidize at a much slower rate than a container that is only half full so if you are using the oil at a slow rate it would be better to transfer the oil from a 45 gallon drum to 4 gallon pails in order to reduce the amount of air exposure.

Ultraviolet exposure will also darken the oil but this is generally not significant.

The question really comes down to how long is the shell-life for the various oil types. You'll find various opinions on this but most manufacturers will tell you 10 years for an unopened synthetic (the oil will be much darker at 10 years) and probably 2 years for a mineral oil. We actually did look at the rate of degradation of mineral oils and were quite surprised to find that the oil stored outdoors in a 45 gallon drum which was half full and two years old at the time of sampling had lost all of its additive package either through degradation within the mineral oil or possibly evaporation. This also explained the poor oil analysis results we were obtaining at the end of the oil change interval from the compressor.

I'd say therefore that a slight darkening of the oil over time is not significant, but leaving your mineral oil in a half full 45 gallon drum at 30 C will be after a year or more. Keep the oil at 20 C and reduce the container size over time to minimize air exposure and you'll likely get 2 to 3 years shelf life from the oil. If you are unsure send a new sample of oil and the older sample to the lab and look at the ICP metals which are in the additive packages. Once these are at 75% of the new oil's values you know the oil has just about reached its best before date.

In these pics you can see that the color of the new synthetic oils vary considerably so the color change with normal aging will also vary. The mineral oils such as the Shell Corena P122 and P150 are generally darker to begin with since these oils are refined from crude oil.

The compressor environment is essentially like an oxidative test bomb with the water, heat, high ppO2, and iron wear products. As a result both the mineral and synthetic oils will show thermal and oxidative degradation at a higher rate making the oil much darker as can be seen in the used Corena mineral oil after 3 months of use.

 

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Many thanks, thats an excellent, very informative answer swamp diver.
As locally most operators use the Corena P150 it is especially useful. I really like the tip to keep moving the oil to smaller containers to keep the air above the oil minimal, makes perfect sense to me and something one can put into practice very easily.

 

[IyaDiver]

Bauer oil from Bauer Europe is not the same as Bauer Oil in USA market.

USA Bauer use Chemlube, European Bauer at the least for the mineral they use Shell.
For up to 2006 or so, European Bauer synthetic oil N28355 was indicated as Shell.
Now they European Bauer removed the information on their synthetic and mineral oil being from Shell.

In the old days, Bauer Mineral oil N22138 was indicated as Shell Corena P150
COMPRESSOR OIL

European Bauer mineral oil is darker than the synthetic one.
European Bauer synthetic oil is very light color nice golden, like cooking oil and it smell VERY PLASTIC ..........yes.

The typical very plastic smell of Bauer synthetic oil N28355, is a dead give away it is a Bauer's synthetic oil.
The plastic smell is much stonger than even the syntetic Mobil 1 engine oil.

.

 

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Yes, locally I think Chemlube is very difficult to obtain as well. I believe The "LM" oil referred to in the attachment you posted is "Liquid Moly 750"?, also very difficult to obtain here unfortunately, so Locally Anderol 755 is used when a synthetic is required, but from my experience it doesn't smell like plastic and it certainly darkens when badly stored as Swamp diver mentioned, so its likely not the one the OP is referring to.

 

[rddvet]

Is anyone familiar with UL-751 synthetic oil. I bought a K-14 and a local compressor guy helped to rebuild it and sold me this oil for nitrox use. It is branded with his company name, and I suspect it is a well known oil he rebrands and resells. I could be wrong though, it may be a normal brand with his sticker slapped on it. He sells the oil to many of the tech shops in Fl whose compressors he services.

 

[widget]

I think its a Chemlube product (ie) Chemlube UL-751 (you can also get UL-800 as well I believe) - as I seem to recall seeing it as recommended in a compressor manual somewhere sometime back. I am sure folk more familiar with the Chemlube line of lubricants will know for sure, but, that is my recollection.

 

[IyaDiver]

Hi Widget,

Bauer N28355 synthetic even kept 2 years on its plastic bottle will not go brown.
This is relatively stable 30C ambient temp and no sunlight.
When used in a compressor, depending on the amount of heat, it will go darker within 250 hours of use as it also take in all the oxidation and the dirt the engine produce. This is based from my experience.

I would avoid oil more than 2 years from year of production, if I have the choice.
European Bauer does not label date on their oil.

If I may advice those using European Bauer oil and refering to their oil list
http://www.bauer.uk.com/Bauer/Shooting/products/Spares/Lubricating Oil List.pdf

Please don't use it till 2,000 hours or 2 years, say on a Mariner 200 K120.2 block.
This is way too risky and totally not making sense.

Look at Bauer Parts List. See Class A to C which are 500, 1,000 and 2000 hours change.
http://www.bauer-kompressoren.de/pdf/produkte/ersatzteillisten/profi-line2/TCMP2-3_2.pdf
1,000 hours is 500 + 1,000 hours job.
2,000 hours is 500 + 1,000 + 2,000 hours job.

How in the world one is adviced to change all valves at 2nd and 3rd stage and including floating piston at 1,000 hours, while the oil change is adviced at 2,000 hours ?

The oil filter is so small and so filthy at a mere 250 hours at 30C ambient temperature, I am sure clogging will happen before hitting 2,000 hours. 1,350 RPM is a fast machine, if a very low RPM machine I may believe the 2,000 hours oil change. But me being in the tropics....no way I will allow beyond 250 hours.
At 90% humidty, 1st and 2nd stage piston blow by is simply pushing much water into the oil...its scarry for a 3 stage K120.2 block where the 1st to 2nd stage does not get the water separator.

.

 

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Yes, I hear what you say Iyadiver, locally as I mentioned almost everyone uses Shell Corena S2 P150 as it is the most easily available. I am not sure which oil Bauer locally uses and I am not familiar with the N28355 serial number you mention, locally I mostly see N22138 which is a mineral oil (and crosses nicely with the Shell product) and N19745 which is a synthetic (and crosses nicely with the Anderol 755). So I would guess locally we are using different manufacturers oils to both Europe and the USA.

That said, I have only ever used Corena p150 mineral oil in all our machines, and, even in the tough environment our machines operated in and in the 30 odd years we had compressors, we never had a failure related to oils.
Perhaps we were lucky , I dont know, but we were pedantic about oil changes every 500 hours or so and perhaps that played a part, but I have to say I really have great faith in the Shell Corena P product.

 

[Scubadude_LA]

I use Chemlube 751 in my Oceanus, so far so good, stickin nitrox for 50 or so hours. I see 800 in this thread with reference to Wookie (post #2), but I thought I saw somewhere he had issues with the 800, ring seal issues are something, crap, I need to find the spot I read that...