2,000 hours Bauer oil change reccomendation is worrying me

[IyaDiver]

Gents,

I never worry about water-in-oil in engines, because the oil temperature is high enough to evaporate any water from condensation.

What I worry is Bauer's overly optimistic reccomendation of 2,000 hours / 2 years using its top of the line N28355 synthetic oil for air. I am refering to Bauer Germany version of the User Manual. In the USA it is probably different manual...maybe.

Since compressor does not get its oil contaminated by fuel's combustion by-product like in an engine, it should stays pretty clean. Temperature wise I can say 50-60C is the hottest temperature at the oil filter output ( for my Bauer ), perhaps some hot spot at the cylinders where compression takes place but I guarantee the oil is much cooler than in an engine. Wear and tear contamination will be metal parts, since Bauer Mariner is air cooled, there is no possibility of engine coolant contaminating the oil from worn out gaskets or whatever. This leave us with water in oil introduced by ambient air and whatever water vapor piston blow-by will throw at the oil.

Nightime and daytime water condensation in oil crankcase part of the block is one thing, but what worry me a lot is the 5% piston blow by of the current Mariner block, its a 200 liter/minute or 7CFM.

5% will represent blow-by from possibly combination of 3 stages, the wettest will be the 1st stage because there is no water separator there. 2nd & 3rd stage piston blow-by will probably be 98.xx % drier because of the water separator function.

5% of 200 liter/minute is 10 liters and 1/3 of that is wet air from only cylinder 1 , that is 3.33 liters of air x 60 minutes run = 199.8 liters, let's make it 200 liters.

Bauer Mariner sucks air out of the crankcase to feed oil mist into cylinder 1. Whatever moist blow-by air probably get sucked too due to suction of cylinder 1 piston........but how much actually got sucked ? The oil filler neck has o-ring, so its quite a restriction to suck all air produced by piston blow by, the air coming thru the snorkle will be an easier path for the piston to suck. Dang...... suck here suck there....sounds like a porn flick

Assuming 90% of that 200 liters per hour of moist blow-by air will be removed by cylinder #1 suction. I still will get 10% of 200 liters = 20 liters per hour of moist air per 1 hour compressor run.

Now, I do not know how much positive pressure the compressor block will get during a compressor run. I am just trying to calculate the potential volume of water vapor introduced to the oil from piston blow-by, per hour. If the block stay at 1 ATM all the time, in theory there won't be extra air added, just air exchange. Bauer/compressor experts in this forum, please help me out in this.

If 20 liter worth of moist air is being squeezed of its moisture in the compressor crankcase per hour, there will be a lot of water in 200 hours of compressor operation, assuming 80% humidity. 20 liter x 200 hours is 4,000 liters or near two tanks full of 80CF.

Again assuming I screwed up the calculation and only 10% of 4,000 liters of air is what can contribute to water vapor conteminating the oil, I still have 400 liters of air worth of moisture to worry. 400 liters of wet 80% humidity air can juice out easy 3cc of water.

The Mariner block oil capacity is 2,800cc. That 3cc or milli liter is 1071 PPM of water in a 2,800cc of oil.

Oil engineer will find 1,000 PPM of water in oil scarry and bearing life will be reduced a great deal.


I am not very sure how to interpret the darker color of a used compressor oil , compared to light yellow color it is when brand new. How dirty is dirty ?

Oil do oxidize during use, or when exposed to metals and so on but what kind of color darkening resulted from that, if the water contemination equation is removed ?

Milky oil is sure sign of too much water, that I know. I have flooded ( and stalled ) my car engine twice in my lifetime. Its 4 feet of water for a small sedan, driving it thru a major flood... and feet of water in a Suzuki Vitara without a snorkle..

Combustion by-product in say a diesel engine or gasoline engine oil will make the oil look "dirty" and "black" oil is what diesel engine will produce in just 20 hours of engine run.

Using Chemlube 800 oil data sheet with its claimed excellent demulsibility, it is said that the oil is engineered to keep water in suspension as free water and not emulsified bla bla bla. If Bauer N28355 synthetic is as good as Chemlube 800 or equivalent, I may say that it seems 200 hours is the best I will get for my compressor working conditions/profile and at up to 33C ambient temperature.

This is a drain test I did on a 200 hours oil life :
- Compressor rested for 12 hours.
- Drain 500cc of the oil from the drain pipe, dang I should have drained all
- See water droplets in oil.....yep quite a few.
- Test water droplets using crackle/cooking test.....yep it blew like fire crackers

Findings :
I think the specific gravity of the Bauer oil is quite high. It takes approx 15 minutes for water droplets to drop to the bottom of the pyrex cup. I usually look for water in diesel fuel but never in oil like this and water in a 0.85 SG diesel fuel will hit the bottom of the container pretty fast.

Water saturation in this 200 hours old oil has surely hit the roof. Otherwise it will be dissolved in the oil and at 30C oil temperature, it is said it can dissolved up to 250 ppm or so and increasing with temperature and up to a certain limit.
Detecting and Controlling Water in Oil
How Water Causes Bearing Failure

Any oil or compressor expert opinions to add to this post , will be most appreciated.

Attached :
-Brand new oil from Bauer factory after 100 hours only. Bloody dirty !!
-New Oil
-200 hours old oil ( second oil change )


Thanks
IYA

 

[IyaDiver]

This is the 200 hours oil and ist water droplets ( free water ) close up

 

[IyaDiver]

Crackle test......popcorn time...

 

[IyaDiver]

Conclusion :

- The oil is probably a good grade, it can keep the water as free water.
- How much dissolved water in the oil............no idea.
- Is water in oil as free water safe for my compressor........hell no ! I can't have small water droplets lubricating the con-rod bearing or crankshaft bearing or the 3rd stage final piston or any piston liners for that matter.

Solution ? :
What I intend to do is to get a FleetGuard diesel fuel filter, it is the FS1000. I will try to remove the free water using Fleetguard water adbsorbent media called Stratapore. I will clean the oil to 7 or so micron and will trap the free water. Between new and 200 hours oil life, there will be water droplets formed bit by bit in my oil anyway and that is an operational risk. I can do this oil "polishing" per 10 days. The same thing I do for my client's fuel in their yachts. I polish it every few days.

A china made gear pump capable of pumping cool 40W oil will set me back US$400 at the most. That FleetGuard filter bracket maybe another US$100 or so, the FS1000 fuel filter probably US$20. If I pump slowly I probably will get away using this fuel filter as oil filter. Otherwise I get an oil filter from Fleetguard with Stratapore media.

The cost of this bloody expensive Bauer syn oil in my country is US$85 per liter or US$321 per gallon. In Thailand it is US$54 per liter. In USA a Chemlube 800 is only like US$60 - 70 per US Gallon ( 3.78 liters ).......I am sooooo jelous.

If I do 200 hours oil change and still get water droplets in them, that will be US$85 x 2.8 liters x 5 times = U$1,190 oil expenses per 1,000 hours........

I will import Chemlube 800 asap but by air is not allowed, must go by sea...damn slow.

Dang...... I envy you guys owning compressor in USA.:kiss2:

 

[IyaDiver]

Amount of water in an oil change after 200 hours and only 5 months........
I guess by cutting down even to 25% only of Bauer reccomendation or 500 hours oil change or say per 6-8 months, a lot of parts will be worn out by then and by 2,000 operating hours it will be an expensive maintenance program.

 

[rjack321]

The water is coming from the compression of the air. That's why you have condensors and filters, upon compression the air is 100%+ relative humidity. You are never going to keep the oil water-free and its not necessary to do so.

I would still change your oil much more frequently than 2,000hrs. And use a synthetic rather than a mineral oil.

 

[IyaDiver]

Hi Jack,

I am using the Bauer synthetic oil.

Of course the water in oil comes from compression and also condensation of the crankcase at night.
It is very necessary to keep water off the lubrication oil in crankcase. Oil in the the air stream, that I can't do anything about it since oil mist is injected for lubrication.

I am now doing 200 hours oil life, but looking at the total accumulated water in lubrication oil even for 200 hours operation, I am keen to remove those free water.

In a hydraulic system where oil temperature does not heat up like in an engine oil and evaporate the traces of free water, they have special filters to remove the free water. That is exactly what I plan to do.

Many industrial setting has some kind of "polishing" mobile oil pump with special filters or/and centrifugal water-dirt separators. The crew goes around "polishing" oil in gearboxes and other machineries while removing freewater.

This Bauer oil demulsibility is not too bad, even without a pump and a filter, if I have the patience to drain the oil every say 20 hours to those glass Pyrex and let the water settled to the bottom for an hour, I can remove some of them by gravity since the free water sort of "floc" itself and as seen on the photos, the free water seems to love to stick on the glass bottom of the Pyrex.

No maintenance crew dealing with lubication oil will want any water in their oil, there are ways to remove even dissolved water but the equipment is rather expensive. I just want to get rid of free water in the oil as fast and as much as I can. Water in any lubricating oil is a big NO-NO.

Thanks
Iya

 

[rjack321]

There will always be water in compressor oil. Not much but there will be free water. The dissolved fraction is so tiny its inconsequential.

Bauer compressors can last for 10,000+ hours without your modifications. Just regular maintenance. So adding extra oil "filters" and such can do nothing but screw up a proven design which works.

 

[dannobee]

Running the compressor at operating temperature will also remove much of the water, as it will boil off.

Short runs for limited time will not allow the oil to reach operating temperatures and water will accumulate in the oil.

I'm sure it tells you this in the owner's manual, too.

 

[IyaDiver]

1st thing 1st : HAPPY NEW YEAR GUYS

Hello Bee,

My Bauer oil temperature won't hit above 60C even in 2 hours run. The cylinder head will hit above 130+C easy in under 30 minutes run, if I do not use my extra powerful axial blower. See my other post on the cylinder head temperature monitoring. http://www.scubaboard.com/forums/co...-typical-operational-temperature-tropics.html
There is hardly any chance the free water in oil will evaporate. 60C is a good thing from oil life point of view and its vicosity stability but bad for free water accumulation which can't evaporate. Can't win both.

Do you have an oil temperature gauge on your compressor ? How hot is the oil in your compressor after 1 hour run ?



Hello Jack,

Yes, 10,000+ hours is achievable but how much parts replacement to achieve that ?

Look at how Bauer "improved" their design over time :

Old Mariner block, no oil filter. Oil capacity 1.6 liters. >750 psi oil pressure. No piston rings for 3rd stage floating piston.

Newer Mariner block, has oil filter. Oil capacity 2.8 liters. 75 psi oil pressure. With piston rings for 3rd stage floating piston.

Now comes the funny part. When Bauer first use the newer block and the piston rings for 3rd stage floating piston sometime in 2002-2003 for Mariner 320 ( I only follow Bauer products up to Mariner 250 ), and all the marketing hype about it being very reliable and bla bla bla. Their part list book DID NOT state 1,000 hours life on it. Go to Mariner 320 of 2002 , page 11 of the PDF or page TM320-9 paper print, item 90:
http://www.bauer-kompressoren.de/pdf/produkte/ersatzteillisten/mariner320/2002-07-01_tm320-1_0.pdf

The Capitano/Mariner using the same ringed 3rd stage floating piston in 2004, also has no 1000 hours life time on it : ( Page 14 PDF or page TCMPII -12 paper print, item 90)
http://www.bauer-kompressoren.de/pdf/produkte/ersatzteillisten/profi-line2/TCMP2-1_0.pdf

By 2005, Bauer probably found out that the ringed floating piston ain't as good as they hope it would be. Bauer then put 1000 hours life on the ring floating piston for Capitano/Mariner family. ( Page 16 of PDF or TCMII-16 paper print, item 90 )
http://www.bauer-kompressoren.de/pdf/produkte/ersatzteillisten/profi-line2/TCMP2-2_1.pdf


Later in 2006 they apply the same 1000 hours service live for the ringed floating piston on the Mariner 320 ( Page 8 of PDF or page TM32- 6 on paper print, item 195 ).
http://www.bauer-kompressoren.de/pdf/produkte/ersatzteillisten/mariner320/2006-01-01_TM320-4_0.pdf

Design improvement is considered only "good" after being tested by end users and proved in the field. So what happened to the new ringed piston 3rd stage design ?
Why from a sudden 2000+ hours life ( no specified life time in Bauer part list should means above 2,000 hours ) suddenly Bauer put a 1,000 hours life on this so called superior long life ringed floating piston ? If they bring it down to 2,000 hours, and indeed it can last for 2,000 hours, then they have spoken true to their claim that this is an improvement of an extra 1,000 hours service life.

This is what Bauer claimed :

The New High Pressure Final Stage

The new high pressure final stage is fitted with piston rings made of a newly developed high tech synthetic material which has proven its superb anti-abrasive properties in long-term tests.

Due to this new technology, oil consumption has been reduced. This advancement has made the compressor run smoother and increased its life.

Source : BAUER COMPRESSORS - Products - New Compressor Blocks for Breathing Air and Industry


Proven enough that as of early as year 2005 or after 3 years of customers testing/running , this so called proven high tech synthetic pistons rings have proved be a only worth 1,000 hours service life, exact same service life as the ring-less floating piston. Where is the improvement then ??

You make your own guess, who is proving for who ?



Sometimes I think Bauer is kind of weird or its technical department goofs off a bit.
Take a look at the Mariner parts manual, in 1997 and prior, they put 2 years service life on the ring-less 3rd stage floating piston P/N 066934. Back then the service interval was :
Code 0 for gasket kits
Code 2 for 2 years maintenance kit
Code 5 for 5 years maitenance kit

Then in 1998 and 1999, they removed service life information for the ring-less floating piston. Maybe someone forgot to marked that "X" at Code B box of ring-less piston for TWO YEARS ?? .


In 1998 and until today Bauer uses operating hours and time period,like most things mechanical :
Code A for 500 hours or as required
Code B for 1,000 hours or at least annually
Code C for 2,000 hours or at least once in two years



With the result of my cylinder head temperature monitoring, if I were Bauer, I would put more effort into designing a new fan pulley that can deliver more air for ambient temp of 30C. Most divings happen in warmer climates anyway. With today's technology they can have an adjustable pitch blades for the pulley blades to get more air flow for various tropical operating condition. Raise the motor power extra 500 watts and it will be easy to extract additional 1000-1200 CFM of air flow.

To note : My adding of oil filters is not on the Bauer oil circuit, it will be a seperate circuit and only will be operated when compressor is not running. Cleaning oil off-line is my intention, not lubing.

You said :
"Bauer compressors can last for 10,000+ hours without your modifications. Just regular maintenance. So adding extra oil "filters" and such can do nothing but screw up a proven design which works. "

If you are getting 10,000+ hours compressor life but with 3rd stage pistons relacement every 1,000 hours as per the book and cylinder 1 and 2 piston/liner sets every say 3,000 hours, is that your definition of a proven design ?
Why do you think there is no room for me to improve it or are you having doubt that by removing free water, I will actually achieve some significant benefits ?

I do not understand how you do not worry of free water in oil when we know the oil pump suction tube is always near the lowest part of the crankcase. Those free water will be forced to lubricate 3rd stage piston and splashed to the crankshaft main bearings for sure. If any free water were to be heated at piston rings to above its boiling point, the liners may be pitted with micro corrosion. We need oil film not water film at those crictical areas. What about the con-rod bearings and the two big cranckshaft's ball bearings ?

Furthermore, the definition of 10,000 hours life........ if a crankshaft were ever replaced within that period, that is not a true 10K hours service life. I call that useful life. If I were to change pistons, liners, con-rods, all bearings and/or without a new crankshaft, that in my book is the ending point of the compressor service life already. After that, it started as zero again and hope the crankshaft and crankcase/block would still be giving another 10K hours. The supporting accesories to make a completely working compressor is expensive. In countries like US where parts price is probably cheapest in the world, replacing a compressor piston+liners+con-rods+ all bearing probably can be a better option than buying a new one. Maybe.

Compressor's cylinder head does not really wear out, there is no combustion or valves perfect sitting to worry. That is one good thing and $$ saver. I guess this is the reason in the US there are many old compressors in service. Here in my country, even at US$12K for a new Mariner 200 ( 7 CFM ) with P21 filter housing, European beautiful carry frame and two Bauer original DIN/YOKE filler hose assy, the above mentioned major over haul parts will still cost too much. Selling the worned out compressor used at US$2,500 to US$3,000 is usually the case and the buyer will be a low budget dive operator, or a low budget dive club who do not know anything about compressor and will learn with great pain later. These will then become the smelly and oily-air producing compressors with self packed filters of unknown filter media quality.


To me the logic is simple. If I can change the ringed floating piston in 2,000-3,000 hours instead of the reccomended 1,000 hours, the approx US$400 oil polishing system I will be installing will pay itself immediately at 1,000 hours of compressor life. The side benefits of other cylinder liners staying healthier over longer period is another $$ saver. Not to mention the frustration and risk if too much oil got injected into the air stream due worn out piston rings and liners which will raise the blow-by oily air volume.
Those extra oily air will then be injected back to cylinder 1. The filter cartridge life will suffer, the activated carbon is rated most likely for a healthy compressor. As the compressor aged prematurely, it is another story alltogether.

There is another irony. Bauer stated 2,000 hours oil life with their synthetic oil but reccomends 1,000 hours life for the 3rd stage ringed floating piston. There never been any machineries I maintained where by the book , the oil life is longer than the parts it is supposed to be lubricating. Even if we halved the oil life to 1,000 hours, it is still a joke. "Please change the ringed 3rd stage floating piston every time you change oil............"

Can't be that Bauer engineers do not know that oil analysis DOES exist. If Bauer does oil analysis per 100 hours at operating ambient temperature of 30C ( say a Miami summer ) before they advice customers that 2,000 hours is the do-able service life of the oil, Bauer will probably find that free water in the oil will be too much even before compressor oil hit 1,000 hours service life, let alone other form of contaminations. Coltri makes more technical sense by reccomending 250 hours oil life ( MCH 30-36 User Manual ).

8,000 hours life claim of high performance oil manufacturers is common, but on what kind of compressor system ? What kind of oil contamination control desiged in to the lubrication system ?


No matter where the water in oil comes from, it will surely fail the test if water is there above 1000 ppm, more so with free water in oil. Some machineries will demand lower than 500 ppm of water in oil.

If we want to follow breathing air quality standard, we must first maintain the machinery that produces this breathing air and it so happened there is a known limit for lubricating oil contamination. It is just regular users do not worry much about oil and take for granted a manufacturer User Manual like a bible. Unless one place the used oil in a clear glass Pyrex like I do and do such test while the oil still has some clarity in it to see free water droplets. Most unlikely the user will only know there is water in oil when the oil has gone milky enough. If the oil is too dirty/dark to be milky, and user uses colored plastic container or metal jerry cans for used oil removal, probably the user will never even know there is a potentially damaging amount of free water in the oil.


I love Bauers, have been and will always be. Bauer is the only brand I will buy at 200 liters per minute class.


I want to achieve 3,000 - 4,000 hours life on that 3rd stage floating piston and hopefully longer on the 1st and 2 cylinders life. My diesel engines can easily achieve 4,000+ hours with compression and oil consumption still within limits. With free water in oil and finer particles removal plus the massive forced cooling I am doing, I hope I can get better life from the Bauer. I think diesel engine compression is a more stressful duty than a Bauer compressor doing compression works.

Its not only the $$ issue, it is the sense of satisfaction of being able pay attention the smallest details, to have less down time on the Mariner and to achieve quality air production consistently.

As IAN/HSM loves to put it : The devil is in the details.

Again ,I hope this 2011 will be a better year for everybody.

IYA