Public apology to GeorgeCLS re Mobil 1 and esters
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MolaKule
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With today's modern POE esters there are no real seal swell problems, and since esters are very polar, they do wet and cling to metals very well.
Some have said that esters have moisture attracting problems, but have never documented that is the case with modern esters. I think what we have here is a case of some people posting old data.
When using a mostly PAO base oil, one uses special diesters for seal swell. Most newer additives come in ester fluids which do not affect seal swell since they ae "mediated' esters.
Mobil hasn't said they're using Alkylated Naphthelenes in Mobil 1, they only stated they are doing some testing using PAO's and NA's, which is what we call in the industry, a "proof of concept."
It will be interesting to see what later results show by using the PAO/AN mix.
My take on the article is this was someone at XOM "spilling the beans" on what they have in fact done with Mobil 1 SuperSyn. That would account for why the Mobil 1 site now goes out of its way NOT to mention esters in the formula, whereas with Tri-Syn it EXPLICITLY mentioned esters as one of the three "synthetic fluids" used.
MolaKule
Staff member
My take on the LnG article was:
"Here is what we're experimenting and testing with and this is what you may see in the near future from XOM."
With crude prices vascillating,
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=4;t=000311;p=1#000000
I can't say I blame them for trying to find less costly alternatives, but they had better be straight with us regarding base oils.
"Here is what we're experimenting and testing with and this is what you may see in the near future from XOM."
With crude prices vascillating,
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=4;t=000311;p=1#000000
I can't say I blame them for trying to find less costly alternatives, but they had better be straight with us regarding base oils.
Well I am a bit lost here .
read member 59's response in the thread .
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=1;t=001714;p=2
MolaKule
Staff member
sbc,
Mobil 1's base is predominately PAO's with some esters of the TME variety and some di-esters for seal swell.
Additives come in "esterified" format for the most part these days, with the sulfur-phosphorus adds being "mediated" and are not corrosive.
Some adds may contain paraffinic mineral oils to reduce cost and concentration, but the percentage of mineral oils is so low as to be inconsequential, i.e., Much Ado about Nothing and old Hat.
Seotaji,
Your question was answered in a previous post that you started. See last paragraph above.
[ March 31, 2004, 05:02 PM: Message edited by: MolaKule ]
Mobil 1's base is predominately PAO's with some esters of the TME variety and some di-esters for seal swell.
Additives come in "esterified" format for the most part these days, with the sulfur-phosphorus adds being "mediated" and are not corrosive.
Some adds may contain paraffinic mineral oils to reduce cost and concentration, but the percentage of mineral oils is so low as to be inconsequential, i.e., Much Ado about Nothing and old Hat.
Seotaji,
Your question was answered in a previous post that you started. See last paragraph above.
[ March 31, 2004, 05:02 PM: Message edited by: MolaKule ]
'Kule: "Some have said that esters have moisture attracting problems, but have never documented that is the case with modern esters. I think what we have here is a case of some people posting old data."
blano and Cujet in two-stroke oil threads in the small engine subforum have claimed serious water absorption and corrosion problems with Red Line's racing 2-stroke oils.
Red Line claims that their fuel system cleaner also removes moisture.
In both cases, modern esters are being blamed (fairly or unfairly) for the ability to attract/absorb moisture.
--- Bror Jace
[ April 01, 2004, 02:24 PM: Message edited by: Bror Jace ]
blano and Cujet in two-stroke oil threads in the small engine subforum have claimed serious water absorption and corrosion problems with Red Line's racing 2-stroke oils.
Red Line claims that their fuel system cleaner also removes moisture.
In both cases, modern esters are being blamed (fairly or unfairly) for the ability to attract/absorb moisture.
--- Bror Jace
[ April 01, 2004, 02:24 PM: Message edited by: Bror Jace ]
So , is this where it stands for now . The non garden variety PAO's , with TME Ester in the formulation and Di-Ester as the seal mediator but still yet some alkylated aromatics for whatever purpose ?
In affect , a PAO/Ester formulated motor oil ?
Would it not be easier to call them and say ,quote:
Originally posted by buster:
I'd like to have Mobil 1 broken down.-Anyone want to chip in and have it analyzed?
He He !
MolaKule
Staff member
I don't disagree with Blano and Cujet and respect them highly. I believe they may have observed corrosion, etc, but what was the root cause?
But here are some questions to consider:
Was the fuel/oil mix tested for water content after it sat in the tank, and if so, was it the esters or the rest of the formulated package that attracted moisture? Did moisture settle in the mix due to tank condensation?
In my view, for this specific case, the question here is not that corrosion was caused by the base oil esters, but the problem may be with the additives and solvents.
All fully synthetic 2-cycle oils (including Mobil's MX2T) contain three major components:
A. Approx. 75% mix of POE and diesters,
B. Approx. 17% Additives such as AW, RI's, and detergents, combustion enhances, emulsifiers, etc.
C. Solvents: 8%
The problem here in my experience is not with Item A, the majority base oil, but with Items B. and C. In other words, additives and solvents can cause corrosion if not in the proper ratios or if they are absent. We know that certain additives don't play well together. If one of the additives attracts moisture during combustion (such as a combustion enhancer), then the cylinders and CC could be blasted with a corrosive mix of spray. Then after the engine cools down and condenses water vapor, parts rust.
What needs to be determined in this case is whether or we have rust due to condensation, or is the corrosion caused during combustion, for example, does the additive package actually contribute to some type of acidic reaction?
I usually find there are more than one cause for any effect.
Just some food for thought.
MolaKule,
I'm going on a tangent here......
Refrigeration POE oils are highly hygroscopic, far more than mineral or PAO based refrigeration oils, which, to be fair are also hygroscopic.
Would it have to be down to the type of esters used, or is it purely a function of the ester being dehydrated for this application ?
The fear of God has been put into everyone using these newer oils, by both the oil companies (Mobil among them) and compressor and component manufacturers, with the POE's coming in tins instead of HDPE (osmosis !), any unused portions to be thrown out, refrigerant driers (which all systems use) having extra acid and moisture absorbing dessicants added, etc.
What would be your take on why these oils are so highly hygroscopic compared to what this industry has used in the past ?
Thanks
Rick
I'm going on a tangent here......
Refrigeration POE oils are highly hygroscopic, far more than mineral or PAO based refrigeration oils, which, to be fair are also hygroscopic.
Would it have to be down to the type of esters used, or is it purely a function of the ester being dehydrated for this application ?
The fear of God has been put into everyone using these newer oils, by both the oil companies (Mobil among them) and compressor and component manufacturers, with the POE's coming in tins instead of HDPE (osmosis !), any unused portions to be thrown out, refrigerant driers (which all systems use) having extra acid and moisture absorbing dessicants added, etc.
What would be your take on why these oils are so highly hygroscopic compared to what this industry has used in the past ?
Thanks
Rick
MolaKule
Staff member
The polygylocol ether esters are highly hygroscopic and must be dehydrated before bottling or application, but the TMP and PE polyol esters are not.
So I would say it's down to the type of ester used.
Oh, and BTW, some companies HAVE used polyglycol ether esters in 2-cycle oils.
[ April 03, 2004, 07:17 PM: Message edited by: MolaKule ]
So I would say it's down to the type of ester used.
Oh, and BTW, some companies HAVE used polyglycol ether esters in 2-cycle oils.
[ April 03, 2004, 07:17 PM: Message edited by: MolaKule ]
Ric,
Indeed, the SHC series of ester refrigerant oils are busted after 2 pours! They are so hygroscopic that water levels exceed specifications after being poured two times from two different containers! It is real, believe me.. Same as with Jet Oils. They are still packaged in metal containers only and shipped with a nitrogen blanket. And then you go into an aviation shop and see a 55 gallon drum with an open top, to not only moisture but dust an dirt! And they wonder why jet engines fail..!!
George Morrison
Indeed, the SHC series of ester refrigerant oils are busted after 2 pours! They are so hygroscopic that water levels exceed specifications after being poured two times from two different containers! It is real, believe me.. Same as with Jet Oils. They are still packaged in metal containers only and shipped with a nitrogen blanket. And then you go into an aviation shop and see a 55 gallon drum with an open top, to not only moisture but dust an dirt! And they wonder why jet engines fail..!!
George Morrison
Thanks George,
It's good to know my handling practices aren't in vain.
I actually sometimes flood a container after opening with dry nitrogen so I can use the rest of the contents rather than throw it out.
I'm not sure if this works, or I'm kidding myself on this one.
I also tend to use the biggest **** driers I can get my hands on on any system I install or service.
It's good to know my handling practices aren't in vain.
I actually sometimes flood a container after opening with dry nitrogen so I can use the rest of the contents rather than throw it out.
I'm not sure if this works, or I'm kidding myself on this one.
I also tend to use the biggest **** driers I can get my hands on on any system I install or service.
Rick - the refrigeration POEs will saturate out at about 1200 to 1500 ppm moisture at room temperature and 70% relative humidity, as opposed to the mineral based oils that saturate at less than 100 ppm moisture. The reason why the POEs hold more moisture is because the oxygen in the ester group is more polar and is happy around other polar molecules like moisture.
The moisture affinity of the POE can be modified by the choice of acids used to make the POE. Short linear acids allow the moisture to 'see' more of the ester group. Longer acid chains will look more like a hydrocarbon oil and will reduce the affinity of the POE for moisture. The use of branched chain acids will also 'hide' the ester group as well as make the POE more resitant to hydrolysis as the mosture has a difficult path to get to the ester.
Most commercial POEs are made from a mixture of acids so that viscosity, miscibility with refrigerants, EP properties and hydroytic stability are balanced. The use of additives to modify the POE properties is not common with the exception of iron passivation using TCP as developed by the military aviation application in the 1950s. The properties of the base POE can usually be tailored to provide good performance without the use of additives that could be depleted in a sealed system where oil changes are not possible.
As molekule has pointed out, the affinty for moisture does not directly lead to corrosion. A lube well below the moisture saturation level will not likely cause corrosion because the water is tied up in solution. Any lube at moisture saturation will likely cause corrosion.
Having personally done testing for packaged POEs in HDPE and metal containers, the metal is a good thing. HDPE wil allow moisture to pass through and the shelf life of the POE will be less than 2 years in average humidity. The metal cans stop moisture ingression completely.
Thanks Rob,
fantastic reply.
From what I understand, one of the major fears with moisture and POE's is the increased quantity of moisture being introduced into a theoretically 'dry' environment will create or revert some of the ester to its acid base, creating havoc with electric motor windings and all the copper/brass utilised in a system.
Even if this moisture is trapped in solution, wouldn't the heat of compression in the compressor 'free' it, if even for a short time to do its dastardly work ?
When moisture has been present in a system, apart from situations such as TX valve orifice freeze up, I've found systems with the ferrous components, particularly valves, with a lovely copper coating.
This was years ago, before POE's were introduced, so wouldn't this be the fear of component manufacturers now, that these scenarios are far more likely to happen ?
Rick.
fantastic reply.
From what I understand, one of the major fears with moisture and POE's is the increased quantity of moisture being introduced into a theoretically 'dry' environment will create or revert some of the ester to its acid base, creating havoc with electric motor windings and all the copper/brass utilised in a system.
Even if this moisture is trapped in solution, wouldn't the heat of compression in the compressor 'free' it, if even for a short time to do its dastardly work ?
When moisture has been present in a system, apart from situations such as TX valve orifice freeze up, I've found systems with the ferrous components, particularly valves, with a lovely copper coating.
This was years ago, before POE's were introduced, so wouldn't this be the fear of component manufacturers now, that these scenarios are far more likely to happen ?
Rick.
"From what I understand, one of the major fears with moisture and POE's is the increased quantity of moisture being introduced into a theoretically 'dry' environment will create or revert some of the ester to its acid base, creating havoc with electric motor windings and all the copper/brass utilised in a system. "
The hydrolysis issue is much overblown in severity and is only rarely seen. The POEs used will not hydroyze unless the discharge temperature of the compressor is abnormally elevated due to a blocked condensor while excess moisture is present. The organic acids generated are weak are not agressive towards metals and electrical insulation materials like the acids generated from chlorinated refrigerant breakdown.
PAG lubricants can cause problems with the PET motor slot insulation material. The PET embrittles over extended times at elevated temperatures and can fail, possibly due to the moisture the PAG carries into the system, but I never saw a definitive mechanism postulated.
"Even if this moisture is trapped in solution, wouldn't the heat of compression in the compressor 'free' it, if even for a short time to do its dastardly work ? "
The solubility of moisture in POE increases as temperature increases. The moisture is in the vapor form at compressor discharge temperatures and is diluted in a large quantity of refrigerant. I have never seen corrosion problems unless the system had free liquid water present.
"When moisture has been present in a system, apart from situations such as TX valve orifice freeze up, I've found systems with the ferrous components, particularly valves, with a lovely copper coating.
This was years ago, before POE's were introduced, so wouldn't this be the fear of component manufacturers now, that these scenarios are far more likely to happen ?"
The copper plating you saw was likely more an effect from refrigerant decomposition. In initial work done with POEs there was a lot of copper plating found in dissected compressors run on HFC refrigerants and POE. The only compressors available at the time were CFC compressors charged with mineral oil, and the compressors were washed out with CFC-11 as a solvent to remove the mineral oil. The residual CFC-11 decomposed with heat and moisture to form strong mineral acids that caused copper plating. When the compressors were washed out with multiple POE flushes to remove the mineral oil, the copper plating magically disappeared.
POEs are much more stable than other ester lubricants like diesters or TMEs. The absence of an alpha hydrogen on the base polyol dramatically increses the thermal stability of the ester.
The hydrolysis issue is much overblown in severity and is only rarely seen. The POEs used will not hydroyze unless the discharge temperature of the compressor is abnormally elevated due to a blocked condensor while excess moisture is present. The organic acids generated are weak are not agressive towards metals and electrical insulation materials like the acids generated from chlorinated refrigerant breakdown.
PAG lubricants can cause problems with the PET motor slot insulation material. The PET embrittles over extended times at elevated temperatures and can fail, possibly due to the moisture the PAG carries into the system, but I never saw a definitive mechanism postulated.
"Even if this moisture is trapped in solution, wouldn't the heat of compression in the compressor 'free' it, if even for a short time to do its dastardly work ? "
The solubility of moisture in POE increases as temperature increases. The moisture is in the vapor form at compressor discharge temperatures and is diluted in a large quantity of refrigerant. I have never seen corrosion problems unless the system had free liquid water present.
"When moisture has been present in a system, apart from situations such as TX valve orifice freeze up, I've found systems with the ferrous components, particularly valves, with a lovely copper coating.
This was years ago, before POE's were introduced, so wouldn't this be the fear of component manufacturers now, that these scenarios are far more likely to happen ?"
The copper plating you saw was likely more an effect from refrigerant decomposition. In initial work done with POEs there was a lot of copper plating found in dissected compressors run on HFC refrigerants and POE. The only compressors available at the time were CFC compressors charged with mineral oil, and the compressors were washed out with CFC-11 as a solvent to remove the mineral oil. The residual CFC-11 decomposed with heat and moisture to form strong mineral acids that caused copper plating. When the compressors were washed out with multiple POE flushes to remove the mineral oil, the copper plating magically disappeared.
POEs are much more stable than other ester lubricants like diesters or TMEs. The absence of an alpha hydrogen on the base polyol dramatically increses the thermal stability of the ester.
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