G100UL - fuel leak

[Marc_B]

On 12/15/2024 at 12:04 PM, George Braly said:

With respect the discussion about the high levels of toluene and aromatics sometimes found in 100LL,  see the attachment, which is a "DHA"  (Detailed Hydrocarbon Analysis)  using a standard ASTM test method, that was run at the reference fuel laboratory (Dixie Services, Deer Park, Tx) from a sample pulled from our local FBO 100LL, supplied by rail from the Phillips refinery in Borger Texas.

This sample from 2010 seems like an outlier.  Do you have a current sample of 100LL compared with a current sample of G100UL?  Thanks for helping to understand this!

[Fly Boomer]

1 minute ago, Marc_B said:

This sample from 2010 seems like an outlier.

Have you seen other samples that would demonstrate that it's a outlier?

[Marc_B]

1 hour ago, Fly Boomer said:

Have you seen other samples that would demonstrate that it's a outlier?

Outlier compared to (google search for "100LL SDS") of the SDS for 100LL from a variety of manufacturers...

EDIT FOR CLARITY: I didn't find one that had 29% toluene.  Most showed <10-15%.

This was the SDS source I showed the picture from (Phillips 66 SDS):

https://www.aviation-fuel.com/pdfs/MSDS_for_AvGas_100LL_from_P66_dated_3-04-13.pdf

 

 

[Fly Boomer]

Just now, Marc_B said:

Outlier compared to ANY of the SDS for 100LL from a variety of manufacturers...

 

I'd like to see those if you know where to find them.

[George Braly]

>>As an aside, is it even established that it's Toluene that's causing damage to sealant/paint?<<

For the 100LLs produced up until the last few years,  it was common for them to have as much as 29% toluene and then another 3 or 4% other aromatics for a total around 33% aromatic content.  The vast majority of that was simple paint store toluene. 

The last 100LL sample I had analyzed by DHA at the lab was a decade ago.  I have posted that analysis.  Can do that again.

But, yes, it is the toluene that did that for 100LL.   

Some of the 100LL only had about 15% toluene, but from the refineries with lower quality aviation alkylate - - they used increasing toluene to provide the octane they needed. 

Xylenes are a related molecule, but less aggressive chemically - - according to the retired refinery - expert chemist retained by the FAA in 2012 to do an independent evaluation of the G100UL avgas fuel chemistry. 

George

[Fly Boomer]

2 minutes ago, Fly Boomer said:

I'd like to see those if you know where to find them.

I found one that shows identical concentration:

https://www.aviation-fuel.com/pdfs/MSDS_for_AvGas_100LL_from_P66_dated_3-04-13.pdf

[George Braly]

Here is a modest proposal:

If the Mooney folks would like to learn more,  GAMI will offer to host a "Mooney Delegation" here at Ada.  

Maybe anywhere from 3 to six participants ? 

I will print out all of the material compatibility test data that the FAA has approved and we can sit down around a conference room and review that.   I will answer any questions.   

In the process you can get a chance to see the engine test cell and maybe have an opportunity to observe while it is run on G100UL vs 100LL vs "other"  PAFI/EAGLE type fuel chemistries. 

There may be some additional items of interest. 

Let me know? 

[Fly Boomer]

10 minutes ago, Marc_B said:

Outlier compared to ANY of the SDS for 100LL from a variety of manufacturers...

 

Here is another more recent SDS that shows substantially higher concentrations:

https://www.epc.shell.com/DocumentManagement/BlobDocumentDownload?DocId=119466305

 

[Fly Boomer]

16 minutes ago, Marc_B said:

Outlier compared to ANY of the SDS for 100LL from a variety of manufacturers...

 

Here is a third one from ExxonMobile that shows a wide range, but the upper end of the range appears to be higher:

https://www.msdsdigital.com/system/files/Avgas 100LL.pdf

[Fly Boomer]

20 minutes ago, Marc_B said:

Outlier compared to ANY of the SDS for 100LL from a variety of manufacturers...

 

Here is a fourth from Chevron that shows a wide range, but the upper limit is higher.  I don't see the one George showed as misrepresenting the toluene in 100LL from a variety of manufacturers:

https://cglapps.chevron.com/sdspds/SDSDetailPage.aspx?docDataId=431702&docFormat=PDF

[Marc_B]

1 hour ago, George Braly said:

If the Mooney folks would like to learn more,  GAMI will offer to host a "Mooney Delegation" here at Ada. 

Mr. Braly, I'm sure that many of us (and probably more than 6) would love to learn more and see the shop in Ada!  I always had the Advanced Pilot Seminar on my bucket list and I think it used to be held in Ada?

56 minutes ago, Fly Boomer said:

Here is a fourth from Chevron that shows a wide range, but the upper limit is higher.  I don't see the one George showed as misrepresenting the toluene in 100LL from a variety of manufacturers:

My comments shouldn't be seen as inflammatory and certainly didn't have that intent.  The SDS sheets I saw mentioned <10% toluene; @Fly Boomer you found one with <15% and <20% and the sample Braly shows from 2010 has 29%.  That's still is a decent difference.  I'm aware that there are variations from manufacturers and even from batches.  G100UL SDS shows up to 40% xylene and up to 5% toluene.  But how accurate are SDS and do they reflect product at the pump??

A single fuel sample from 2010 doesn't really help understand a comparison for composition of G100UL and 100LL; especially if current fuels aren't reflective of that sample.  And certainly doesn't help to understand what happened to the tank in this thread and if it has anything to do with G100UL.

[Marc_B]

41 minutes ago, Fly Boomer said:

I don't see the one George showed as misrepresenting the toluene in 100LL from a variety of manufacturers:

That wasn't what I'm implying.  Rather, does this sample from 2010 reflect the 100LL we're currently using and does it reflect the averages that the 100LL fleet used?  I'm not a chemist.  Just trying to learn more about the products we use.

From ASTM D910:

X1.8.1 Aromatics Content—Low boiling aromatics, which are common constituents of aviation gasolines, are known to affect elastomers to a greater extent than other components in aviation gasoline. Although Specification D910 does not include an explicit maximum aromatic limit, other specification limits effectively restrict the aromatic content of aviation gasolines. Benzene is virtually excluded by the maximum freezing point of −58°C, while other aromatics are limited by the minimum heating value and the maximum distillation end point. Thus, the heating value limits toluene to about 24 %.
Xylenes have a slightly higher heating value and, therefore, would permit somewhat higher aromatic concentrations; however, their boiling points (above 138°C) limit their inclusion at levels not higher than 10 %. Total aromatic levels above 25 % in aviation gasoline are, therefore, extremely unlikely.

 

[gabez]

13 hours ago, Shiroyuki said:

 

We all know mooney’s tank will leak eventually because of poor design choice, however that doesn’t mean it is ok for G100UL to shorten a sealants life span.

if some old sealant works fine with 100LL and suddenly starts leaking with G100UL, that’s a problem, and owners deserve to be warned about it before using the fuel.

A slightly weeping wing may last another five or ten years on 100LL, and if switching G100UL kills it in three month, don’t blame it on Mooney or the fuel tank.

And tbh this whole argument is not about old deteriorating sealant, it’s about g100ul making otherwise not leaking old sealant leak…. Same for the paint…

we need a clear answer if the fuel hurts sealant and paint rather then simply blaming it on old paint and old sealant. Also due to conflict of interest I’d like to see test results from third party lab…

this whole thread is going nowhere with one side blaming mooney’s tank design, old sealant, and some plane’s old paint.

I agree 100% given I am the one with the issue. I think if they would have made stronger and more conservative disclaimers it would have raised more awareness. It is also advertised as having 2-3% more power and therefore you will see less fuel consumption relatively speaking. on 3 flights it was 13.1-13.3 all the way, same as 100LL. It also smells awful not that 100LL is roses but damn......

[T. Peterson]

Maybe we will someday get an STC for an engine that burns Jet A????

[Shiroyuki]

1 hour ago, T. Peterson said:

Maybe we will someday get an STC for an engine that burns Jet A????

aren't most diesel engine fairly heavy? That already short engine mount now have to bend backward to make a turbodiesel fit in WB....

[Marc_B]

Out of curiosity, can anyone say what the aromatic content amounts are in the California G100UL?

[Fly Boomer]

6 hours ago, Marc_B said:

G100UL SDS shows up to 40% xylene and up to 5% toluene.

It's late in the day for me, and I'm too lazy to go back through all these posts, but I had it in my head that toluene was the bad one with regard to paint, so 5% is lower than the max for most of those 100LL SDS reports.  I thought George was suggesting that UL might not be as hard on paint as LL based on the toluene percentage?  This stuff is giving me a headache.  Maybe tomorrow.

[Pinecone]

On 12/18/2024 at 10:01 AM, MikeOH said:

Let me put this another way: If it was some Big Oil company C-suite suit that was promoting G100UL would you be such a Kool-Aid drinking fan-boy?  I doubt it.

Telling me you know George or the Big Oil guy in the suit is NOT a compelling argument.

It's not a matter of if George, or anyone else, is out to harm anyone in GA or their aircraft (I don't believe he or anyone else is).  The ISSUE is two-fold: You cannot test EVERY possible situation (your words), and it is being FORCED upon us (e.g. RHV banning 100LL since G100UL is 'commercially available').

G100UL needs to be present in the FIELD for an extended period of time (several years, IMHO) alongside 100LL BEFORE 100LL is removed from the market.

IOW, I want to see some field beta testing by willing participants like yourself BEFORE I start using the fuel.  If it is an acceptable substitute the market will make it successful.

HOW is it supposed to be in the field and available?  And USED by pilots.

Please explain how that can occur.

I would be more than happy to test G100UL.  And it is not a beta, test, that level has been done. 

[MikeOH]

16 minutes ago, Pinecone said:

HOW is it supposed to be in the field and available?  And USED by pilots.

Please explain how that can occur.

I would be more than happy to test G100UL.  And it is not a beta, test, that level has been done. 

What part of "G100UL needs to be in the field...alongside 100LL BEFORE 100LL is removed from the market" is so incomprehensible?  This is NOT complicated: have a truck with G100UL available at airports alongside existing 100LL tanks/pumps.  Don't just BAN 100LL and bring in G100UL (e.g. RHV).

And, no, it has NOT been beta tested IMHO.  How many planes have run G100UL, and for how many hours each?  NOT nearly enough to take away 100LL and FORCE me to use G100UL.

I'm glad you and, hopefully, MANY others will USE G100UL to prove it's actually an acceptable substitute.  Then ban the 100LL and FORCE me to pay more per gallon.

[T. Peterson]

2 hours ago, Shiroyuki said:

aren't most diesel engine fairly heavy? That already short engine mount now have to bend backward to make a turbodiesel fit in WB....

I am no engineer, but Diamond makes it work. The Wright brothers claimed commercial aviation would never happen due to the inherent limitations of weight vs lift. I am just hoping for another so-called impossibility to be rendered not only possible, but practicable. I would love to see the avgas debate rendered obsolete by a series of engines using something else. At least we could argue about something different for awhile.

[wombat]

8 hours ago, Shiroyuki said:

 

... that doesn’t mean it is ok for G100UL to shorten a sealants life span. ...

I somewhat disagree with you on this.   Just because a new product has some flaws that old products didn't or performs more poorly than an old product did in some aspect that doesn't mean the new product isn't better or isn't worth switching to.

If sealants last 99.5% as long with G100UL as they did with 100LL, that's probably a worthwhile trade-off.  (average of 58 days shorter life span of 30 years)  If it's 10% as long as with 100UL, it's probably not worth it.

Now I'd love new products that have no regressions whatsoever but that's rarely the case.

[PT20J]

1 hour ago, MikeOH said:

What part of "G100UL needs to be in the field...alongside 100LL BEFORE 100LL is removed from the market" is so incomprehensible?  This is NOT complicated: have a truck with G100UL available at airports alongside existing 100LL tanks/pumps.  Don't just BAN 100LL and bring in G100UL (e.g. RHV).

And, no, it has NOT been beta tested IMHO.  How many planes have run G100UL, and for how many hours each?  NOT nearly enough to take away 100LL and FORCE me to use G100UL.

I'm glad you and, hopefully, MANY others will USE G100UL to prove it's actually an acceptable substitute.  Then ban the 100LL and FORCE me to pay more per gallon.

Here's what I don't comprehend:  How many FBOs have an extra tank for a second fuel? How many would pay to install one for the few years that we have two fuels available? If there were two available and the G100UL is more expensive, how many owners would pay the premium? If G100UL cuts into 100LL sales, how many refineries would stop producing it? Ditto with the one company that still makes TEL. 

[MikeOH]

3 minutes ago, PT20J said:

Here's what I don't comprehend:  How many FBOs have an extra tank for a second fuel? How many would pay to install one for the few years that we have two fuels available? If there were two available and the G100UL is more expensive, how many owners would pay the premium? If G100UL cuts into 100LL sales, how many refineries would stop producing it? Ditto with the one company that still makes TEL. 

The solution is to use trucks for the G100UL.  I'm NOT onboard with paying more for G100UL and will continue to use 100LL for as long as it is available at lower cost.  If G100UL cuts into sales of 100LL sufficiently that refineries stop producing then so be it; at least I'll be forced to buy due to market forces NOT government mandate!  Hopefully, by then, G100UL will be sufficiently vetted that my concerns over valve wear, tank leaks, and paint damage will have been proven false.

[jetdriven]

The distribution and sale of G100UL is going to run into a brick wall because all the oil companies have exclusive marketing agreements with FBO's and they can only sell their branded fuel.

[Shiroyuki]

2 hours ago, T. Peterson said:

I am no engineer, but Diamond makes it work. The Wright brothers claimed commercial aviation would never happen due to the inherent limitations of weight vs lift. I am just hoping for another so-called impossibility to be rendered not only possible, but practicable. I would love to see the avgas debate rendered obsolete by a series of engines using something else. At least we could argue about something different for awhile.

Diamond Da42 and da50 are clean sheet design intended to use diesel engine.

i guess if someone really want to do it they can surely slap another 100lbs ballast in the back. But then you will lose even more useful load as long body Mooney already don’t have much UL.