G100UL paint testing by YouTuber mluvara

[Shiroyuki]

Someone posted this link on Reddit r/flying, conducted by a concerned aircraft owner. Worth a look.

The video is not marked as not publicly available so only way to watch it is by click the link.

 

[toto]

This is being discussed in G100UL thread #3 over here

https://mooneyspace.com/topic/50230-based-on-the-g100ul-fuel-leak-thread-whats-your-position/

 

[Shiroyuki]

26 minutes ago, toto said:

This is being discussed in G100UL thread #3 over here

https://mooneyspace.com/topic/50230-based-on-the-g100ul-fuel-leak-thread-whats-your-position/

 

Sorry I wasn’t reading all the thread replies. Didn’t know it was already discussed.

However i think this video is significant enough to warrant its own discussion. It clearly shows not only damage to aircraft paint, but o ring seals as well. It is now not surprising this fuel might dissolve or damage Mooney’s tank sealant. It also brings doubt to how compatible it is to fuel lines and fuel bladders…

honestly i find this o-ring issue to be more serious. It is an airworthiness issue now. If the fuel only damages paint, it is still safe to use with caution during fueling and not spill the fuel, and a newly sealed tank that doesn’t leak. But now it also damages seals… and potentially tank sealant, I would not touch this fuel with a 10 ft pole, even after getting my tank resealed.

To add another point, during pre purchase inspection, it was noticed there was some blue stains on underside of both wing. Not a lot, but clearly blue. So i know my tank seeps. I scheduled a time with WeepNoMore right away after closing the purchase. That was March of 2024 and I was informed they were fully booked until June 2026. I still asked them to book me in, because I have no interest in dealing a leaky wing.

So money is only one issue to consider, after G100UL causing leak, when can you get it fixed is another big issue. Over 2 years of wait time is not looking good. I haven’t talk to the other shops in Texas and Florida since Minnesota is just next door to Ontario where I’m located. I recently quote for a new paint from a paint shop in Chiliwack BC, the cost was C$45000 for a full strip and repaint, or USD $30000. That’s a lot of money to rectify damages that could be the result of using G100UL.

[toto]

24 minutes ago, Shiroyuki said:

To add another point, during pre purchase inspection, it was noticed there was some blue stains on underside of both wing. Not a lot, but clearly blue. So i know my tank seeps. I scheduled a time with WeepNoMore right away after closing the purchase. That was March of 2024 and I was informed they were fully booked until June 2026. I still asked them to book me in, because I have no interest in dealing a leaky wing.

No idea what aircraft we’re talking about, but I wouldn’t schedule a tank reseal based on some underwing blue stains. There are lots of different ways to get fuel stains under your wings (leaky fuel sender gasket, leaky fuel sump gasket, etc). If the PPI shows fuel stains, it’s definitely something I would keep an eye on, but I wouldn’t schedule a $10k service based on that. You’ll have plenty of unexpected expenses in your first couple years of ownership. 

[Pinecone]

O-rings out in the open swelling, may not be an issue.

GAMI has tested in a number of planes, over several years.  And if they had identified a problem, it would be really stupid to try to hide it.

Also, a much larger number of planes have been flying with it for a while and no reports of issues.

The paint issue seems to be unique to a leak keeping the area wet all the time.  That might not have come up in testing

[IvanP]

5 hours ago, Pinecone said:

O-rings out in the open swelling, may not be an issue.

GAMI has tested in a number of planes, over several years.  And if they had identified a problem, it would be really stupid to try to hide it.

Yes, it would arguably be unreasonable for a manufacturer to conceal a known problem. However, history is replete with instances where companies had active knowlege of various flaws with their products, yet decided to market the products anyway. In fact, some companuies went to great lengths to hide these flaws. Not saying that GAMI is one of those companies, just that it would not be the first time.  

[201Steve]

5 hours ago, Pinecone said:

And if they had identified a problem, it would be really stupid to try to hide it.

Imagine spending a decade trying to push something through the FAA and then single handedly force it into the market, against all odds, against Pafi, against big oil. If you know the story just a little bit, what he’s overcome, the guy is a certified bad a$$ that is for certain, having gone through all the thorn bushes that he has. 
 

When you have that much heart and soul into seeing it through, it would be realllllll tough to do anything, say anything, that might torpedo the whole initiative if you can manage to minimize the ill effects.  

[0TreeLemur]

7 hours ago, Pinecone said:

The paint issue seems to be unique to a leak keeping the area wet all the time

The person who posted the video believes that under hist test conditions, intermittent wetting and evaporation of G100UL seems to concentrate the component of the fuel that is more aggressive towards paint.   Sadly, that's a Mooney with a leaky tank.

[ragedracer1977]

8 hours ago, Pinecone said:

.

The paint issue seems to be unique to a leak keeping the area wet all the time.  That might not have come up in testing

Posted in a thread here days ago. There’s really only a few scenarios here.  
 

1 - the testing was not as thorough as they thought.

2 - testing was thorough and they knew it might happen, but figured it wouldn’t be a big deal.

3 - there’s something different about the formulation and/or environment in CA that hasn’t been discovered.

In my opinion, a combination of the 3 is most likely.  Maybe higher or lower humidity? Salt in the air or already on panels?  Maybe CA has a slightly different formulation for one of the additives? We know that other entities have stated that G100UL can strip paint.  But it’s been dismissed as “big oil or big money bulls$^t”.  
 

in a very short time, we have empirical evidence that not everything in the below quote is accurate. We’re seeing multiple examples of paint stripping. One of our members (who I know is a very conscientious owner) has seen permanent staining in very little time.

Seeing the swelling of the orings concerns me.  There are a lot of ‘rubber’ products in the fuel system.  I have concerns.  And the answers thus far have not been convincing.  Actually, the non-answers that have been more akin to an attack on the owners of the airplanes.  

“George Braly

Posted December 14

G100UL Avgas is NOT a threat to normal aircraft paint.   We have even soaked a couple of those side panels in G100UL for a week or more.  The paint was fine at the end of that.  

What does and will happen - - is if you do not properly clean up the spilled fuel, and allow it to dry, it can and will leave a light tan stain on the paint.  If you do properly clean it up,  it will not stain the paint - - even after repeated spills in the same location.  But, to date, we have never seen any evidence of any type of "paint striping" activity to any of the dozen or more aircraft parts that were removed from our customers Bonanzas and used as "test articles."”

 

 

[PeteMc]

3 hours ago, IvanP said:

However, history is replete with instances where companies had active knowlege of various flaws with their products, yet decided to market the products anyway.

The tobacco industry comes to mind....

 

[EricJ]

35 minutes ago, PeteMc said:

The tobacco industry comes to mind....

And Boeing.   

...and Ford, and GM, and...

 

[Hank]

1 hour ago, PeteMc said:

The tobacco industry comes to mind....

 

 

57 minutes ago, EricJ said:

And Boeing.   

...and Ford, and GM, and...

 

and Volkswagen . . .

[PeteMc]

3 hours ago, Hank said:

and Volkswagen

I'm afraid to ask.  What VW story and I forgetting about?  And what year(s)?

 

[Wingover]

42 minutes ago, PeteMc said:

I'm afraid to ask.  What VW story and I forgetting about?  And what year(s)?

 

Lying about the CO2 emissions

[Sue Bon]

51 minutes ago, PeteMc said:

I'm afraid to ask.  What VW story and I forgetting about?  And what year(s)?

 

https://www.bbc.com/news/business-34324772

https://en.wikipedia.org/wiki/Volkswagen_emissions_scandal

[Hank]

4 hours ago, PeteMc said:

I'm afraid to ask.  What VW story and I forgetting about?  And what year(s)?

 

 

3 hours ago, Wingover said:

Lying about the CO2 emissions

Actually, they wrote engine control software to detect being in a test cell, and change performance to get good test results. Memory says a college group did road testing of several vehicles and noticed that VW results were much worse on the road than in the test cell.

Cheating is a much worse offense than simply lying.

[Wingover]

And if you want reassurance that companies are there to cheat you.....

https://www.justice.gov/opa/pr/justice-department-announces-largest-health-care-fraud-settlement-its-history

[PeteMc]

@Sue Bon  @Hank   Ah yes, I remember the diesel engine scandal now. 

 

Edited December 25, 2024 by PeteMc

[Pinecone]

On 12/24/2024 at 6:30 PM, IvanP said:

Yes, it would arguably be unreasonable for a manufacturer to conceal a known problem. However, history is replete with instances where companies had active knowlege of various flaws with their products, yet decided to market the products anyway. In fact, some companuies went to great lengths to hide these flaws. Not saying that GAMI is one of those companies, just that it would not be the first time.  

GAMI addressed this.  See post in the long thread.

They state that while the O-rings may swell, there is no adverse effect on their functioning.  In fact, the swelling may help worn O-rings seal better.

When full synthetic oils were introduced in autos, the advice was to not switch to them in an older engine run on dino oil.  The reason was, dino oil contained a small amount of light fractions that caused the seals to swell, and they wore a bit.  If you switched to full synthetic, the seals shrank and leaked.  So the manufactures adding a small bit of light fraction to keep the seals swollen like with dino oil.

[Pinecone]

On 12/24/2024 at 10:06 PM, ragedracer1977 said:

Posted in a thread here days ago. There’s really only a few scenarios here.  
 

1 - the testing was not as thorough as they thought.

2 - testing was thorough and they knew it might happen, but figured it wouldn’t be a big deal.

3 - there’s something different about the formulation and/or environment in CA that hasn’t been discovered.

In my opinion, a combination of the 3 is most likely.  Maybe higher or lower humidity? Salt in the air or already on panels?  Maybe CA has a slightly different formulation for one of the additives? We know that other entities have stated that G100UL can strip paint.  But it’s been dismissed as “big oil or big money bulls$^t”.  
 

in a very short time, we have empirical evidence that not everything in the below quote is accurate. We’re seeing multiple examples of paint stripping. One of our members (who I know is a very conscientious owner) has seen permanent staining in very little time.

Seeing the swelling of the orings concerns me.  There are a lot of ‘rubber’ products in the fuel system.  I have concerns.  And the answers thus far have not been convincing.  Actually, the non-answers that have been more akin to an attack on the owners of the airplanes.  

“George Braly

Posted December 14

G100UL Avgas is NOT a threat to normal aircraft paint.   We have even soaked a couple of those side panels in G100UL for a week or more.  The paint was fine at the end of that.  

What does and will happen - - is if you do not properly clean up the spilled fuel, and allow it to dry, it can and will leave a light tan stain on the paint.  If you do properly clean it up,  it will not stain the paint - - even after repeated spills in the same location.  But, to date, we have never seen any evidence of any type of "paint striping" activity to any of the dozen or more aircraft parts that were removed from our customers Bonanzas and used as "test articles."”

 

The testing in the video looked to cause paint failure at edges or cracks/heavy scratches.  I am wondering if the primer is being attacked.  I know that in the past, auto paint would be 2 part catalyzed, but with a lacquer primer.

And the tested was with the condition of fuel leaking and partially evaporating, but staying wetting with the fuel components that do not evaporate as quickly.

[EricJ]

23 minutes ago, Pinecone said:

GAMI addressed this.  See post in the long thread.

They state that while the O-rings may swell, there is no adverse effect on their functioning.  In fact, the swelling may help worn O-rings seal better.

That's the sort of answer that makes them not a credible source of information on the topic for many of us.   It's like saying you should just put in a larger o-ring than specified to get a better seal.   It doesn't work that way.  

[IvanP]

1 hour ago, Pinecone said:

GAMI addressed this.  See post in the long thread.

They state that while the O-rings may swell, there is no adverse effect on their functioning.  In fact, the swelling may help worn O-rings seal better.

Yes, they "addressed" the issue in similar fashion that big tobacco "addressed" the concerns about nicotine being addictive by saying that it is OK for it to happen. Did they publish any objective and verified data to support this statement?    

Edited December 26, 2024 by IvanP

[MikeOH]

7 hours ago, Pinecone said:

GAMI addressed this.

They state that while the O-rings may swell, there is no adverse effect on their functioning.  In fact, the swelling may help worn O-rings seal better.

BWAAHAHAHAHA!

So, you just take any manufacturer's word when they say, in effect, 'nothing to see here'???  I thought you to be a bit more objective.

And, now swollen seals are a feature/benefit!!  What a revelation...we've all been living in ignorant bliss, I guess.

[GeeBee]

Swelling the O-rings is how Granville Strut Seal works.

 

[Marc_B]

8 hours ago, GeeBee said:

Swelling the O-rings is how Granville Strut Seal works.

Is that how the Mooney fuel system works?