Based on the G100UL fuel leak thread what's your position?

[EricJ]

16 minutes ago, ragedracer1977 said:

I don’t think you understand the scientific method.

It’s in this thread. There’s 2 videos, both using a very clear scientific method, showing paint damaged by G100UL.  There’s photos from multiple aircraft taken at different locations by different people, including the AOPA.

I like that Mr Luvara gave more of his credentials this time.    Some of us mentioned before that his previous tests looked very nicely done and well-controlled.   He's an engineer and a pilot and an A&P and has quite a bit of experience in the field.   I don't think there's any reason to think the tests weren't done competently.    They look reliable to me (also an EE and pilot and A&P).

https://www.linkedin.com/in/mike-luvara-828531/

 

[PT20J]

I was a bit skeptical of the first video, but I'm actually impressed by the quality of the second video. This guy's like Jack Smith: He read posts by his critics on MS and other sites and took pains to address them in his discussion of his observations and methods and carefully makes his case. Some may not like his conclusions but I cannot fault his approach or methodology. I would like to see GAMI repeat his tests as he performed them. Others should also. If the results are repeatable then we will know something.

[MikeOH]

I found Mr. Luvara to be quite careful and scientific with his experimental methodology.  I, too, hope that @George Braly would want GAMI to repeat Mr. Luvara's methodology and present the results.

[Kelpro999]

1 hour ago, gabez said:

but you won't because ultimately you trust our experience, videos and pic more than GAMI's

 At this time I agree. After presenting questions of age and evaporation a while back , I was met with stories of old fuel in sealed containers performing like new fuel… completely dodging my concerns.

 I’ve spent most of my life dealing with failed seals, paints and sealants. After watching both videos I won’t be filling with G100UL anytime soon. 

  

[Aaviationist]

7 hours ago, LANCECASPER said:

You have to come up with at least three more screen names before you're entitled to proof . .lol

Not sure what your accusation is but this is the only profile and name I have ever posted under, other than for 5 minutes when I had to generate a new one because a bunch of insecure, paranoid cry babies didn’t like something I wrote. 

[Z W]

5 hours ago, PT20J said:

I was a bit skeptical of the first video, but I'm actually impressed by the quality of the second video. 

Agreed. Definitely a basis for more testing to see if his results can be duplicated, and a reason for concern.

[GeeBee]

The solution is for AOPA and EAA to pool resources, supply some field airplanes and hire an independent lab to do the tests. The AOPA Baron is nice, but not enough. If ever there was a reason for the two organizations to exist, this is it. They might however end up like the CDC during Ebola and Covid and simply spit out the bit.

[Aaviationist]

7 hours ago, ragedracer1977 said:

I don’t think you understand the scientific method.

It’s in this thread. There’s 2 videos, both using a very clear scientific method, showing paint damaged by G100UL.  There’s photos from multiple aircraft taken at different locations by different people, including the AOPA.

There’s really only two options.

#1: G100UL can strip paint and may have an adverse effect on fuel system components and materials.

#2: this is just another part of a vast conspiracy to “silence” G100UL.

 There is no in between.

That’s not how the scientific method works. We’ve seen the same test with different results. 

there is no conclusion to be had here and further research and testing needs to be done.  Not just the same inconclusive test repeated.

Apparently I’m the only one who passed my 8th grade science class. 

Edited 19 hours ago by Aaviationist

[T. Peterson]

2 hours ago, Aaviationist said:

That’s not how the scientific method works. We’ve seen the same test with different results. 

there is no conclusion to be had here and further research and testing needs to be done.  Not just the same inconclusive test repeated.

Apparently I’m the only one who passed my 8th grade science class. 

Can you not just make your case without insulting people? Lots of folks on this forum disagree with me, but that doesn’t upset me. I try to persuade, but not to belittle. You can actually respect and appreciate people with whom you disagree.

[philiplane]

2 hours ago, Aaviationist said:

That’s not how the scientific method works. We’ve seen the same test with different results. 

there is no conclusion to be had here and further research and testing needs to be done.  Not just the same inconclusive test repeated.

Apparently I’m the only one who passed my 8th grade science class. 

For what it's worth, fuels are not tested to be compatible with paint. They're not expected to be routinely applied to painted surfaces. 

Also, the test videos shown do not specify what paint systems were used on the parts. This is a critical part of testing. 

As for rubber components in the fuel storage and distribution system, it seems obvious that more testing is needed to identify and develop solutions to any potential G100UL compatibility issues.

[A64Pilot]

11 hours ago, philiplane said:

Catalyzed paints (2-part polyurethane, acrylic urethane, or acrylic enamel topcoats like Acryglo, Imron, etc ) are normally immune to even the worst solvents. However, most primers are sensitive to lacquer thinner, and enamel reducers, which include toluene and xylene. My bet is that the paint damage shown started with the primer coats. With the primer corrupted, the top coat goes along with it. 

I think you’re probably correct, my experience with Jet-Glo is that it’s impervious to almost anything. It may be the primer that’s failing. 

But it doesn’t fail with 100 LL, and in the end does it matter? I’ve never seen UL Avgas, but whatever I have to use I’d prefer if it didn’t turn my old aging paint brown, cause it to bubble up and come off, whether it’s the primer or paint the end result is the same.

My concern would be what’s happening to the rest of my fuel system, my bladders which by the way are made from the same material as normal O-rings that we know it causes to swell, and the other components that I cannot change like the seals and diaphragm in my fuel pumps, fuel flow sending unit, and my fuel pressure transducer, my Servo and divider and I’m sure there are other things I’m missing. It’s not O-rings that concern me.

It may be that decades of sitting immersed in 100 LL has weakened these polymers and that if everything is new the Gami fuel is fine, but I can’t replace everything

Who knows, but my opinion is that I’d avoid this fuel until we know for sure if it’s going to be problematic or not, give it a year or so at least.

Edited 16 hours ago by A64Pilot

[gabez]

2 minutes ago, philiplane said:

For what it's worth, fuels are not tested to be compatible with paint. They're not expected to be routinely applied to painted surfaces. 

Also, the test videos shown do not specify what paint systems were used on the parts. This is a critical part of testing. 

As for rubber components in the fuel storage and distribution system, it seems obvious that more testing is needed to identify and develop solutions to any potential G100UL compatibility issues.

maybe so but what's your position on the advertisement on the GAMI website as well as the STC for the engine and STC for the airframe. Should we have interpreted those as: the effect of G100 on the paint is the operator responsibility? because if so I don't think it was clear. 
 

[Schllc]

The reality is that limited testing is great, and helps to establish a baseline, but more expansive testing with aircraft is definitely prudent prior to making this a mandate anywhere. 

Whether it is testing by Gami, or by allowing the market willing to put the fuel in their planes and see what happens, but one way or another there needs to be broader use to observe the effects over the myriad permutations of aircraft configurations.

That is the scientific way to do this, but again, people should have the option to participate, not have it forced on them.  

In spite of the invective and hostility that peppers this thread, the root of the argument is not whether GAMI is bad or evil, but what methodology is appropriate to introduce this to the aviation market.  It does not seem fair, safe or even realistic at this juncture, to say that it is ready to supplant 100LL across the fleet.

[PT20J]

3 hours ago, Aaviationist said:

That’s not how the scientific method works. We’ve seen the same test with different results. 

But it wasn’t the same test. In one, the fuel was allowed to evaporate on the surface and the reapplied repeatedly simulating a seeping fuel tank. In the other, the painted part was continuously soaked in fuel. This difference might explain the different results. More investigation seems warranted.

[Aaviationist]

38 minutes ago, philiplane said:

For what it's worth, fuels are not tested to be compatible with paint. They're not expected to be routinely applied to painted surfaces. 

Also, the test videos shown do not specify what paint systems were used on the parts. This is a critical part of testing. 

As for rubber components in the fuel storage and distribution system, it seems obvious that more testing is needed to identify and develop solutions to any potential G100UL compatibility issues.

Exactly. 

if you want to test this scientifically you need to know the exact materials and methods used at the factory, and in the field in the case of repainting. 
 

you need to test ALL of those options separately (materials AND methods) with a control and each variable. 
 

you need to log the data reliably and at specified intervals. 
 

What you don’t do is throw a bunch of objects using unknown methods of unknown origins in a bowl and then go “oh look! See what it did!”  - that’s what we have here. 
 

George came the closest and provided the most data. 
 

Testing is based on properly maintained machines, fuel tanks, and materials. 

[Marc_B]

Do we even know if extensive testing on paint was even performed by GAMI??  Mr. Braly stated that paint was never a test criteria for PAFI and the "tests" he shared wasn't an assortment of paints and preparations reflective of the fleet. 

Mr. Braly's interpretation of his own testing was that having an item half submerged and half outside of G100UL gives the air/fluid interface an area where fuel is wicked up the surface (through surface tension) and the volatile component is allowed to evaporate.

BUT, I think this is like me taking  a candle and quickly moving it across my hand...it doesn't burn if it moves fast enough and only damages the surface when it stays in an area for a prolonged time.  I find it interesting that there is still a decent amount of residual liquid left in the containers when new fuel is no longer added...I think there may be a measurable amount of less volatile components in G100UL and it may be when these are concentrated through evaporation + have an extended dwell time = damage is seen.

Mr. Braly mentioned that the testing GAMI performed was boundary testing, i.e. identifying the harshest condition and if fuel passes that test then it is extrapolated to pass testing on less harsh conditions.  But if testing parameter didn't include extensive paint testing by design, you don't "see" what you didn't see.

As an aside...to those who feel that the paint testing done by Mr. Luvara isn't reflective of "real world."  Keep in mind that most fuel engine testing is high power 150 hr block testing used to extrapolate effects of usual varied power, low power cruise, etc over the lifetime/TBO.  Subject it to simulated "harsh" conditions for a shorter time to simulate longer period of less harsh conditions. 

The testing format shown by Mr. Luvara looks like a good replication of what we'd see in actual use of a fuel...simulating an exposure to partially evaporated/evaporated fuel continually over time.  It also may more accurately reflect spillage of fuel by the fuel vent, a slowly leaking fuel sump drain, fuel that splashes up repeatedly from hitting a flapper valve during fueling that isn't immediately cleaned up...even if you do a great job cleaning up a spill, there are parts of the wing that fuel can seep into with a splash that may have primer only covering...wing spar, speed brake areas, inner wing skins and all the things the inside of the wing contains

So I don't think this is "just a cosmetic" argument.

Paint isn't just done to make aircraft "pretty"...it's a protective covering that helps delay/prevent corrosion which is a detrimental force with every aircraft.

[Andy95W]

I’m really hoping that George Braly and GAMI can find a formulation that definitively doesn't affect paint or sealant and that still meets the detonation margins required for our engines.  There seems to be a wide range of allowable percentages of the individual chemical components, perhaps they could even stay within the existing patent and STC.

I hope they succeed. The mere fact that other companies with huge resources such as Shell tried and failed makes me cheer for the success of a “little guy” like GAMI.

[Marc_B]

As an aside, for those with an environmental concern (for example)...was any testing done to see if an alternative fuel burns dirtier than 100LL?  Aromatic amines are pretty nasty healthwise and aromatic hydrocarbons burn dirty (it's why you see so much soot in the cylinders and tailpipe of aircraft running G100UL.  How do exhaust byproducts compare between G100UL and 100LL??

The ultimate issue is "Where do you stop with the environment?"  Aircraft don't typically have mufflers, don't typically have catalytic converters, and nationally burn tons of Jet A annually that's pretty dirty (go check out an airport parking lot and see what covers all the cars in parking).

[Marc_B]

1 hour ago, Andy95W said:

There seems to be a wide range of allowable percentages of the individual chemical components, perhaps they could even stay within the existing patent and STC.

Use Google patents to look up one of GAMI patents...it's pretty interesting to read more about how this was made and what was tested. 

Some components have much different properties with different isomers of the compound that vary greatly, and some components are added solely to help "buffer" an otherwise negative effect.

i.e. from GAMI's patent: p-toluidine has octane enhancing properties, but high melting point of +44C compared to m-toluidine melting point of -30C, and o-toluidine has undesirable toxicity issues.  Typically toluidine produced in ratios roughly 60% o-, 36% p-, and 4% m-toluidine.  Looks like quite a bit of testing with co-solvents was used to find a way to use toluidine as an octane booster while not having clouding of the fuel with low temperatures.

Xylenes comprise up to 45% by weight; aromatic amines up to 6% (according to 2020 patent).

[Andy95W]

8 minutes ago, Marc_B said:

As an aside for those with an environmental concern...was any testing done to see if an alternative fuel burns dirtier than 100LL? 

Aircraft don't typically have mufflers, don't typically have catalytic converters, and nationally burn tons of Jet A annually that's pretty dirty (go check out an airport parking lot and see what covers all the cars in parking).

I suspect these comments here on MooneySpace are preaching to the choir.  Other than a pro forma “any lead is bad” argument, nobody here has really voiced these issues.

Your post would be incredibly important presented to Congress or the public, where I’d bet these facts would go absolutely nowhere. Think about it- if one small airplane crashes, people are in an uproar about safety.  Meanwhile, every year over 40,000 people die on the highways, most due to drunk driving, but nobody pays any attention.

[Marc_B]

6 minutes ago, Andy95W said:

I suspect these comments here on MooneySpace are preaching to the choir.

My comment was intended to point out that important things aren't always tested.  If the PAFI criteria didn't mandate exhaust or paint testing, it doesn't mean that these aren't "important", but just that they weren't the "focus."

[redbaron1982]

37 minutes ago, Marc_B said:

As an aside for those with an environmental concern...was any testing done to see if an alternative fuel burns dirtier than 100LL?  Aromatic amines are pretty nasty healthwise and aromatic hydrocarbons burn dirty (it's why you see so much soot in the cylinders and tailpipe of aircraft running G100UL.  How do exhaust byproducts compare between G100UL and 100LL??

The ultimate issue is "Where do you stop with the environment?"  Aircraft don't typically have mufflers, don't typically have catalytic converters, and nationally burn tons of Jet A annually that's pretty dirty (go check out an airport parking lot and see what covers all the cars in parking).

It reminds me of one of the finding from AOPA G100UL test: heavy dark deposits on the exhaust and spark plug. GAMI dismissed that as "they go away if blown, so nothing important", but what about the environment?

[Schllc]

1 hour ago, Aaviationist said:

Exactly. 

if you want to test this scientifically you need to know the exact materials and methods used at the factory, and in the field in the case of repainting. 
 

you need to test ALL of those options separately (materials AND methods) with a control and each variable. 
 

you need to log the data reliably and at specified intervals. 
 

What you don’t do is throw a bunch of objects using unknown methods of unknown origins in a bowl and then go “oh look! See what it did!”  - that’s what we have here. 
 

George came the closest and provided the most data. 
 

Testing is based on properly maintained machines, fuel tanks, and materials. 

Well, actually throwing "everything in a bowl, and see what happens", is pretty much what has to happen, but obviously in a more controlled fashion.  Testing the fuel in a sample as small as they used, with relative homogenous configurations, is too small a sample set to be conclusive either.

There are entirely too many permutations of components and materials for either test to be considered "conclusive".  But what is evident is that there is potential for damage predicated on a varied history of repairs and materials.  Some may not be approved, but some likely are and the only way to find out is to test more widely.  

It is safe to say that IF (I stress the if because I do not want to impugn GAMI in any way) there are any dangerous interactions with the formulation of G100UL, this is not a disqualifier, merely and indicator of what needs to be inspected, qualified and or changed on an airframe to make it safe.  

While the proper way to get to the point where this is an actual drop in replacement may be broad and varied, we can say rather conclusively, for the sake of safety, that the one wrong method we have identified, is to force it on the entire fleet at this point in time.

[gabez]

Quick Update: The FAA investigators are at KWVI and asked permission to collect samples from my plane (which I gave) those included oil. 

More to come 

[dzeleski]

I've refrained from commenting up until this point...

The fact that this company thinks "testing" painted services by throwing a few panels into aluminum pans as a sufficient test and then even worse declares that there are no adverse effects to the paint from that test is pretty alarming to me. The complete lack of ownership of the problem is even more concerning.

The second part of the testing video done by mluvara is enough for me to never put this fuel into my airplane under any circumstances. There is a clear chemistry issue here and the responses from said company are not positive. The fact that these orings are swelling so bad that you cannot re assemble these components is a real issue.

We know that many of same solvents that attack paint also attack our fuel sealant. When this fuel sloshes around in our tank it is very possible that it is leaving behind whatever the same compound is that is attacking these painted surfaces. Seeing that reddit post with the push rod is seriously worrying.

I would love to see someone test samples of CS3204, CS3600, and CS3330, both submerged and with splashes of fuel since that is the conditions our tanks regularly see. If I had easy access to the fuel I would try it myself considering I have left over of all 3 sitting in my hangar about to expire.

I very much want an unleaded fuel, lead is not good for us and its terrible for our engines. I would love to be able to use synthetic oil and extend our change intervals as well as have an engine that runs cleaner. But the results of what is happening in the wild with this fuel is not acceptable. Hopefully this is a chemistry problem that can be resolved, but that requires ownership and acknowledgement of the problem to begin with.

Im looking forward to what VP and Swift come up with, more specifically VP considering I have ran hundreds of gallons of their various race fuels over the years.

Thats my .02 on this situation.

TL;DR: This fuel will never go inside my airplane as its chemistry presently sits.

Edited 11 hours ago by dzeleski