G100UL thread MIA?

[gabez]

1 hour ago, George Braly said:

 

First:  We (GAMI) had nothing to do with the deletion of the thread.    I was as surprised as everyone else. 

However, let me repeat something posted in the deleted thread:

We have soaked painted aircraft parts in G100UL avgas for extended periods.  The paint remained fully intact without any visual evidence of any degradation. 

I am a bit time constrained with ongoing certification work - -  but when I get time - - I will try to find some pictures.

So - - how to explain the difference in the results on the bottom of the wing of the Mooney?  

The paint on the parts removed from the Bonanzas was no more than about 20 years old.  But it was in visibly good condition.

Before and after soaking.   

The surrounding paint on the bottom of the Mooney wing ?   You can evaluate that for yourself. 

George  

 

thanks for pointing out I don't have the best painted plane on the lot....however in the 3 years I owned it and used 100LL I never experienced a problem with the paint peeling. The paint is original from 1984. this happened in the span of 1 week, 80 gallons and 3 trips. I will not be convinced the fuel has nothing to do with it. 

 

I have no problem with sending fuel samples, paint samples what ever you need. the plane is at KWVI

Edited December 17 by gabez

[larryb]

Have you thought of dripping fuel on painted surfaces for an extended amount of time? Perhaps something in the air is making the difference vs soaking the part. Or perhaps variations in the evaporation rates are causing the concentrations of the chemicals to change?

[varlajo]

1 hour ago, larryb said:

Have you thought of dripping fuel on painted surfaces for an extended amount of time? Perhaps something in the air is making the difference vs soaking the part. Or perhaps variations in the evaporation rates are causing the concentrations of the chemicals to change?

Yes, good point, I will most likely use some of the fuel sample to brush a painted panel every couple of days - in addition to submersion testing. 

[MikeOH]

7 hours ago, George Braly said:

 

First:  We (GAMI) had nothing to do with the deletion of the thread.    I was as surprised as everyone else. 

However, let me repeat something posted in the deleted thread:

We have soaked painted aircraft parts in G100UL avgas for extended periods.  The paint remained fully intact without any visual evidence of any degradation. 

I am a bit time constrained with ongoing certification work - -  but when I get time - - I will try to find some pictures.

So - - how to explain the difference in the results on the bottom of the wing of the Mooney?  

The paint on the parts removed from the Bonanzas was no more than about 20 years old.  But it was in visibly good condition.

Before and after soaking.   

The surrounding paint on the bottom of the Mooney wing ?   You can evaluate that for yourself. 

George  

 

What different paint types have you tested?

 I have no idea of the different paints used over the years but I suspect an old alkyd enamel wouldn’t fair as well as a catalytic polyurethane (e.g. Imron)

[1980Mooney]

On 12/16/2024 at 8:03 PM, IvanP said:

Well, it seems that the decision will be airplanes in 1915 were considered rich man’s toys,made for us by the government(s). The bureaucrats do not give a s^%$ about what it will cost us….There have been more than few "new and improved" things that were forced onto the public that would not survive on the open market if it were not for government mandates or subsidies.  

“There have been more than few "new and improved" things that were forced onto the public that would not survive on the open market if it were not for government mandates or subsidies.”

Hmmmm…. Let’s think of one!

AVIATION  -   Its adoption and growth over the past 100 years 

The federal government has been subsidizing aviation since the first air mail contracts in 1918.  They built most of the runways in this country during World War II.  Few general aviation airports are able to support themselves financially alone and operating losses are generally subsidized by city budgets. Capital spinning is subsidized by federal grants ( which, if not directly to an airport are dolled out to state aviation agencies, which in turn  subsidize local airports) The successful private airports are usually the first ones to succumb to sale to developers for new housing  (I’ve seen three airports disappear in West Houston to become housing during the past 25 years).  General Aviation isn’t paying its way for ATC either – it’s subsidized by commercial operators.  

So maybe now bureaucrats will start giving a s^%$ about how much they are subsidizing us and maybe we will actually be required to start paying our way. Let’s see how long we survive.

Edited December 20 by 1980Mooney

[MikeOH]

I’m surprised I need to point this out, but there is an enormous cavern of a distinction between a government subsidizing an activity that they wish to encourage and promote, and one which they force upon their citizens! Kalifornia appears to be following the later path in regards to piston aviation fuel.

[Fly Boomer]

5 hours ago, IvanP said:

Perhaps the forum moderator could shed some light on who and why deleted the original thread. 

See above.

[KSMooniac]

A question for the owners of the Mooneys with suddenly failing tanks and paint... do you know if/when the tanks were last re-sealed, or are they original?  Any known repairs in the logs, or visible with some inspection?

I don't have a dog in the fight (yet) but anticipate we will all be switching fuels before we're done flying, unless you plan to hang it up in the next year or two.  We (Mooney universe) need to figure out what is happening before there is a massive fleet-wide issue.

To those concerned that all of the data and cheerleading for G100UL is coming from GAMI, that is half-true.  Don't forget that G100UL got CERTIFIED by the FAA, so they were/are a party to all of the testing that was required throughout the process.  That data is not public, however, but let's not pretend that GAMI is simply pushing it out into the world with no independent verification.  It was a very long and arduous process, and far more extensive than what 100LL went through before it came on the market.  

That universe of testing included tanks, bladders, wet wings, metals, composites, etc. to show that it would not harm the airframes, or more importantly perhaps, dislodge particles that could foul the fuel system and lead to a loss of power.  I believe GAMI (and the FAA) looked at as many common sealants and bladder materials, both new and old, to prove no harm.  Perhaps George will shed more light eventually with the details.  He has been extremely forthcoming and transparent at OSH and on Beechtalk over the years so I don't believe anything is being purposely hidden.  The 12? year process with FAA should have covered all of the bases.

However, what cannot be 100% covered is every combination of repairs that deviate from manuals and material specs, and that is what I would like to uncover with these early failures.... We all know that Mooney wings eventually leak, and any number of A&Ps (or owners) over the years have tried to patch or repair and might have done so with who-knows-what materials.  I've seen enough pics and heard stories from Maxwell and others when they end up having to fix someone else's handiwork.  There is a non-zero chance that some incompatible repair material has been applied over failing OEM sealant, and G100UL might attack it to the point it accelerates a failure and maybe even turns into a witches-brew of chemicals that also attack paint on the way to the ground.  Let's dig deeper and get the data on these cases before we call this a complete failure.

(It is possible we're uncovering a real issue.... I know the FAA certified Mobil 1 oil a few decades ago and that destroyed a lot of engines.  But I doubt this issue will be even remotely close to that one.  Hopefully)

[larryb]

Mine is a factory original 1997 Encore. Factory tank sealant and factory paint. I don’t know that I have any sealant issues, just the paint issue.

[T. Peterson]

1 hour ago, 1980Mooney said:

“There have been more than few "new and improved" things that were forced onto the public that would not survive on the open market if it were not for government mandates or subsidies.”

Hmmmm…. Let’s think of one!

AVIATION  -   Its adoption and growth over the past 100 years 

The federal government has been subsidizing aviation since the first air mail contracts in 1918.  They built most of the runways in this country during World War II.  Few general aviation airports are able to support themselves. 
operating losses are generally subsidized by city budgets. Capital spinning is subsidized by federal grants ( which, if not directly to an airport are dolled out to state aviation agencies, which in turn  subsidize local airports) l.  
successful private airports are usually the first ones to succumb to developer new housing  (I’ve seen three airports disappear in West Houston to become housing during the past 25 years).  General Aviation isn’t paying its way for ATC either – it’s subsidized by commercial operators.  

So maybe now bureaucrats will start giving a s^%$ about how much they are subsidizing us and maybe we will actually be required to start paying our way. Let’s see how long we survive.

I do wonder why the government has subsidized aviation for 100 years. If there is no value to the country or the economy I certainly don’t think it fair for the taxpayer to be saddled with taxes to allow a few airplane enthusiasts to pursue their favorite hobby at the expense of the less fortunate. If that is indeed the case then let the federal/state funding cease. Let the General Aviation airports that can’t sustain themselves close. Let the excess airplanes be turned into soup cans, and all the mechanics and parts suppliers move onto something else. Garmin, Avidyne et al can concentrate on Airliners. No need to certify satellite based approaches at hundreds of airports.
But, if perchance, the benefit to everyone is worth the subsidy, then the subsidization argument as it relates to the fuel mandate is invalid. I am not arguing that GA is worth the cost to the taxpayer. I truly don’t know, but if not, then all the subsidies should stop and this fuel debacle will be a moot point. If GA is worthy of the subsidies then the fuel debate continues based on many different factors, but the subsidization of aviation for 100 years is not one of them.

[gabez]

4 hours ago, KSMooniac said:

A question for the owners of the Mooneys with suddenly failing tanks and paint... do you know if/when the tanks were last re-sealed, or are they original?  Any known repairs in the logs, or visible with some inspection?

I don't have a dog in the fight (yet) but anticipate we will all be switching fuels before we're done flying, unless you plan to hang it up in the next year or two.  We (Mooney universe) need to figure out what is happening before there is a massive fleet-wide issue.

To those concerned that all of the data and cheerleading for G100UL is coming from GAMI, that is half-true.  Don't forget that G100UL got CERTIFIED by the FAA, so they were/are a party to all of the testing that was required throughout the process.  That data is not public, however, but let's not pretend that GAMI is simply pushing it out into the world with no independent verification.  It was a very long and arduous process, and far more extensive than what 100LL went through before it came on the market.  

That universe of testing included tanks, bladders, wet wings, metals, composites, etc. to show that it would not harm the airframes, or more importantly perhaps, dislodge particles that could foul the fuel system and lead to a loss of power.  I believe GAMI (and the FAA) looked at as many common sealants and bladder materials, both new and old, to prove no harm.  Perhaps George will shed more light eventually with the details.  He has been extremely forthcoming and transparent at OSH and on Beechtalk over the years so I don't believe anything is being purposely hidden.  The 12? year process with FAA should have covered all of the bases.

However, what cannot be 100% covered is every combination of repairs that deviate from manuals and material specs, and that is what I would like to uncover with these early failures.... We all know that Mooney wings eventually leak, and any number of A&Ps (or owners) over the years have tried to patch or repair and might have done so with who-knows-what materials.  I've seen enough pics and heard stories from Maxwell and others when they end up having to fix someone else's handiwork.  There is a non-zero chance that some incompatible repair material has been applied over failing OEM sealant, and G100UL might attack it to the point it accelerates a failure and maybe even turns into a witches-brew of chemicals that also attack paint on the way to the ground.  Let's dig deeper and get the data on these cases before we call this a complete failure.

(It is possible we're uncovering a real issue.... I know the FAA certified Mobil 1 oil a few decades ago and that destroyed a lot of engines.  But I doubt this issue will be even remotely close to that one.  Hopefully)

most of my tanks are original we did open up some panels to reposition the aux fuel sump valve....you can see my threads about that. The work was done in may of 2024 (this year) and I hadn't had a problem since. I may have said this before but maybe I didn't. this is a 2 part issues:
1. has the fuel gone through the sealant. or was just a coincidence. I would love to be the latter trust me
2. the damage to my paint is not age or weather related, it's definitely chemical

My plan of action stands, I am not pointing any fingers, I am making sure the community is aware of my problem, we will meticulously attack the problem and keep GAMI involved. I offered to send them fuel and paint, I am just not paying for shipping. Once we have all the facts we will go from there. They have the name of the shop and I don't need to be in the middle. It's better to have one plane grounded and dealing with one squeaky wheel than 100s grounded and off we go to the races.  






 

Edited December 18 by gabez

[Z W]

Anybody yet had a G100UL leak that did not cause any paint damage?  It would be good if they would post here if so, along with when the plane was last painted, and whether the leak was present before introducing the new fuel.

Given the rate my plane develops leaks from the sumps (even new ones, until cleared), and other fuel tank leaks, it'll only be a short matter of time. I suspect planes with any kind of modern chemistry paint will be fine. Though it will be a real shame if vintage paint jobs suffer damage.

I also think letting 100LL seep for extended periods damages paint. I had a pesky leak around a fuel sump rivet that took a while to get fixed, and even after cleaning it up, the paint is visibly stained/damaged in that area, although not stripped off.

I wonder if paint damaged by a long-term 100LL leak, being exposed to a new chemistry fuel (G100UL), could finish the job and cause the paint to bubble off. That would be the real test and may be hard to duplicate in a lab setting.

A note - Highly recommend Oyltite fuel tank sealant for seeping rivets. Seems to work about as well when applied externally to the rivet head as trying to get a shop to seal the leak from the inside of the tank.

[Pinecone]

20 hours ago, IvanP said:

Most of the data that we have appears to be from a single source - the purveyor of the fuel. Don't interpret my concerns as a resistance to adoption of new fuel. I am all for improvement, but I also want some reasonable assurances, other than those made by the manufcaturer or government, that the change will not have signifcant adverse impact on safety and utility of my aircaft. In the ideal world, the market forces would determine the outcome, i.e, if the new fuel is better and safer than what we have, pilots will cheerfully adopt it and 100LL will go the way of the rotary telephone. I do not recall that the old phones were banned or that the govt would madate adoption of smartphones (by Apple or othewise). The market forces simply worked in favor of better products and consumer safety was not affected in any way (not getting into the theories of cellphones causing brain cancer here  ).    

When it comes to fuel, the logistical issues with adoption of new products are much more complicated and thus it is more than likely that some form of government mandate will replace the current fuel and there will be little, if any, choice the consumer can make. Hence, I believe that the safety of the replacement product in such crcumstances needs to be tested with much greater scrutiny before it is unilaterally forced upon the public. While I aplaud George Braly and his team for developing the new fuel and I do not mean to imply in any way that his claims are false or unfounded, I am somewhat reluctant to blindly accept the claims without independent verification. The old proverb "Trust, but verify" comes to mind here.     

Except that does not always work.  BetaMax was a much better technology than VHS, but VHS won the market.

Unleaded auto gas is better in many ways for cars, but it took the government to mandate conditions that make it required.  FYI, Amoco sold unleaded auto fuel for many years before it was required.

One of the issues is whether the benefits are obvious enough.  With 100UL, most pilots will simply look at the price per gallon and not use it.  Ignoring that it can double oil changer intervals (Lycoming already has an SB to do this), increase plug life, provide higher supercharge rating octane (only a factor for warbirds), etc.  

Also, unless there is some mandates, very few fields can or will support two fuels. 

[EricJ]

3 hours ago, Z W said:

I also think letting 100LL seep for extended periods damages paint. I had a pesky leak around a fuel sump rivet that took a while to get fixed, and even after cleaning it up, the paint is visibly stained/damaged in that area, although not stripped off.

Those are nearly always surface stains that can be removed with sufficient treatment, polish, etc.    Once they're on long enough to turn brown they're definitely harder to remove, but should still be removable.

[Vance Harral]

31 minutes ago, EricJ said:

Those are nearly always surface stains that can be removed with sufficient treatment, polish, etc. 

In my experience that's not always practical.  It's one thing to aggressively polish down a flat surface like a wing skin.  Quite another if the stain has seeped into lap joints, non-flush rivets, and so forth.  In those locations, you're likely not getting rid of the blue/brown stains without taking a wire brush down to bare metal and repainting a touch-up area.  A combination of laziness and interest in preserving the protective value of the paint even if it looks awful, has left us with a number of blue/brown stains on the undersides of the wings.

I'm watching these threads with great interest.  We've been getting by with tolerating small seeps and making every-few-years patches on our original (1976) sealant.  That got us through the ~20 years since we bought the airplane, and I don't regret the approach one bit.  But the collection of small annoyances and increasing concern about getting to a patch facility in the event of a major breach, has led us to schedule our airplane with Don Maxwell for a full strip and reseal at the beginning of February.  I'd like to think this is going to give us "new" sealant that's relatively impervious to whatever fuel achieves market leader status in the future, but time will tell.  It's hard for me to worry about the paint for now, as the current paint job was not that great on day one (in 1990), and now has 35 years of wear-and-tear.  G100UL is sort of a moot point for us in the near future, as there is none nearby: only 100LL at our home drome , and UL94 that we can't use at some other Colorado airports.

[IvanP]

2 hours ago, Pinecone said:

Except that does not always work.  BetaMax was a much better technology than VHS, but VHS won the market.

Also, unless there is some mandates, very few fields can or will support two fuels. 

Nothing is perfect, including the free market competition. The VHS v. BetaMax battle was decided by marketing strategies and not by a government mandate, though. I cannot judge which of the two techmologies you mentionwed was better, but I am willing to bet that neither forced their respective users to pay tens of thousands of dollars in repairs. Contrast that with madating a fleet-wide use of fuel that could potentially adversely affect airworthiness of many aricraft without having sufficient data.

Again., I am not saying that G100UL is causing the problems described by some users, but I woud like to see some transparency about the testing process and results. Maybe the FAA has the data, maybe GAMI had tests done by independent agent. Transparency will help to address the concerns. I agree that it woudl be impractical to have two piston fuels.

Your point about price is valid. If most pilots do make their decision based only on price as you aserted, we can test this theory by making UL fuel cheaper than LL and see how it goes  . I sincerely believe that UL fuels should and will be the future, I just do not want to have this to cause problems for us by mandating something that has not been sufficiently tested and proven safe.    

[201Mooniac]

Maybe I missed something but where is the mandate?  Yes, RHV isn't selling 100LL, hasn't been for 2 years now and while I'm based there I haven't been told I have to buy anything, I've been buying fuel elsewhere.  AFAIK, the California government has not banned 100LL, there is a court case brought by environmental groups that led to an agreement that when unleaded fuel was avail;able, FBOs would stop selling 100LL.

Obviously this is not to say there won't be a government mandate but I haven't seen one yet.  Please let me know if I missed it, I'd like to read about it.

[MikeOH]

3 minutes ago, 201Mooniac said:

.... there is a court case brought by environmental groups that led to an agreement that when unleaded fuel was available, FBOs would stop selling 100LL.

I don't know about other posters, but that is the 'mandate' I'm referring to.  I believe the term used is 'commercially available' which is rather undefined.  The concern is that other airports may now view G100UL as 'commercially available' and be pressured by that environmental agreement/ruling to stop selling 100LL.  Not sure how it will play out.

[201Mooniac]

5 minutes ago, MikeOH said:

I don't know about other posters, but that is the 'mandate' I'm referring to.  I believe the term used is 'commercially available' which is rather undefined.  The concern is that other airports may now view G100UL as 'commercially available' and be pressured by that environmental agreement/ruling to stop selling 100LL.  Not sure how it will play out.

Mike, thanks for clarifying.  I guess I was referring to the comments that implied (at least to me) that the government was forcing this and I hadn't seen that.  I agree that 100LL will go away in California if not other places, it is a matter of when, and I think that is generally a good thing.  I agree the fuel should not cause damage when used and to me at least I would say a fuel that caused damage was not commercially viable and therefore not commercially available but that is just my opinion which is worth exactly nothing.  Just as the court agreement was driven by a lawsuit, it can be held off by one to clarify the commercial availability if people want to push back.

[IvanP]

48 minutes ago, 201Mooniac said:

Maybe I missed something but where is the mandate?  Yes, RHV isn't selling 100LL, hasn't been for 2 years now and while I'm based there I haven't been told I have to buy anything, I've been buying fuel elsewhere.  AFAIK, the California government has not banned 100LL, there is a court case brought by environmental groups that led to an agreement that when unleaded fuel was avail;able, FBOs would stop selling 100LL.

Obviously this is not to say there won't be a government mandate but I haven't seen one yet.  Please let me know if I missed it, I'd like to read about it.

Here is your mandate, albeit in its inverse form, i.e., a ban on the only currently widely available aviation fuel for pistion engines.  California SB 1193 adds provision to Public Utilities code banning sale of leaded aviation fuel as of 2031. You may notice that any requirement for safe replacement fuel is conspicuously absent from the bill. 

https://leginfo.legislature.ca.gov/faces/billCompareClient.xhtml?bill_id=202320240SB1193&showamends=false  

Other states, and possibly feds will likely jump on this bandwagon. I believe that the ban is being challenged, but it is probably a losing fight. 

Edited December 18 by IvanP

[PT20J]

Transitions are never completely smooth. We got the lead out of mogas decades ago. We will get the lead out of avgas. Lead is bad for people and engines. Getting rid of it eliminates an argument against GA used by groups that just don’t like little airplanes. 

[Igor_U]

Is it just me or the original thread just got deleted again?

[gabez]

34 minutes ago, Igor_U said:

Is it just me or the original thread just got deleted again?

Again I did not delete the thread and also changed my password as the admin suggested. so ...... 

[redbaron1982]

37 minutes ago, Igor_U said:

Is it just me or the original thread just got deleted again?

This is a shit show... like everything around ____UL (as in anything unleaded fuel related)

Edited December 18 by redbaron1982

[GeeBee]

With regard to applying sealant before assembly and riveting Mooney did that in later models then abandoned the method. As it was explained to me by WetWingolists, to do this assembly method requires precision riveting. This is because simply "gooping" the pieces and riveting results in the sealant being pushed out or being too thin. There has to be a precise gap for the sealant to reside within. Simply put, the Mooney factory did not have such precision equipment nor was it economical to purchase such equipment so they returned to the old method. I am told they paid for a lot of reseals using the old method on these aircraft.