G100UL - fuel leak

[Immelman]

Keep us posted!

I'm very curious from those of you who use G100UL, and have small seeps, what the outcome is.

Currently I have not yet put any G100UL in (but was planning to). I have a couple of minor weeps that are airworthy, i.e. a couple of rivets with a small amount of staining and a tank panel with a small seep. Could fueling with G100UL make those worse?

[201Mooniac]

26 minutes ago, Will.iam said:

Well if you have run 80 gallons worth of g100ul that would be a significant data point as in your tanks have not started leaking and if you did have a leak to what extent the paint gets removed/destroyed. 

Only about 40 gals so far and the plane is currently in annual so I can't check on it easily but I'm sure if something started weeping the inspection would have called it out.

[GeeBee]

Seems PTE sealant is not compatible nor should it be used. But I bet there are some.

https://g100ul.com/news/gami-review-of-cirrus-service-advisory-sa24-14/

[KSMooniac]

@donkayemight be one of the first Mooney owners with the STC and even had a cameo in the video at GAMI's first CA event a few weeks back.  Perhaps he can contribute a PIREP of his experience so far burning G100UL?

[201Steve]

Not in love with the condition of this bird. I do not mean to sound offensive, but from the limited view, it looks like a maintenance deferred airplane that’s leaking. Not totally shocking, new gas or not. 

[AJ88V]

13 hours ago, GeeBee said:

Seems PTE sealant is not compatible nor should it be used. But I bet there are some.

https://g100ul.com/news/gami-review-of-cirrus-service-advisory-sa24-14/

Wow!  Hadn't thought about it, but at least we Mooney owners don't have to worry about our wings dissolving from this the new UL fuels.  Can you imagine the cost of replacing a wing on your plane?  Ok, the referenced article doesn't actually say anything about the wing structure failing - only the sealant, and that apparently improperly applied - but would you want this stuff in any way contacting your plastic-winged bird?

[donkaye, MCFI]

16 hours ago, KSMooniac said:

@donkayemight be one of the first Mooney owners with the STC and even had a cameo in the video at GAMI's first CA event a few weeks back.  Perhaps he can contribute a PIREP of his experience so far burning G100UL?

The G100UL works great.  It's been mixed with 100LL in my plane, so its benefits won't show up until I use it alone all the time, and that's not anytime soon, since so few airports have it right now.  It does weigh a little more than 100LL at 6.15-6.30 lb/gal.  GAMI says to use 6.25 lb/gal for weight and balance calculations.  The fuel has "slightly higher volumetric density" so has about 1% more energy.  I've found FF to be slightly less at cruise power to get the same TIT.  One thing to be aware of is the necessity to carry an absorbent towel with you when fueling or dumping fuel back into the tank after checking for water.  The fuel will stain the paint if not wiped up immediately.  So far the price is fair at $6.99/gallon.

 

[IvanP]

Good to hear that it is working well for you, Don. Nevertheless, given the propensitiy of the new fuel to damage paint, it would appear that even a minor leak may quickly necessitate reseal of tanks and possibly a paint job. 

[Ibra]

28 minutes ago, IvanP said:

Nevertheless, given the propensitiy of the new fuel to damage paint, it would appear that even a minor leak may quickly necessitate reseal of tanks and possibly a paint job. 

That's my take of it, no leaks: then no problems, if leaking: the paint will take the hit, even with small leaks ! 

Edited December 11, 2024 by Ibra

[redbaron1982]

23 minutes ago, Ibra said:

That's my take of it, no leaks: then no problems, if leaking: the paint will take the hit, even with small leaks ! 

Is there any evidence of this or is it just suppositions?

[DCarlton]

Although there's a lot of speculation here without much data, this thread does make me feel better about the five digit check I wrote for bladders and the big box that was dropped on my doorstep yesterday.   :>  

[Ibra]

10 minutes ago, redbaron1982 said:

Is there any evidence of this or is it just suppositions?

There are lot of evidences that G100UL is not good for aircraft paint

From the horse mouth,

"very small portion of the fuel composition includes a molecule that reacts with ultraviolet (UV) from sunlight and creates the potential for staining"

https://www.g100ul.com/dl/Refueling Hygiene G100UL Avgas.pdf

I would not clean grease/oil on aircraft belly using G100UL and leave to dry under the sun (I am happy to do it with water and 100UL, even for fibreglass or plastic aircraft)

Edited December 11, 2024 by Ibra

[IvanP]

I can see the FBO line guys carrying bottles of Windex and carefully dabbing away thier spills with a clean towel to avoid staining of our planes  . Dream on!

I learned long time ago not to let anyone fuel my plane even before the concenrs about new fuel eating the paint came. 

Edited December 11, 2024 by IvanP

[redbaron1982]

10 minutes ago, Ibra said:

There are lot of evidences that G100UL is not good for aircraft paint

From the horse mouth,

"very small portion of the fuel composition includes a molecule that reacts with ultraviolet (UV) from sunlight and creates the potential for staining"

https://www.g100ul.com/dl/Refueling Hygiene G100UL Avgas.pdf

I would not clean grease/oil on aircraft belly using G100UL and leave to dry under the sun (I am happy to do it with water and 100UL, even for fibreglass or plastic aircraft)

The GAMI article is not clear, as it mentions staining, and it compares it with the blue stains you can get from 100LL.

But it does look like GAMI knows more about what they are sharing, and the staining could be paint damage.

100LL seems to be 100% safe on paint. I have a very small leak on the LH sump for years, it is not dripping or anything, it is just staining. A couple of weeks ago I decided to see if I could clean it up, and all the staining was easily removed, leaving the paint in perfect conditions.

[Ibra]

1 hour ago, redbaron1982 said:

The GAMI article is not clear, as it mentions staining, and it compares it with the blue stains you can get from 100LL.

They are not saying a lot but I recall George mentioning that one should wipe G100UL stains right away (while 100LL stains can wait months or years or until next flight in rain). 

For Mooney with leaking tanks this could be problematic, especially, if it's left outside (with UV exposure)

For Mooneys without leaks, there should be no concerns on paint.

For impact on sealants,  let's "wait and see", I don't think there are any issues? or at least not the kind we will see after one week? maybe decade or 5 years? (at least the fuel inside our tanks does not get lot of UV exposure) 

I wonder if one should have some sort of "UV protection" around fuel caps and fuel drains? also ceramic coating (and hangar) helps 

Edited December 11, 2024 by Ibra

[EricJ]

When I attended George's session at the Buckeye Air Fair this year he said straight out that it is hard on paint, so don't spill it on your paint, and that it may be harsher on seals and gaskets.   I suspected then, and moreso now, that he was underplaying the concerns.   He did flat out say that there were potential issues, though.

So this is at least two aircraft (more if you count the Cirrus) that have sprung leaks or damage after storing G100UL.  Neither is definitive or proof of anything, but I think both warrant concern and keeping a close eye on further developments.    This is the sort of thing you really can't know until field deployment starts, and use still isn't widespread or even enough to get a good sense of what a complete deployment might look like.

 

[EricJ]

1 hour ago, DCarlton said:

Although there's a lot of speculation here without much data, this thread does make me feel better about the five digit check I wrote for bladders and the big box that was dropped on my doorstep yesterday.   :>  

The Baron that leaked had bladders, but they were aging and it is not definitive that the issues were caused by the G100UL.   My personal suspicion is that the G100UL aggravated the aging issues and pushed it over the edge.   That's just an opinion, though.

[KSMooniac]

5 minutes ago, EricJ said:

The Baron that leaked had bladders, but they were aging and it is not definitive that the issues were caused by the G100UL.   My personal suspicion is that the G100UL aggravated the aging issues and pushed it over the edge.   That's just an opinion, though.

One of the many tests they did years ago involved pulling bladders out of salvage yard airplanes that had been sitting outside for years, and then testing them with G100UL.  I've not read any of the technical reports that went to the FAA, but read a lot on Beechtalk over the years about this evolution.  They even got some WWII surplus bladders because the warbird community is very motivated to get rid of the lead as well.  (Imagine cleaning 56 spark plugs per side, as one example!)

[GeeBee]

As to Cirrus. They have been running G100UL for 14 years in a Cirrus wing tank, with no issues.

 

[GeeBee]

13 minutes ago, EricJ said:

 My personal suspicion is that the G100UL aggravated the aging issues and pushed it over the edge. 

That is probably the most sane statement made so far.

 

[AJ88V]

1 hour ago, Ibra said:

I would not clean grease/oil on aircraft belly using G100UL and leave to dry under the sun (I am happy to do it with water and 100UL, even for fibreglass or plastic aircraft)

I know it's common practice to use avgas as a cleaning solvent, but I'm not sure I want the exposure to the lead when other cleaning solvents are available.

Weird but true story - I knew an A&P at the now-closed Hyde Field who would siphon half a gallon of avgas from the tanks and put it in a sprayer to clean down an engine or badly greasy belly.  Besides the likely brain damage from lead exposure, I seriously worried that the entire hangar would blow up some day, say from a spark from the air-compressor motor coming on.  Never happened, but a seriously unsafe practice by any measure.

[Ibra]

28 minutes ago, AJ88V said:

I know it's common practice to use avgas as a cleaning solvent, but I'm not sure I want the exposure to the lead when other cleaning solvents are available.

One barely need more than 50ml to pre-wash a filthy belly (exposures are tiny and are ok while wearing gloves, after all it's not injecting straight in the blood) 

I may pick cleaning solvants but then one gets into all sort of compounds, dosage, chemicals, additives, allergies... avgas is cheap and available, for now 

Edited December 11, 2024 by Ibra

[GeeBee]

Use automotive bug and tar remover for the belly. Cheaper and waaaay safer.

As for lead, as one doctor said to me, anything you touch with your skin is at your liver in 10 minutes.

As to lead exposure, there is a growing body of evidence that adults who were children in the 60's and 70's are showing up with adverse levels of lead which many are saying is part of the growing Alzheimers, dementia and MS rates. Telcom workers and plumbers being the worst.

 

 

[larryb]

This is my plane one week after taking about 15 gallons in each side. The seeps are not new but the result of the seep is stripped paint. I’d be very wary of using this fuel if your tanks are not perfect.

[Igor_U]

Ouch,

We might just use MEK as a fuel; similar results on the paint...