Leaky fuel tank woes ... looking for perspectives

[RobertGary1]

3 hours ago, steingar said:

 

I’ve got 54 gallons in mine, they cost me about 40 lbs, or 6 gallons of avgas, or a suitcase for Mrs. Steingar. I’ve yet to miss the payload.

Or 45 minutes of lost fuel weight in an already tiny fuel capacity tank  

With bladders you convert your cross country machine into a hundred dollar Hamburger short range 172 

 

-Robert

Edited February 13, 2018 by RobertGary1

[ArtVandelay]

Bladders are permanent. If they leak they can be pulled out the holes they were put in and refurbished in situation for about 1 AMU. Joey Cole told me so himself.
My question to the OP is how long will he keep his airplane. That total reseal won’t impress anyone ten or fifteen years down the road. Like I said, bladders are permanent.
I’ve got 54 gallons in mine, they cost me about 40 lbs, or 6 gallons of avgas, or a suitcase for Mrs. Steingar. I’ve yet to miss the payload.

Cost? Especially if OP can do the stripping of the sealant.

[Bob_Belville]

1 hour ago, bluehighwayflyer said:

I have 1000 nm of usable range in my 64 gallon bladder-equipped J at 145 KTAS and 8 GPH.  Our 64 gallon bladder-equipped C will do the same speed at 10 GPH for 800 nm.  Both have 970 pound useful loads.

Even with 54 gallon bladders @steingar‘s C has slightly more range and fuel capacity than any stock B, C, or G model, and considerably more than the entire 172 fleet, including those equipped with 48-50 gallon usable “long range” tanks.  

Jim

Yup, my useful load is 900# (gross in an E is only 2575) and my range with 64 gallon bladders is pretty extraordinary when I need it: over 1000nm, no wind, with ifr reserves (LOP/145ktas/8 gph).

[RobertGary1]

1 hour ago, bluehighwayflyer said:

I have 1000 nm of usable range in my 64 gallon bladder-equipped J at 145 KTAS and 8 GPH.  Our 64 gallon bladder-equipped C will do the same speed at 10 GPH for 800 nm.  Both have 970 pound useful loads.

Even with 54 gallon bladders @steingar‘s C has slightly more range and fuel capacity than any stock B, C, or G model, and considerably more than the entire 172 fleet, including those equipped with 48-50 gallon usable “long range” tanks.  

Jim

But even with the 64 gal bladder system your range is still more limited than a J without bladders. Those bladders cost about an hours worth of fuel weight. That’s an hour of fuel you have to leave in the truck due to the heavy bladders.  That’s the huge downside of bladders. 

 

-Robert

[neilpilot]

3 minutes ago, RobertGary1 said:

But even with the 64 gal bladder system your range is still more limited than a J without bladders. Those bladders cost about an hours worth of fuel weight. That’s an hour of fuel you have to leave in the truck due to the heavy bladders.  That’s the huge downside of bladders. 

You need to understand that RobertGary is a bladder hater, and there's no arguing with him that bladders are a reasonable choice.  His new math makes 45 lb loss of useful load equal to an hour of fuel weight. 

All I know is that my old 64E had bladders, and I loved that final solution to wet wing leaks.  I lost no fuel capacity, and the slight decrease in useful load never was an issue.  Maybe best of all, when my main gear punctured the underside of the right wing after my off field landing, the bladders held a full load of fuel with no leak, and no fire.

[RobertGary1]

16 minutes ago, neilpilot said:

You need to understand that RobertGary is a bladder hater, and there's no arguing with him that bladders are a reasonable choice.  His new math makes 45 lb loss of useful load equal to an hour of fuel weight. 

Just stating the facts. If someone is trying to decide you shouldn’t gloss over a serious downside. 

-Robert

[Bob_Belville]

10 minutes ago, RobertGary1 said:

Just stating the facts. If someone is trying to decide you shouldn’t gloss over a serious downside. 

-Robert

30# (54 gallons) or 40(?)# (64 gallons) is not a "serious downside" in the real world. Quite the opposite, while providing an excellent, practically permanent, solution to leaking tanks, it does not affect the normal mission choices: either fill the seats for 2 or 3 hour legs or fill the tanks for the number of people who are comfortable flying 4-6 hour legs to skip a fuel stop. Only masochists, devoid of modesty, fly over 4 hours with 4 seats full of people.

But this horse has has been beaten to a pump.  

[mike_elliott]

10 minutes ago, Bob_Belville said:

30# (54 gallons) or 40(?)# (64 gallons) is not a "serious downside" in the real world. Quite the opposite, while providing an excellent, practically permanent, solution to leaking tanks, it does not affect the normal mission choices: either fill the seats for 2 or 3 hour legs or fill the tanks for the number of people who are comfortable flying 4-6 hour legs to skip a fuel stop. Only masochists, devoid of modesty, fly over 4 hours with 4 seats full of people.

But this horse has has been beaten to a pump.  

Careful Bob, you are going to start up the peetube hijack

[Mooneymite]

11 hours ago, steingar said:

Bladders are permanent.

Some on Mooneyspace opine that once bladders are installed, one cannot return to the wet-wing configuration.  I spoke with Griggs who has taken over from O&N; he said that a plane could be returned to the wet-wing configuration, but neither he, nor I could figure out why anyone would ever want to do that.

Again....I don't want this thread to devolve into a bladder thread.  The new re-seal processes offered by various vendors do seem to be a good solution.

[Bob_Belville]

9 minutes ago, bluehighwayflyer said:

I understand what you are trying to say, but I don't think you articulating it very well.  Yes, bladders extract a weight penalty that could theoretically be used for fuel instead. We can agree on that. 

 

I know a guy that would choose to take off 40# over gross on a long runway once in great while if the 40# is fuel that he might wish he had a few hours later when he's now 250# below gross.

[steingar]

I still think the biggest thing here is what will the airplane be like down the road?  That's why I ask for the expected duration of ownership.  I think if you go to one of the expensive shops and have a reseal the fix lasts your entire ownership experience.  However, bladders last yours and the next guy's ownership experience, which is why I'm a fan.

I suspect if one just does a patch that one will be chasing this in the future.  It is indeed pennywise if one can do all the work oneself.  That said, there is something I sad in another thread.  There are those who really can wrench on airplanes, and those who think they can.  I wouldn't want to be in the latter category in something on which my life depends.  

[FloridaMan]

 

You'll have to excuse me; I didn't read the thread, but did you check the gaskets where the senders are? 

[Greg Ellis]

You kind of get what you pay for as is life.  After many, many patches to my very old fuel tanks (some patches not lasting one flight!!!)  I bit the bullet and paid for it to be done right.  Took the plane to Paul Beck...you guys have heard of him right?   Photos are before and after.  You can pick which is which.   But Paul's work is like a work of art.

[Immelman]

I thought I would bump this with the --for now-- resolution to my issue...

To cut to the chase: I found the leak, patched it, and its OK for now.

I contacted a couple shops about a full strip and reseal. The most popular one, I was willing to go to but the lead time was just too far out. No one has anything but good to say about the quality of work though, so I may go ahead and schedule a reseal, but it would be far enough out that I had to get the plane fixed with a patch. Another shop, closer to home and known to do these jobs just never wrote back.

My home shop is completely slammed for work (See a trend here?). So what to do? Whereas I worked quite a bit in February, the airline world gives, and the airline world takes... and March turned out to be a very, very easy month. I wish they could all be like this! With the time off, and help from a grandparent with our daughter at home I decided to tackle the leak using Don Maxwell's method. This differed from what my shop had used in the past, as they were not fans of using vacuum on old sealant, but I had decided I didn't have anything to lose with the state of the tank, and Don has a good reputation.

Recall that from the beginning of this thread, my shop had made a couple of patch attempts. In hindsight thinking about the behavior of the tank and where we saw staining, I think we had multiple leaks. Their work as not in vain. It was just that the LAST leak I've been chasing was the worst one.

I broke the work into several half-days' effort so as not to be away from home for to long. It didn't take long to see the leak. I used the plexiglass, mirrors, soapy water, and vacuum per Don's website. The leak was easy to see, coming from the rib in the middle of the tank, near one of the drain holes that lets fuel drain inboard. The fuel must have ran forward along the base of the rub, to the front spar, where it was then visible and worked its way downhill to the wing root, and around the corner into the cabin.

Perhaps the leak was caused from weakness due to AD compliance? The drain holes look like they may have been reamed slightly per an AD in the 1980s and just weakened the sealant a bit.. the holes were missing their factory "top coat" leaving a little weak spot in the bottom of each one.

After locating the leak, I ran quite a bit of water through the tank washing out the soap, scraped back the old sealant, cleaned down to bare metal, ordered the supplies, did the patch per the Mooney manual, and let the plane sit to cure for several days. A few days ago, I transferred my fuel (the other tank was full) (access panels still off), leak tested OK, then transferred the fuel back to the good tank filtering through a chamois per A&P suggestion in case any soap was left. Sealed the panels yet again, and got a final leak check good-to-go from my IA today.

This is a tedious job. It does demand some meticulousness. Don't half-ass it. Clean things thoroughly. Let the gas sit in the tank for a good long time (A couple hours in my case) to accomplish the leak check. They don't always start leaking right away!

I do question the safety of the job. Its difficult to to without your hands and arms contacting avgas, the sealants, and whatever you use as a solvent (Acetone for me), even with many changes of gloves. After opening the tanks a few times now and doing the job though, I can more confidently say that a fuel leak patch is not a scary proposition. Nor an expensive one.

HOWEVER.... after reading here on mooneyspace about several DIY complete reseal jobs I can understand the cost of a complete reseal and believe that when it gets to that point, it will be worth the money to have a professional who warrants the work. Its just too much labor.

 

 

Edited March 24, 2018 by Immelman