Fuel Tank Reseal - Expensive...

[ArtVandelay]

I've built two sets of tanks for RV's.  Just putting the sealant on properly with unassembled tanks is a PITA.  Would heartily recommend letting professionals handle it.
 

Can you elaborate? What's the problem? Looks like you brush the sealant over all the joints, what's the difficulty?

[markejackson02]

33 minutes ago, teejayevans said:

Can you elaborate? What's the problem? Looks like you brush the sealant over all the joints, what's the difficulty?

The sealant is not toxic or unpleasant, but it is difficult to work with.  It stays on anything it touches.  Need disposable/dedicated clothes, gloves, tools, etc.  It is also time sensitive.  In Houston, you have about 30 minutes to work with a batch before it gets too difficult.  Colder climes have longer working times.

The sealant really needs to be put between parts on the Van's because the flanges are smaller than the Mooney parts.  Then brushed over the seams in a couple coats.  You need to be super careful about which holes to seal, avoid drain holes, etc.

You also have to be careful what kind of tools you use.  For example Harbor Freight brushes tend to disintegrate so you have to use better quality ($$) ones.

And you have to be super careful about cleaning things religiously before applying it.  Soap, then MEK/Acetone and no oily skin contact.

You can certainly do it yourself, but it's not for the faint of heart.

[rbridges]

18 hours ago, Bob_Belville said:

29.7 pounds, I'd rather tell Nancy to leave her purse behind than give up my 20 year old O&N bladders. In fact, after winning some new CiES fuel level sensors at Summit, I'm seriously considering adding the extra 10 gallons now available from Griggs.

 

I've thought about that, too.  64 gallons in a C model.  You'd fly until your other bladder ruptured.  

[Bob_Belville]

1 hour ago, rbridges said:

 

I've thought about that, too.  64 gallons in a C model.  You'd fly until your other bladder ruptured.  

I've been communicating with Chris Murley of Griggs this morning. As soon as I get to talk to Lynn Mace about the installation which seems pretty straightforward I will be ordering the additional bladders. I don't have the STC in hand but I estimate I'll add about 10# to the empty weight of my E. I think I can cut my personal empty weight by that much by the time we do the install. 

Yeah almost 8 hours minus reserves. I'll be stocking up on Travel Johns.

[mike_elliott]

Now all you have to do is stretch it 10" and you will have an F with a smaller UL, Bob! Seriously, that would make a great addition to your plane. BTW, Just scheduled the Bravo to go to Paul Becks for tank reseal. Apparently, the 1999-2000 were the worst of the planes for developing "leaks" Once Paul has at it, it will last 20 or more years for sure. The less than stellar factory job is almost 20. I think this was made in the Dopp brothers tenure, 'nuff said.

 

[Bob_Belville]

14 minutes ago, mike_elliott said:

Now all you have to do is stretch it 10" and you will have an F with a smaller UL, Bob! Seriously, that would make a great addition to your plane. BTW, Just scheduled the Bravo to go to Paul Becks for tank reseal. Apparently, the 1999-2000 were the worst of the planes for developing "leaks" Once Paul has at it, it will last 20 or more years for sure. The less than stellar factory job is almost 20. I think this was made in the Dopp brothers tenure, 'nuff said.

Hi Mike, what do you suppose, does your gullibleness come from your mother's or your father's side of the family?  

(Terry Heim just put bladders in 58N a '68C. He commented on how incredibly strong and well made the O&N/Griggs are. And I know that Lynn Mace has replaced many bladders in brand B and brand P and assures me there's no comparison to the strength of the Mooney bladders.)

My bladders are older than your Bravo and I'm not taking 3RW anywhere to fix any leaks. Just sayin' 

Maybe I could recruit Griggs for a show and tell at Summit-VI.? 

[steingar]

Yeah, I'd like to do the extra tanks too.  Fly the Mooney over the Atlantic. That, and the only time yo have too much gas is when you're on fire.

[mike_elliott]

32 minutes ago, Bob_Belville said:

Hi Mike, what do you suppose, does your gullibleness come from your mother's or your father's side of the family?  

(Terry Heim just put bladders in 58N a '68C. He commented on how incredibly strong and well made the O&N/Griggs are. And I know that Lynn Mace has replaced many bladders in brand B and brand P and assures me there's no comparison to the strength of the Mooney bladders.)

My bladders are older than your Bravo and I'm not taking 3RW anywhere to fix any leaks. Just sayin' 

Maybe I could recruit Griggs for a show and tell at Summit-VI.? 

Bob, we don't want to become a trade show, other venues are for that. WIth that said, we encourage our sponsors to educate us with their technical expertise, such as L3, Bruce Jaeger, Paul Beck and others have done. Maybe they will donate a set of bladders for the silent auction! I certainly would like to know more about the lifespan of bladders, Heck I cant get a rubber band to last more than a year  

I got 34 years on factory sealant on my 1970 F, and yea, it was made during the cost cutting days of Mooney. Perhaps the bladders will last that long too. Who knows? I had Paul reseal the F as their was a real penalty to pay when adding O&N bladders in 2004, that was I had to limit its range with 52 gal vs. 64. And give up 30# of useful for about 3500.00 more than what Paul beck was charging at the time. 

I made the right choice for sure.

The Bravo has 89 gal tanks, bladders are not approved that I know of for it.

 

[Bob_Belville]

1 minute ago, mike_elliott said:

Bob, we don't want to become a trade show, other venues are for that. WIth that said, we encourage our sponsors to educate us with their technical expertise, such as L3, Bruce Jaeger, Paul Beck and others have done. Maybe they will donate a set of bladders for the silent auction! I certainly would like to know more about the lifespan of bladders, Heck I cant get a rubber band to last more than a year  

I got 34 years on factory sealant on my 1970 F, and yea, it was made during the cost cutting days of Mooney. Perhaps the bladders will last that long too. Who knows? I had Paul reseal the F as their was a real penalty to pay when adding O&N bladders in 2004, that was I had to limit its range with 52 gal vs. 64. And give up 30# of useful for about 3500.00 more than what Paul beck was charging at the time. 

I made the right choice for sure.

The Bravo has 89 gal tanks, bladders are not approved that I know of for it.

 

Mike, no, bladders are not an option for any of the long bodies though it is not longer necessary to go from 64 to 54 gallons on Fs, Js, and Ks.

Bladders vs. no bladders have been debated here ad nauseam. In all those threads I do not believe anyone has ever cited a single case of a Mooney whose O&N bladders had to be patched, much less replaced. 

Here's a thought, as our most visible, and justly so, safety proponent, I wonder if you've ever asked any of the experts who crunch accident numbers whether they feel that bladders have or might have a better chance of preventing a post crash fire. 

[mike_elliott]

Just now, Bob_Belville said:

I wonder if you've ever asked any of the experts who crunch accident numbers whether they feel that bladders have or might have a better chance of preventing a post crash fire. 

I have thought about that a lot for obvious reasons. In my case, the wing was snapped off on the pilots' side, and from the pics, sufficient penetration on the copilot's side would have punctured bladders also. Are they better than just aluminum skin for penetration (Gawd, I love that word)? Yes, but how much in their current design?. Now, if they were made like the bladders for race cars, that would be the berries. The fuel cells (note the change of wording from bladders) will withstand a shotgun blast. I doubt this was a design parameter of the O&N's. Again this is something that Grimes data could reveal what their structural strengths are and what they have been tested at if at all. 

I think a bulkhead between the wing (bladders or not) and fuselage would go a long way in post crash fire safety. Fuel will run down the dihedral right under the cockpit, where all kinds of hot things can ignite it.

[Hank]

2 hours ago, mike_elliott said:

I think a bulkhead between the wing (bladders or not) and fuselage would go a long way in post crash fire safety. Fuel will run down the dihedral right under the cockpit, where all kinds of hot things can ignite it.

Can we get an STC for a gull wing, like my favorite warbird the F-4U? All the spilled fuel would run away from the cockpit, unless the plane is upside down . . . . 

[Bob_Belville]

2 hours ago, mike_elliott said:

I have thought about that a lot for obvious reasons. In my case, the wing was snapped off on the pilots' side, and from the pics, sufficient penetration on the copilot's side would have punctured bladders also. Are they better than just aluminum skin for penetration (Gawd, I love that word)? Yes, but how much in their current design?. Now, if they were made like the bladders for race cars, that would be the berries. The fuel cells (note the change of wording from bladders) will withstand a shotgun blast. I doubt this was a design parameter of the O&N's. Again this is something that Grimes data could reveal what their structural strengths are and what they have been tested at if at all. 

I think a bulkhead between the wing (bladders or not) and fuselage would go a long way in post crash fire safety. Fuel will run down the dihedral right under the cockpit, where all kinds of hot things can ignite it.

Yeah, well, I'm pleased to have half a loaf...

[carusoam]

It would be nice to have a piece of aluminum between the cabin and wear the wing gets ripped off.

Best regards,

-a-

[Immelman]

"you can buy an awful lot of patch jobs for the cost of a full strip and re-seal"

- My A&P/IA - a guy who knows his stuff and is not one to gouge me.

[gsxrpilot]

6 hours ago, Immelman said:

"you can buy an awful lot of patch jobs for the cost of a full strip and re-seal"

- My A&P/IA - a guy who knows his stuff and is not one to gouge me.

On the other hand, you can be down for two weeks every six months for another patch job, or get the full reseal and be done for another 20 years.

[Bob_Belville]

15 minutes ago, gsxrpilot said:

On the other hand, you can be down for two weeks every six months for another patch job, or get the full reseal and be done for another 20 years.

@gsxrpilot, @mike_elliott, I think you both refer to 20 years as the life of a reseal. I wonder where that number comes from. Are there data supporting that? How long have WNM, WWT, Houston Tank, others?, been using their current techniques and materials? I've been through the Kerrville facility a couple of times and I note that tank sealant is applied to the mating surfaces before assembly. That obviously cannot be done in a field reseal. 

Inquiring minds want to know... 

[gsxrpilot]

7 minutes ago, Bob_Belville said:

@gsxrpilot, @mike_elliott, I think you both refer to 20 years as the life of a reseal. I wonder where that number comes from. Are there data supporting that? How long have WNM, WWT, Houston Tank, others?, been using their current techniques and materials? I've been through the Kerrville facility a couple of times and I note that tank sealant is applied to the mating surfaces before assembly. That obviously cannot be done in a field reseal. 

Inquiring minds want to know... 

I certainly don't have any hard proof, but I think the general consensus is that the factory new planes are usually good for 20 years or so before needing a reseal and the techniques employed by WNM, WWT, HT, etc. are even better.

[Bob_Belville]

1 minute ago, gsxrpilot said:

I certainly don't have any hard proof, but I think the general consensus is that the factory new planes are usually good for 20 years or so before needing a reseal and the techniques employed by WNM, WWT, HT, etc. are even better.

Yeah, "general consensus", I wonder if 10 years or 30 years wouldn't be just as logical as a SWAG.

[LANCECASPER]

45 minutes ago, Bob_Belville said:

@gsxrpilot\ I've been through the Kerrville facility a couple of times and I note that tank sealant is applied to the mating surfaces before assembly. That obviously cannot be done in a field reseal. 

They started doing that in 2006 at the factory, so all Acclaims would have it and any Ovations 2006 and newer.

Mine was delivered in January 1993, almost 25 years ago. I have had one small patch done by Dugosh when I bought it which I discovered on the pre-buy. They advised against a re-seal and it's worked out well. The right tank has never leaked. I'm the second owner. But the airplane has been hangared since day one, only flown by two pilots. The first owner who ordered it after his 252 was lost in Hurricane Andrew had a lot of Mooney time in three different Mooneys and this one is my 6th Mooney, so it hasn't experienced a lot of rough landings. I think hard landings on weak shock discs is also a contributing factor. Something has to absorb the energy, if it's not the shock discs then it's the airframe.

[Bartman]

I picked up my 1977 bird in 2007. The left tank had already been patched twice beginning at about the 25 year mark and shortly began leaking again after I began flying. We tried to patch the left side one more time but if anything I think it leaked worse so I went with Edison if only because it gave me another reason to go to the beach.

Point is leaks began about 25 years here. 

[N6758N]

Mine is a 68' and there are no entries in the logs for a patch, or a reseal. Not one. I bought the airplane back in 2013 and at the time there were no leaks at all, not even a small weep or any blue stains. Eventually however, the smell of fuel in the cabin became strong, and I started having blue streaks on one or two rivets under the wing. I'd say Mooney did a pretty good job sealing up my wing almost 50 years ago, and I also attribute it to the aircraft always being hangared, flown often, and kept full. I recently put bladders in because, even as an experienced IA, I did not want to tackle the reseal job. 

[mike_elliott]

1 hour ago, Bob_Belville said:

I've been through the Kerrville facility a couple of times and I note that tank sealant is applied to the mating surfaces before assembly.

Not in 1999 per Paul Beck. Thats one of the reasons he said the Dopp era was the worst for the tanks. Today, yes, they are sealing them correctly I am told.

I got 34 years out of my 1970, Bob. A good reseal by Paul should  last much longer using the newer sealants and the care of which he does ea. tank. The issue is one of, just like bladders, the sealant/material deteriorating with age. Heat, just like with bladders, doesn't help the longevity at all. The nice thing about sealed tanks is that we have choices, but lets not start that again...

[EricJ]

11 hours ago, Immelman said:

"you can buy an awful lot of patch jobs for the cost of a full strip and re-seal"

- My A&P/IA - a guy who knows his stuff and is not one to gouge me.

OTOH, my A&P/IA says that once they start needing to be patched it's often an endless chase of repeated patches.

That said, I'm keeping my fingers crossed that the patch that Maxwell did on mine in August is the last leak for a long time.   If not, I'll schedule a trip to Willmar.

[Hank]

4 hours ago, Bob_Belville said:

Yeah, "general consensus", I wonder if 10 years or 30 years wouldn't be just as logical as a SWAG.

When my 1970 tanks were resealed in 2010 or 2011 [I forget, and don't have the logs at work], they had been leaking for a couple of years until they reached the point in the MM that says to do something. When they were stripped, Edison told me that there was evidence of several patch jobs, and that much of the original sealant had the consistency of sand . . . So maybe the 40 years before reseal was a little too long . . .

At any rate,  I should be good to go for a long time now!

[Bob_Belville]

19 minutes ago, Hank said:

When my 1970 tanks were resealed in 2010 or 2011 [I forget, and don't have the logs at work], they had been leaking for a couple of years until they reached the point in the MM that says to do something. When they were stripped, Edison told me that there was evidence of several patch jobs, and that much of the original sealant had the consistency of sand . . . So maybe the 40 years before reseal was a little too long . . .

At any rate,  I should be good to go for a long time now!

Yeah Hank, I'm not going to continue beating this particular glue factory steed but since you're an engineer I'd point out that folks who talk about 20 year mtbf use terms like "should" as in woulda, coulda, shoulda. I'm just a mathematician who practiced Industrial Engineering without a license for a lot of years so those terms remind me of what industry sometimes labels SWAG. 

I'll just add my anecdotal sampling. Lynn patches a pretty high % of the Monneys that come to our little drome. And many of those have been patched several times before, some even by him, hopefully not in the same spot. And some, including a fine '67F based here for many years that had been recently stripped and resealed by one of the specialists at a total cost including redos that would have bought bladders.