Fuel bladders... yes/no ?

[thinwater]

Originally Posted by a64pilot

And then I’d tell your that there are millions of airplanes flying around with bladder tanks, and of course you don’t see many fireballs in the sky.

It all has to do with being completely sealed from the rest of the boat, and I mean of course air tight, think propane locker.
That is I think the challenge.
Why not have custom plastic gas tanks made?
These people will make custom tanks to your drawings.
Triple 'M' Plastics

True. But it's all about the installation details. I've also watched vehicles burn up when a fuel hose chafed through... which is also fabric.

[JPA Cate]

Burn up is mmmmm maybe OK, explode isn't!

Ann

[GordMay]

Originally Posted by a64pilot

And then I’d tell your that there are millions of airplanes flying around with bladder tanks, and of course you don’t see many fireballs in the sky...

It’s difficult to estimate the total number of aircraft, including commercial AND private planes, but (IMHO) safe to say that it’s not “millions” - more like tens of thousands total, and thousands in the air (at any time).

Of course not all of them have bladder fuel tanks.

Otherwise, you point is taken. Fuel bladders can be safe.

Aviation analysts ‘Ascend’ found that the total number of aircraft currently in service, including passenger and cargo, is approximately 23,600. It reckons there are 2,500 more in storage.
➥
But ‘airliners.net’, an aviation enthusiast website, says that there are about 39,000 planes in the world, including all commercial and military planes (but not light aircraft), and that over the course of history, there have been about 150,000.
➥
At any given moment there are about 5,000 commercial airplanes in the sky over the United States.
➥ https://www.smithsonianmag.com/smart...tant-39070996/
FlightAware keep track of all (or at least most) of the aircraft in our skies. And according to them, in the past year there were an average of 9,728 planes, carrying 1,270,406 people, in the sky at any given time.
➥ https://flightaware.com/
When asking the two big air plane manufacturers, Boeing and Airbus, about their expectations for the upcoming years, both are very optimistic. Airbus expects that twenty years from now almost 30,000 air planes will be operating. Boeing predicts, that by the same time, 35,000 planes will be required to fulfil the demand. Compared to the current situation this would mean a doubling in the number of air planes

[a64pilot]

OK, not millions, tens of thousands then.
Does that make a difference?

I find your numbers hard to believe, there are less than 40,000 aircraft in total, yet there are 10,000 in the air at any time?
So at any time 25% of the entire fleet is airborne?

Flight aware by the way only tracks aircraft that are in communication with ATC and have been assigned a squawk. That isn’t a whole lot of little guys.

More I think about those numbers, the more suspect I am of them.
Thrush Aircraft where I worked for years has built about 2,000 Thrush. Airtractor our competitor has built more than 2,000.
So one in ten of every aircraft on Earth were built by one of only two agricultural aircraft manufacturers?
Yes there have been aircraft lost, but not as many as you may think.

Apparently the Cessna 172 is the most produced aircraft there is, that one single model of aircraft, manufactured by one manufacturer exceeds 44,000.

[GordMay]

The numbers, I previously quoted, were noted to be commercial aircraft.


General aviation is defined as all aviation, other than military and scheduled commercial airlines, and includes over 416,000 general aviation aircraft flying worldwide today, ranging from two-seat training aircraft and utility helicopters to intercontinental business jets, of which over 210,000 aircraft are based in the United States and over 140,000 aircraft are based in Europe.
➥ https://gama.aero/wp-content/uploads...ook_forWeb.pdf

More than 90% of the roughly 220,000 civil aircraft registered in the United States are general aviation aircraft.
➥ http://download.aopa.org/hr/Report_o...ion_Trends.pdf

These large numbers of GA aircraft surprised me.
They still don't add up to millions, though (maybe about 1/2 million).

Does it make a difference? Maybe, maybe not; but I always prefer accuracy, over exaggeration (or inaccuracy).

Since Bladders or Fuel Cells are most often used in general aviation aircraft, such as Piper, Beech or Cessna, helicopters, some smaller turboprop aircraft, and unmanned aerial vehicles, I wonder how many " airplanes flying around with bladder tanks" there are?

Otherwise, you point is taken. Fuel bladders can be safe.

[a64pilot]

I’d SWAG that about 30% of GA aircraft may have bladders. Very often the wing is sealed itself and that becomes the tank, and sometimes there are thin aluminum metal tanks placed in the wings.
My little C-140 still has its original 1946 metal tanks that are in excellent condition, but it was originally a fabric covered wing, so it pretty much had to have metal tanks. My Maule has four metal tanks and was a metal wing.
In fact now that I think about it a little, a well made bladder may be safer. It won’t fail at weld seams and or corrode either. Chafing is easily controlled if you think to do so.

GenII Prius I believe has a bladder tank, it’s purpose is to ensure their is no fuel vapor, it collapses like those baby bottles with the plastic bags in them to ensure the baby swallows no air.
Gen III eliminates that,I’m sure to control costs, boost profit.

Bladders aren’t all that uncommon.

Only thing I disliked about them in aircraft is that the floor of one could get a wrinkle in it, and if there is any water in the fuel, it can be trapped behind that wrinkle and not drain out of the fuel tank drain.
We had a C-210L that did that.


I don’t understand why metal fuel tanks in boats don’t last almost forever. They apparently corrode, why is that? Is it from the outside?

[JPA Cate]

From the inside to the out, because of condensation of water in the tank. Wet air comes in through the vent line.

Had a pinhole leak in an aluminum diesel tank on our previous Insatiable. Jim took a bit of epoxy and a bit of a beer can, and the patch held very well.

Ann

[a64pilot]

Originally Posted by JPA Cate

From the inside to the out, because of condensation of water in the tank. Wet air comes in through the vent line.

Had a pinhole leak in an aluminum diesel tank on our previous Insatiable. Jim took a bit of epoxy and a bit of a beer can, and the patch held very well.

Ann

I just got to thinking my 1946 airplane fuel tanks that are I believe about .018 to .020 thousands thick are in excellent condition, but I worry about my 1987 boats tank that is likely 1/8” thick.
I think I understand how and why an aluminum water tank corrodes through, but Diesel fuel is very oily, you would think it would protect the tank?

I know it doesn’t mean there is no water in my fuel, but I’ve never seen a drop in the filter bowl.

[Shane Clarke]

Extremely disappointed in Turtle Pac!

We purchased a 200L inboard yacht tank to replace our primary tank. Followed all instructions including tightening all fittings before installation, even to the point of purchasing the recommended tool for tightening all fittings on the tank and doing this regularly.




All of this to no avail, as the primary fill fitting constantly works itself loose and leaks.




Looking for answers, I contacted Turtle Pac only to be blamed for not tightening the fittings.




Very interesting…




However, this is not the kicker.




It was only then that I was told… The primary issue with the Turtle Pac tanks.




In the event of a leak the tank must be completely emptied and removed from situation, so it can be thoroughly washed inside and out with detergent, then left to dry out for a couple of days.




Failure to do this results in the outer protective layer reacting with the fuel, going brittle and cracking.




The end result, the total failure of the tank. Would have been nice to know that before purchasing…

[Bill Seal]

Check out Fuel Safe bladders. They probably cost an arm, leg, and first born, but they're used in race cars and boats, so you know they're tough. (ever see a Sprint Car flipping down the front straight?)
https://fuelsafe.com/

[Amantha]

Originally Posted by Dave_S

Unleaded not desiel.

I'm thinking of putting in two fuel bladders to replace the plastic outboard tanks and Jerry can refills.

Anyone have issues with bladders ? Maybe grit or a loose screw wearing a hole ?

They will go into separate compartments under the floor on the rear deck. 2x200lt.

Hi Dave,

So I've purchased a few bladders from this Australian company called FLEXIMAKE and so far I haven't had any issues with the bladder. They are pretty reliable and are of high quality. Definitely worth checking em out

https://fmestore.com.au