Rusty fuel tank

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Author Topic: Rusty fuel tank  (Read 4861 times)

Offline 67FBGT

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Rusty fuel tank
« on: August 17, 2021, 01:22:36 pm »
About 20 yrs ago I bought a '67 FB, as a project, an incomplete car a mate found in California. It wasn't much more than a rolling shell.
I stripped it to bare metal, repaired and repainted it as one does. Over time I collected up all the necessary parts and completed the car.
I had thrown away the original fuel tank as it had some light surface rust inside it and treated the car to a brand new shiny one. Maybe a bad idea in hindsight... :thud:

I started experiencing problems in recent pre-pandemic times, with the fuel sender unit failing, and I thought some kind of fuel starvation was starting to happen. But then the pandemic arrived so I parked the car up as I had far more pressing matters to deal with.
But recently I decided to finally man-up and pull the tank right out to examine it. First I had to drain off nearly 40 litres of by-then possibly stale fuel to gradually use up in my every-day car. I removed the fuel with a suction pump as the drain plug was locked solid.

Finally I got the tank out, and revelations followed. The fuel pick-up and sender unit was badly corroded, not unexpected. What I hadn't expected was that the entire inside of the tank is also rusty. Flaky rusty. All surfaces both up and down. Yet I'd always kept the tank at the very least half full of fuel. WTF?
The exterior has some kind of galvanized finish with a 'Made in Canada' stamp on the top. But peering into the apertures and looking at the welded seams I can see now that the inside faces have no such coating and from the significant rusting must be just bare steel.  :sick:

Anyone else had this issue? Time for me to buy a new tank and a good quality one at that. Advice is always much appreciated.

« Last Edit: August 17, 2021, 01:32:06 pm by 67FBGT »

Offline Dwayne

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Re: Rusty fuel tank
« Reply #1 on: August 17, 2021, 01:46:06 pm »
I'm fitting a BA Falcon fuel assembly into my new tank so will be adding a fuel tank sealer (Por-15 or KBS) to the inside of the tank to protect it from rust.

Offline Dwayne

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Offline AussiePhil

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Re: Rusty fuel tank
« Reply #3 on: August 31, 2021, 06:03:14 pm »
Hey 67,
While you’re doing this work paint your brass float with tank sealer.
There’s another post at the moment about modern fuels eating away brass floats.
I haven’t come across it yet, but I’m using miracle paint at the moment and while my cars not going anywhere I’ll probably add it to the list of jobs!
Cheers Phil
If you've never buggered anything you've never done anything!
But if you've buggered a lot maybe you're not very good at it!

Two for one is good but four for two is better!

Offline 66FBK

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Re: Rusty fuel tank
« Reply #4 on: August 31, 2021, 10:25:42 pm »
The fuel now is bad of older cars with steel lines/tanks and aluminium and brass jet carbys. Never use any fuel with Ethanol . A friend 67 had a repro tank that kept clogging filters with rust and a new holley 600 carby which looked like it was dropped in the ocean for a month with that much corrosion inside. (green brass jets and flaking aluminium inside fuel bowl and accelerator pump rock hard) . This after having it sit for 4 mths. Needed a full carby rebuild and fuel pump. I only use premium and 20L at a time to keep the fuel fresh.
He, with the most toys wins.

Offline AussiePhil

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Re: Rusty fuel tank
« Reply #5 on: September 01, 2021, 06:19:35 am »
Ah, good point Phil! Thanks for reminding me, I do recall seeing a post about it.

That's what I mean about modern fuels. I recall when leaded fuel was phased out in NZ, lots of classic and older cars had problems with fuel lines and carby parts being eaten from the inside by the replacement fuels which varied in composition, some were high in toluene I think they said.
Saw that fuel line degradation on a mate's Mustang. Luckily he spotted it in time, as reportedly some cars caught fire and of course the fuel companies and the insurance companies each blamed the other and didn't want to know.

And if the stuff attacks brass as well...  :thud:  Shock horror...

Hey 67, no problem!
There wouldn’t be any new cars today with metal fuel tanks, no reason for fuel companies to make less aggressive.
Makes you think maybe reproduction fuel tanks made from plastic may be on the way in!
Why not, I’m sure it would be do-able? Great sales pitch, extended life!
Okay for those not wanting concourse cars.
Cheers Phil.
« Last Edit: September 01, 2021, 12:37:21 pm by AussiePhil »
If you've never buggered anything you've never done anything!
But if you've buggered a lot maybe you're not very good at it!

Two for one is good but four for two is better!

Offline 67FBGT

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Re: Rusty fuel tank
« Reply #6 on: September 01, 2021, 07:04:30 pm »
This is my fuel pick-up/sender unit, after 16-17 years immersed in fuel... (The photo doesn't do it justice - it actually looks worse in real life).
No wonder the fuel gauge stopped working some time back...
I note that the float is a plastic of some kind. But the replacement I bought is brass.
« Last Edit: September 01, 2021, 07:07:31 pm by 67FBGT »

Offline AussiePhil

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Re: Rusty fuel tank
« Reply #7 on: September 01, 2021, 07:19:37 pm »
Hey 67,
That’s shocking, but the outside of the tank looks great!
You sure you’re not using dirty water for fuel! :grin:
Do you think it started with the sender turning the tank rusty?
Cheers Phil.
« Last Edit: September 01, 2021, 07:24:57 pm by AussiePhil »
If you've never buggered anything you've never done anything!
But if you've buggered a lot maybe you're not very good at it!

Two for one is good but four for two is better!