Fuel tank fixed (hopefully)

[MrTibbs]

When my fuel light comes on I can put 15 litres (about 3 gallons) in my tank. Any more and it drips out.

As I'm going on a road trip in the next couple of weeks including going over some passes in the Alps and Dolomites where there might not be a petrol station every 20 miles or so I want to be able to fill the tank.

Did a bit of searching on the internet and a product called 'leak fix' by plastic padding seems to be highly recommended (and the manufacturers specifically state it can be used to fix fuel tanks.

So this evening I got to spend 2 hours lying underneath the car taking the strap that holds the tank up off then wire brushing and lightly sanding the rust off. There was an obvious pinhole on the tank (I knew where it'd be as that's the highest point the underseal was bubbling up in).

Put this leak fix stuff on (it cures very quickly) and let it sit for a few minutes.

I've just put 50 litres of water in the tank to check if it holds and there's no drips at all so I'm hoping that can be marked up as a success (unless the petrol disolves the leak fix). I drained the water out of the tank straight after of course and I'll put some fuel in tomorrow or Thursday).

So now it's only double check the tension of the timing belt before putting the filter etc back on, doing a quick home alignment (I put one control arm on slightly out of whack in terms of caster), change the fuel filter, oil and filter, try to get someone to make me new rear brake lines and fit those with cleaned calipers, oh and change the rear seats so they match the fronts and I'm good to go. I only have this week and next, so some late evenings working on the car might be in order.

Mike

[petrolhead611]

I tried that stuff and after pouring in a gallon of fuel into the tank it pi**ed straight out. Thats why I bought the aicraft tank sealant

[MrTibbs]

Hmm, well we'll see if I have any more luck. Did you try it with water and how much sanding etc did you do before slapping it on?

Mike

[John_AZ]

Mike,

If you used this product, it is designed for water leaks and not fuel leaks.
I do not think it will hold.
Plastic Padding Leak Fix - Full Product List Plastic Padding - Henkel

Before I had my tank welded/brazed, I tried a couple of products designed for fuel leaks. None worked and the tank crack was on the top of the tank (usual place).
I used Permatex gas tank sealant that you knead like clay and put on a shiny surface--did not work for long.

GL
John

[MrTibbs]

i'll put some fuel in it tomorrow hopefully to see if it's worked. I'd done a lot of googling about fixing fuel tanks and this came up most often as having worked. It does say it's designed to fix fuel and oil leaks as well. Some folks seem to have had success with it recently enough to have used high ethanol fuel. The proof of the pudding's in filling the tank though. If it holds for 3 weeks i'll be happy. I can get a spare tank sorted after the holiday.

Mike

[MrTibbs]

Just thinking about this, I've tested it with water and it was fine, but it may fail from contact with the fuel.

Petrolhead, how quickly did it fail, was it literally instantly? Also, how large was the hole in your tank. The one in mine is very small (literally smaller than the hole you'd get from a drawing pin.

If it does fail, do you guys think it'd be possible to solder up with electrical solder? Just a thought I had - an electric soldering iron wouldn't generate that much heat and some solder might plug the gap.

Does that sound like a stupid idea?

[John_AZ]

I guess you like to be the "Wild Crazy Guy" that sticks a fork in the electric socket to feel the "tingle"?

The fumes in a tank could explode by a spark. Granted a soldering iron does not create sparks but nothing is impossible.

In Old Mexico, the workers will empty a tank and then throw a burning rag at the fill tube to actually "blow out the fumes" before they work on it.

In the states chemicals are used and usually the entire tank is lifted and put in a solution of water and chemicals-after it fills the tank with the solution ---it is then welded.

But hay!
Give it a try. I am sure others have soldered the tanks and lived.

I want to make it to my 101th birthday.

John

[Dawgz83948]

You guys seem to forget that the tanks expand since fuel vapors pressurize the tank. Hopefully it's flexible sealant.

[MrTibbs]

Yeah, I'm mainly concerned about the risk of a fire. Was thinking an electrical soldering iron might be just hot enough to melt solder but not ignite the fumes. Probably not a great idea.

And no, I'm not into doing stuff that's clearly dangerous just for kicks. Was just wondering whether it's possible to solder up a tiny hole while the tank is still on the car.

[Dawgz83948]

Originally Posted by MrTibbs

Yeah, I'm mainly concerned about the risk of a fire. Was thinking an electrical soldering iron might be just hot enough to melt solder but not ignite the fumes. Probably not a great idea.

And no, I'm not into doing stuff that's clearly dangerous just for kicks. Was just wondering whether it's possible to solder up a tiny hole while the tank is still on the car.

Drain the tank, flush and fill it with water and use a torch to braze it closed.

[petrolhead611]

Hi,
I am familiar with working epoxy resins and fibreglass as have repaired many things before and understand the importance of surface preparation. I cleaned off the tank surface carefully, which revealed several small holes, all bigger than a pin hole-in fact an electical screwdrive blade I was using to scrape crud off the surface went through the metal at one point leaving a highly visible hole. The metal was wire brushed(brass brush so no sparks) thoroughly. I mixed and applied generously, forcing it well into the holes, the Plastic Padding Gas Tank sealant and left it to cure for 24 hours in warm dry(for England) ambient conditions. Poured one gallon of unleaded Esso gas in and it came out almost immediately. Scraping off the Plastic Padding was far more difficult than it had been to remove the previous failed attempts with JB Weld and Permatex Gas Tank Repair, so surface adhesion was not problem. In fact I had repaired the tank over a decade ago succesfully but have forgoten which brand I used,and it when it failed I'd made a subsequent repair with JB Weld which lasted 6 months until went over a huge pothole in a parking lot and obviously the tremendous shaking up loosened the bond. The stuff I've used this time dried to a rubbery consistency.

[Cocacolakidd]

Some do not bother with the steel tanks - most often when there are a few small holes in one spot there are others soon to pop-up in other places.

If the Gas Tank is coming out any way replace it with the later model PLASTIC tank that will not rust/corrode out - There are good used plastic tanks around that are not that expensive.

[Dawgz83948]

Originally Posted by Cocacolakidd

Some do not bother with the steel tanks - most often when there are a few small holes in one spot there are others soon to pop-up in other places.

If the Gas Tank is coming out any way replace it with the later model PLASTIC tank that will not rust/corrode out - There are good used plastic tanks around that are not that expensive.

Except there is a ton of work required to get the plastic tanks in.

[Rasta Monsta]

Originally Posted by John_AZ

I want to make it to my 101th birthday.

John

I am totally buying you a shot. You're almost there, right?

[John_AZ]

Nah, I saw the great pic of you+ on this thread.

924Board.org :: View topic - 2011 PacNW Meetup - THIS WEEKEND!

Maybe a couple years between us

John