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enter image description hereHi there, I have a 1965 VW Beetle (in Australia) that I am trying to repair. To get it running, it just seems that I just need to repair two holes at the bottom of the fuel tank (it is leaking petrol/gas). Are these holes part of the design (they don't look like the result of damage)? Is there parts associated to filling these holes?

Does anyone know what part I need and how (and where I could get it from Australia) to plug these holes?

Thanks in advance!

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blahdiblah
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Terrence J
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4 Answers4

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Those holes are not meant to be there. This photo of a new tank doesn't have the holes. The holes look like someone has drilled into the tank to remove the fuel at some point. Whether that was to steal the fuel or just to get the fuel out before getting rid of the car.

It probably isn't worth repairing since replacement tanks are readily available, but with suitable safety precautions taken to avoid explosions, it should be possible to braze or solder a patch over the holes.

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HandyHowie
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Back in the day, it used to be possible (in the UK) to wander around a scrapyard and unbolt random bits off stacked piles of dead vehicles, and that was how I kept several cars going.

Fuel tanks though were almost always deliberately punctured by the scrapyard, using something pointy and sharp. Any residual fuel in there would then simply evaporate. There were several safety reasons for this.

  • The fuel system doesn't tend to vent much, so any fuel in the tank stays in there. Ditto fumes.
  • Dead vehicles were usually stacked several high. It's easy to rupture the fuel system (in any number of places) when dropping one car on top of another.
  • People salvaging parts aren't always careful to avoid damaging the fuel system or ensuring leakage of stray fuel is avoided.
  • Even in the absence of other sources of damage, rubber/plastic fuel lines would simply deteriorate and leak.
  • Larger parts were often removed with cutting gear, presenting the risk of heat or sparks to ignite anything combustible.
  • With lights, mirrors and other shiny surfaces, there's a risk of just the sun causing hot spots which would light off anything combustible.

And from a "consumer" point of view,

  • You've no idea whether the tank on a dead vehicle is damaged or not until you fill it up with fuel, which isn't safe.
  • A fuel system exposed to the air will corrode on the inside, causing rust particles to clog up your carbs/injectors.

Generally it wasn't in a scrapyard's interests to open themselves to all these problems. An old screwdriver rammed through the fuel tank solved it fairly quickly and neatly.

Graham
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Are you sure those are the only holes? Looks like at some time there was water in the petrol, and it sank to the bottom (petrol floats) so it rusted away the steel, and someone (you?) has cleaned the rusty edges up. Look for pinholes, perhaps use air pressure and soapy water while blocking all the normal holes.

Welding a fuel tank is not recommended - you'd need to purge and the whole thing with inert gasses or water, but welding near water will make a lot of heat which is steam that interferes with the weld.

The common repair is a 2 part epoxy like JB Weld, which claims to be petrol-resistant. It is hard because you don't have any access to the inside.

I'd go with a thin stainless steel patch, which is completely "glued" to the tank with well-mixed epoxy, and a well-prepared surface on the tank and the patch. Then another layer of epoxy on the outside once the first one has set completely. You might choose to use some fibreglass or other structural cloth as an intermediate layer.

Some people use fibreglass, but it may not be fuel-proof. Check the labels before buying anything.

Your other options are a used tank from a donor car, or a brand-new reproduction tank. Check locally for a VW specialist who can advise.

You might prefer a new plastic or aluminium tank, perhaps with better mounts or more capacity, or more crash-damage resistance.

Criggie
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4

Do not weld gas tanks unless you know what your doing! Its best to solder the holes with a BIG solder iron very hot. I have fixed a lot of tanks. I use copper sheet or copper pennys to solder over the holes. Just use a good flux, any tin/lead solder should do. pre tin the patches and tank. that way you can see if its clean enough for solder to flow over the area. if not, wire brush it and try it again with more flux.

don karry
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