Fuel tank

[Number 7]

Hi all,
well having dropped the diff. out yesterday to replace the broken diff. beam, I thought I'd have a general look around for anything else needing attention. I could see that there was evidence of a very slight leak around the outlet on the o/s tank of the pipe which connects the two tanks (the one at the top, not the larger dia. one at the bottom). The pipe looked past it's prime anyway, so that came off, but I can now see that it's the metal outlet pipe itself that is very slightly loose in the tank. I can't say the prospect of dropping the tank out, flushing, welding/brazing etc. etc. appeals, so does anyone know whether there is any sort of sealant product that could be applied around the joint to cure the leak with the tank in situ?

TIA.

7.

Looks like Hermetite do a two part epoxy putty repair kit specifically for tanks - anyone used this stuff?

>> Edited by Number 7 on Wednesday 21st September 17:39

[shpub]

Yep... Didn't work... It's remove tank, flush and repair time. Please Please be careful as even flushing them doesn't always work and they can go bang big time. Worth getting a specialist to do it IMHO.

[tallbloke]

Running exhaust gases through a tank for 20 mins will make it safe to weld. The Carbon monoxide reduces the volatile gases to render the tank non-flammable. Make sure you don't use a car which back-fires to do this though.

[redwedge5]

Same problem found when my car was having the diff beam replaced, but it was the nearside tank! Tank had to be removed, filled with inert gas and rewelded etc. RT Racing did the work for me.

[jchase]

I used an epoxy based metal repair from B&Q to seal the many corrosion holes on my 280 2+2 aluminium fuel tank.
(Yes, the 2+2 has a single in board tank - eek ) Curiously the corrosion was either side of every weld, so I guess the welds will eventually fall out.

You have to have the metal shiney and apply the stuff right away, as it doesn't seem to take if you have an oxide layer - even ten minutes is too long! . I can't comment on steel tanks.

-Jim

[racingsnake]

I used the epoxy stuff on an Opel Manta tank a few years back - worked a treat, i would have a go with it if i were you before a big strip down - nowt to lose. (except the car in a big ball of flame LOL)

[adam quantrill]

What if you fill the tank completely with water and weld it - surely no gases then to go bang? Just an idea.

[Number 7]

Thanks guys. I think I'll give the filler a go, especially as that outlet is not completely submerged all the time, and it is a tiny leak. I assume the real purpose of that pipe is to allow air to pass between the two tanks, and prevent vacumn locks. The fuel itself obviously runs between the two thro' the lower pipe.
If as you say Steve H it does leak, then I guess I'll have to remove the tank.

7.

[jchase]

Oh, Just read the initial messages again.

I did try the metal loaded two part epoxy first of all, the silvery stuff, which is supposed to be especially to repair aluminium - It didn't work for me, but it wasn't the Hermatite stuff, some other brand.

The cheapo B&Q stuff is a two part epoxy that sets green ( says it is fuel stable) - it worked for about three months, till I sold the car, and it had smelled strongly of fuel inside the car proir to that. If you have to fix a fracture, it may not be strong enough unless you put lots on in several layers. My expereince was with lots of tiny pin-holes either side of the welds in the single piece alloy tank, so more of a filler than anything structural.

-Jim