Plastic Fuel Tanks - Fitting Them

[Guest Ant]

I have a plastic fuel tank on my 2B as supplied by Chris Gibbons nearly 2 years ago. Whilst working under my car last night I noticed that one of the long panels of the tank is buckled. I've heard of this on someone else's car (can't find the post though - was it you?). The problem is how to attach the tank securely, but allow for expansion and contraction due to changing heat.

 

I had clamped it in place with an ally angle frame, using windscreen rubber to protect it, and lengths of threaded rod to hold it in place. My tank hasn't suffered any long term damage - when I undid the rods it bounced back to its original shape. I think the rubber strips probably saved it.

 

Anyhow, I now plan on chopping the threaded rods and putting a spring in them half way along, so the tanlk will be held firmly, but there is a means for expansion and contraction.

 

Have you fitted a plastic tank man fuel tank? If so, how have you allowed for this movement?

 

Ant

[Guest timswait]

My PTM tank buckled and started to leak along the bottom joint, presumably due to the stress on it. Chris fixed this for me free of charge and it's been refitted to the Hood for close to a year with no signs of leaks now. I think the main trick is to spread the load as evenly as possible. The first fitting had the tank up against a fairly narrow back so the back of the tank was being pushed in and was forcing the seam open. I've now fitted a nice wide piece of ply across between the tank and the back of the car to spread the force over the entire back of the tank. The tank is sitting on the two chassis tubes (protected by some foam rubber) and has two steel straps (protected by more foam) to hold it back against the ply. As I said it hasn't been in there that long, but touch wood it seems OK.

P.S I think the seams are the weakest part of the tank, so if these look nice and even you're probably OK, mine showed a fair bit of distortion by the time they started to leak.