mastic in the channel around fuel tank

[PiperYelloGTV2k]

I removed around a kilogram of black mastic from the channel around the top of the fuel tank in the boot/trunk preferring not to live in ignorance of what lies beneath. Happily, all is well. Is the mastic original? I plan simply to waxoyl the channel as I like to see what is happening rustwise (hopefully nothing!).

[Alex]

No, it's not original. There should be a closed cell foam strip (approx. 15mm thick) sandwiched between the fuel tank outer lip and the aperture in the boot floor. You can buy this from e.g. Woolies Trim. You would cut this to the correct length, then glue it to the underside of the fuel tank lip with impact adhesive.

A bead of silicone sealant could also be applied around the boot floor aperture just to help keep the moisture out, before refitting the tank with its new foam strip, but that's all you need to do. You'll need to take the tank out to do this job properly - which then means you can also do other jobs like cleaning the inside of the tank itself and sealing it (go to Frosts for the POR-15 kit), attend to any corrosion in the rear panel, tighten the rear bumper bolts etc ....

Alex.

[rafael]

there should be a rubber seal between the fuel tank and the metal on which the tank is resting on. Usually that metal is very rusted. Perhaps you can check its state from below.