Sealing Fuel Tank Leak
 

The fuel tank is leaking on my RV12, not at the fittings so I assume I have a leak along one of the seams behind the tank, this only shows up when I leave the plane more than half full which I rarely do.

Can anyone recommend a short-term fix for this while I wait for a replacement tank? Would foil heating system tape work to seal a gas leak?

I'd stop by Auto Zone and see what sealing options they have.

Empty tank. Clean the external leak point with scotchbrite and acetone. Put proseal all over the leak area. Leak fixed...

Check the Front
 

Ted,
I had a similar experience, only leaked when full. Only spotted the leak when I pulled the passenger seat forward and stuck my head in front of the tank. Leak was hiding behind the "cross member" near the top of the front plate that mounts the fuel gauge sending unit. Couldn't see it when standing beside the plane or kneeling on the wing.

Since the leak was around a screw (not the plate perimeter) I just drained the tank, removed all the screws, cleaned up a bit. I dipped the screws in Proseal and reinstalled making sure that there was enough proseal "overage" to squeeze out from under each screw head. No more leaks.

Hope you're as fortunate and do not need to remove your tank.

Dave