I usually have some hair brained solution for a way to do almost anything that you are not supposed to do, but I finally painted myself into a corner of sorts, so I am asking for helpful suggestions here..... Here is the dilemma of the day- I have a Poly gas tank for a project[mine],it has to have a -in tank-[FI] fuel pump mounted. I have made an opening in the top for the pump,and have made a mount plate with three fittings[pressure fuel//-return fuel// wire loom]. My problem is this mount plate is[round 4" diam] 1/8" flat steel,and it will mount on a flat surface with 12 screws. unlike a factory made poly tank, mine is the textured surface where this mounts and not a milled flat surface as one would be manufactured for this purpose. WHAT SHOULD I USE AS A SEALER BETEEN THE TANK AND MOUNTPLATE? IS THERE ANYTHING CAPABLE OF STICKING TO THIS POLY SURFACE,THAT IS GAS PROOF?[TANK IS IN TRUNK] WAS THINKING A THIN RUBBER GASKET ALONG WITH A SEALER? ANY SUGGESTIONS???