I normally refuel from portable containers rated for gasoline that have no bonding capability. When I refuel from a bowser I will need a static earth point to ground the nozzle (CASA AC21-99 refers). Today I installed, with the help of PGC (thank you), an M5 rivnut through the top wing skin & rib flange adjacent to the refueling point. A bonding wire ring terminal was installed under the rivnut with the other end of the wire, also with a ring terminal, fastened under the head of one of the fuel tank mounting bolts. The resistance from the bolt to the tank opening was checked at 0.4 Ohms. Normally I'll have the rivnut plugged with a screw & when I require, I'll swap it out for the bolt.
