Hats off to you Guy. You aren't being silly. I still need to test my plane with aa ohmmeter between the filler necks and the exhaust stacks (and ground too).

The other day at work I checked a Cessna 206 with a precision tester for bonding to test how the bonding a certified plane is. I checked it from a good airframe ground to the exhaust and the results were not good, it had infinite resistance. Next I checked it from a wheel axle bolt to ground and got .003 ohms (which just meets certified specs for bonding). FYI it is our standard practice (where I work) to hook the ground cable to the axle bolts when refueling.

What this tells me is that using an exhaust system isn't a good idea, even if there is proper bonding to the tank filler neck. I think there are several reasons. Stainless steel is not a good conductor and there are slip joints and gaskets the may be filled with exhaust residue.

Using the landing gear on a Kitfox with the Grove gear would not a good solution because of the plastic mounting blocks and paint. Even if there is bonding from the fuel tanks you would need to find a proper airframe ground to attach the fuel ground cable to.

FYI bonding is making the entire plane one potential. It is needed for several reasons: for static dissipation, to provide a path for lightening strikes and prevention of sparks when refueling. Bonding is done by connecting all of the components together with bonding straps. When you hook up a ground cable before refueling it makes the aircraft the same potential as the fuel pump system, which should be hooked to earth ground too.

In a Kitfox I really doubt there is any bonding obtained through the fiber glass tanks, nor through the fuel lines (I have rubber hoses from the wing tanks to the header tank). I think the only way to get proper bonding would be to connect the filler necks to the airframe or to connect directly to the filler neck as some are doing.