Aluminum flux and some solder.
Silver impregnated epoxy, and rough up the surface.
That's all I can think of off the top of my head.
Jim
I could try soldering..But I'll need lots of heat..
The point I have to ground is also an excellent heat sink.
Also...I think aluminum flux might be a specialty item.. A pita to
find.
One time I did mix epoxy with aluminum splinters..Worked good.
Commercial silver conductive adhesive sounds ok.. I'm clueless if this
can pass 15amps in the event of a ground fault. I'll check some
specs..
Also, I wonder if CSA would approve an earth ground wire bonded with
conductive adhesive to an aluminum box.
Maybe the ground wire will burn off...
Although, I'm not aiming for CSA..I do try to practice CSA
approvalable construction.
D from BC