Sounds like a job for Friction stir welding..........Just
kidding........

If the panel will only be seen from one side, how about spot welding
tabs on the back side to hold the sheets together.

Dan

Ernie Leimkuhler wrote in message


My thoughtr was that the joint could be sanded with a DA sander to
leave almost no visible seam.
This would reduce the electrostatic difference so the seam should be
less visible.
The panels will be about 12 feet above a store front so I am more
worried about viewing distances of 20 - 30 feet.