Copper (and brass) are tricky though, as Fox mentioned.
My go-to glue people are Redwood Innovations - 023 9223 3310. Ask for Richard, tell him what you want to stick to what and he’ll come back to you (usually in a few hours) with the correct product and how to apply it.
Just butt the sheets together with a nice tight join, silicone under. That’s how they do commercial stainless over single sheet size.