I got it at the local parts store. It looks like red rubber cement, it is supposed to stay flexable though.

Very tacky stuff, not in a seafoam green kind of way.

I dont know about the copper spray, I looked at it, but I thought it was for head gaskets and intake to head joint.

I have also used spray paint, very heavy coats on the paper, assemble tacky. A ***** to get off though. :fork_off: