Adhesive method for solvent-based adhesives (rubber glue, G17, Diabond, etc.)
Apply a thin layer of adhesive so that it does not stick out from the bonding surface, and when the adhesive has dried a little, paste them together so that their rubbed surfaces meet.
If the adhesive does not adhere well, or if the silver surfaces are to be adhered together, use a dresser or similar tool to roughen the surfaces.