An apparatus and method for method for joining materials includes a rivet (10) that may extend through a first sheet (26) to be resistance welded to a second sheet (24). The head (14) of the rivet (10) has a cavity (18) and vents (240) allowing adhesive (236) extruded from a pilot hole (28) to be received in the cavity (18) and vented in a direction parallel to the first sheet (26). The rivet (10) is deformed to an hourglass shape that fills the pilot hole (28) and displaces the first sheet (26) into the cavity (18). Rivet (10) dimensions allow for holding with a robotic gripper (1316) that can be withdrawn before welding. Methods of monitoring joint quality include comparing welding parameter profiles and images of good and discrepant joints.