When the primer set, I began sanding for the final coat. I had already planned to secure the passenger vent fitting with riveted tabs (in case it came loose and fell into the control torque tube area), but I hadn't done this yet. Unfortunately, I flexed the panel too much while sanding and broke the JB Weld loose, so I die ground the old JB Weld away, riveted the fitting and applied new JB Weld.