RE: Questions regarding Flutter
Taping the hinge line will probably not solve the flutter problem. It is not the hinge line that is fluttering. It is very likely the outboard trailing edge tip of the aileron, elevator or rudder. The picture shows the cure for aileron flutter. A small piece of tape is stuck across the corner of the aileron (In this case). The control surface still has to move so the tape does not restrict the outboard tip completely. Try one control surface at a time until the culprit is found.
Flutter/vibration can be caused by many things unrelated to control surfaces.
Ed S