Originally Posted by rockwoodrv9
Im having a hard time figuring out how the rudder got damaged along the trailing edge. I didnt think it was possible to contact the elevator at that point.
The entire mass of the rudder is moving rapidly to one side but then is instantaneously stopped by the rudder stop at one end.
The remaining mass of the rudder attempts to stay in motion which puts a twist load on the rudder. This is also how the indentations from the trailing edge of the elevators occur, even though there was likely clearance between the rudder and elevators at full travel.
The issue is amplified even more if it is a rudder with a counter balance weight.
It looks like this one might be a later rudder with the counter balance. If so, it would be an easy repair because it would essentially involve removing the skin and installing a new pre-punched RV-8 rudder skin.
If it is an early vintage (short) rudder, removing the skin and match drilling a new one would still be the simplest repair because the hinge points were established by the builder based on dimensions. It would be far easier to reuse the same sub-structure frame than making a new one that would properly fit the vertical stab.
I agree that the rudder should be replaced before further flight.
If it needs to be ferried, a light weight bent patch could be made and installed with blind rivets. It would be prudent to reduce speed slightly for the ferry flight.