Rudder stiffener
 

My friend has an RV6, recently purchased. On the right lower side of the rudder, the skin has been vibrating or oilcanning causing a tear in the skin at the forwardmost rivet of the lower stiffener. What would be the best way to repair this? It appears that the area is pretty much contained and getting inside mean removing the skin. Something he would like to avoid.

Thanks in advance,

picture please?

This is a fairly common occurrence. I would suggest Stop-Drilling the ends of the crack, and keep an eye on it. I have similar cracks, and they haven't progressed at all since I stop-drilled them.