Repairing cracks in rudder skin

[DVTAV8TOR]

Does anyone have any solutions (other than stop drilling) for repairing a small crack in the rudder skin . . . or at least a way to stop them from running?

[Steve Barnes]

I don't see any way around stop drilling. However I would take it a step further and experiment with injecting silicone in to the stop drill hole with a hypodermic needle. When I built my empanage I filled the trailing edges with silicone and 800 hours later never had a problem. Another way to possibly silicone the trailing edge is to pump it into a plastic tube through an existing or newly drilled access hole. What I believe causes most of the cracks is preload on the last rivet in the rudder stiffners combined with vibration. I haven't tried these after the fact silicone ideas myself. On my previous plane (an RV 4) I did have cracks and stop drilled the cracks and none of them grew past the stop drill in the next several hundred hours. Good Luck!

Steve Barnes "The Builders Coach"

[Neal@F14]

I know of an RV-4 owner that patched some cracks in his rudder skin by making some small discs of 0.016 aluminum sheet, and gluing them on over the stop-drilled cracks with proseal (sanded paint off down to the bare aluminum first over the crack areas) and then repainted the areas that were patched. It's been several years and several hundred flight hours later, and the cracks have not emerged from behind the disc patches, so apparently it worked.

[Kyle Boatright]

Originally Posted by Neal@F14

I know of an RV-4 owner that patched some cracks in his rudder skin by making some small discs of 0.016 aluminum sheet, and gluing them on over the stop-drilled cracks with proseal (sanded paint off down to the bare aluminum first over the crack areas) and then repainted the areas that were patched. It's been several years and several hundred flight hours later, and the cracks have not emerged from behind the disc patches, so apparently it worked.

This is similar to the click-bond fasteners and patches available through Spruce and other venues. I'm aware of several people who used them successfully to combat rudder cracks.

[woodmanrog]

stop drill, fill holes with pro seal or rtv and touch up paint. I had several cracks like this on the rudder and did this repair and 200 hours later no further cracking. I do have a new rudder kit in the hanger but it's been way to hot to build it so------. We'll probably attack the project in December. I also know of one RV6 that has had this problem for over ten years and 4000 hours of flying and there has been no further cracking since the early occurances.