Rudder Dimpling Questions

I just finished the drilling of my rudder and I am now in the dimple/deburr phase (yuk!) but I have a few questions...

How the heck do you dimple the aft few holes in the rudder tip rib (R-903)? I have vise-grips dimpler and pop-rivet dimpler, and neither will fit in the narrow space. I have read suggestions elsewhere to use the pop-rivet dimples, but the problem is I can't get the mandrel in between the rib flanges. Any suggestions?

The other thing I am not clear on is whether or not to dimple the upper most row of holes, used to attach the fiberglass tip, in the skin and counterbalance skin (R-913). I have looked at a few web sites, and as far as I can tell, it looks like most people aren't dimpling these holes yet. The directions say to dimple and #30 drill the aft three holes, so I assume I should just leave the others alone for now. Am I on track here?

Thanks!

rudder dimpling

To dimple the last few holes in R903, you can bend the flanges out a bit to get your vise-grip dimpler in place.

Don't dimple the holes for the tip attachment until later.. this makes it easier to fit the fiberglass tip.

Vern Little
RV-9A

Thanks Vern!