22/08/2008 - Finished drilling and countersinking and dimpling left aileron

Time to attach the leading edge to the trailing edge.  Note the bottom of the aileron where the one skin meets the other, the holes are opened up to #30 to accept CS4-4 blind rivets.

The same occurs for the holes that will have the same blind rivets hold the counterbalance pipe in place.  When I was drilling these holes I started to wonder how they would be dimpled without crushing the skin, but a little research showed that once the pipe is countersunk (2nd picture) then by clecoing the pipe back to the skin and holding it firmly with wood underneath to support it (3rd picture) and using the male die in a drift of some kind (i just used wood as before and can be see in the 3rd picture) a quick smack with the hammer formed the dimple in the exact shape as the countersink in the pipe underneath.  The last picture shows the blind rivet sat in the newly formed dimple.