03 August 2013

Wings: Rivet removal in hard-to-reach place.

The rivets on the rear spar flange are difficult to buck over the doubler plates (both the flaps and the aileron doublers) because whatever bucking bar you use, it can be whapped into the AD4 rivets holding the plates in, damaging their heads (either shop or factory).  Sure enough, that happened on two rivets on the left wing when the top skins were going in.  These rivets necessitated removal.

With the top skins in place, removal of those rivets is very difficult because the drill bit needs to be long (and therefore harder to control) to clear the skin and the drill bit needs to be at a slight angle to prevent marring the skin.  I bought a drill extension because I didn't want a super long, thin, wobbly bit.  I couldn't afford enlarging this hole.  This could be used to start the hole on the rivet after smacking with an awl.

I also got a 6" #33 drill bit, intentionally small to avoid enlarging the hole.


Here is how the extension lined up on the rivet with a #40 bit.


A nicely centered hole of the right depth.  You can see the AD4 rivet on the right that's damaged too.


Head snapped off with the #33.


Hole after removal.


Rivet head and shank.  Perfect removal!

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