Stupid strikes again

Today's session started off well; I clecoed the nutplates to E-615 in preparation for riveting.

 I had some help squeezing a couple of the rivets...

 And the finished product! I really enjoy using the rivet squeezer; it gives consistent, excellent quality results every time.

 As you see in the background of the above, Erin came out to help prep the elevator skins for backriveting. I jumped in and backriveted several lines, frustrated with my inability to get properly formed shop heads. I tried several different air pressures, different angles with the rivet gun, confirmed I was using the right length rivets, all with no improvement.

 And then it hit me: I had failed to put the stiffeners on and riveted the skin to...itself! $*!%&

 

I then made another mistake: proceeding with riveting on stiffeners, thinking I'd come back and drill out the stiffener-less rivets later.

Big mistake. I started carefully drilling out the malformed rivets, and somewhere around 1 in 3 or 1 in 4 were deforming the skin or damaging the dimple.

 

The first thing I did right was stop drilling, but now I'm stuck with the unpleasant alternatives of buying a new skin & stiffeners or attempting to drill out all the crap rivets and, with Van's concurrence, drilling the holes larger, deburring, dimpling, filling the enlarged holes with oversize rivets and adding additional rivets in-between for strength.

 

The latter solution appeals to the thrifty part of me, but drilling the holes larger will almost certainly result in edge-distance problems as at least 2 of the damaged holes thus far are larger than 1/8" rivets could fill. If the rivets aren't structural it may not matter and all of the damaged holes are on the bottom of the right elevator which means the error won't be visible. BUT - I'll know it's there.

 

I think I'm going to call Van's to consult their technicians tomorrow; however I think for $100, a little humble pie, and increased peace of mind the new skin is probably a small price to pay.

 

Lesson learned here is take it extra slow when I'm coaching other people, and talk through each step as I'm doing it.

 

Empennage: 2 hrs