Spar tunnel dimples

[Darick]

I dimpled the tunnel skin and counter sunk (120* X .250) the wing attach angles as the plans show, then reassembled for a test fit. I was very disappointed to see how badly the dimples nested into the counter sink. I could easily insert a .015 feeler gauge between the two. It looks much worse if viewed from the side looking into the tunnel.

Now I realize the clecos don't pull as much as a rivet, but it doesn't look like the rivets will pull that much space. I'm thinking I'll have to tap the dimple back a little so it fits better into the counter sink.

Has anyone experienced the same thing and how did you deal with it?

[sonex892.]

Does the rivet sits flush in the dimple? If it does, I would countersink a bit deeper. Using a scrap piece of 1/8" aluminium to get the depth. When it sits flush to your dimpled part use that setting on your microstop to deepen the counterunk holes on the part.
Steve
Sonex 892

[Darick]

I understand. Thanks Steve.

[aferddaberts]

If the dimples don't nestle into the counter sinks of the female part deep enough to allow the two parts to lay flat against each other, I would counter sink just enough to allow them to.