Brief Description: Updrilling and Dimpling Right LE Skin / Ribs
Up-drilled the aft lower edge of the leading edge skin to the lower main spar cap extrusion.
Up-drilled the lower side of the right root doubler to #30.
Received my dimple die from Sonex yesterday. Had read on another builder's website that they had some adjustment to make in technique in order to get straight, centered dimples. I practiced on a scrap piece of .025" 6061, and am glad I did.
The nail that Sonex provides with the dimple die is a bit too bit for a #40 pilot hole. The 6 penny finishing nails I had would allow the head to pull thru the die, so I obtained some 6d box nails. These would only last awhile, based on the pressure I used to dimple the metal. Enough oomph and it would pop the head of the nail off. 6d work just fine on a #40 hole.
There are several ways to dimple/updrill the skins with respect to drill sizes used, etc. I started dimpling on the #40 initial pilot hole. The use of the die stretched the hole enough that a CCC-42 rivet would go thru the skin (firm push) without having to up-drill - the skin only. The ribs will have to be up-drilled just a bit.