Spars - Section 13

We are match drilling the "J" stringers to the existing spar holes. They actually don't attach to the spar but fit in the ribs as a stiffener and get riveted to the wing skins but share the same rivet spacing as the spar, hence the match drilling.

There are a lot of holes in those stringers. Rafa bought a deburring tool that you can run through the holes and a little tapered blade on a spring make quick work of the burrs with out taking off material or making the hole any larger.

Lots of plate nuts for holding on the fuel tanks and a lot of concentration to make sure to hold Vans tolerances. Making a mistake here could be really expensive.

Drilling for plate nuts, two spars at a time

The counter sinking is substantial to fit the .035 dimpled tank skins. Almost 3/8" is required to fit the dimple of the tank skin.

Tank plate nuts done, but there are other ones in the spar to come for the back of the tanks, inspection plates and a few other attachments.

Flap bracket parts match drilled to the rib and ready from priming. We scuff parts up with Scotch Brite attached to a Dremel Multi-Tools with a hook and loop pad. This works well and is better than doing it by hand. We are not removing the Al-clad, just dulling the finish enough for the primer to adhere.

A few holes on the punched parts from Vans that were not quite right. I think the punch may have bent. We made it work through progress match drilling and one rivet that was slight longer to do a little extra filling of the offensive hole.

Ready for AKZO!