Wing Skins

 Look no clecos! A few of the rear spar rivets are still not in near the root; it seems these will be easier to squeeze once the wings are out of the build stands.

The easiest way I found to do this was from the trailing edge. Starting with the center rib of each skin, I would rivet the skin to the rear spar between the two center ribs. Then work up from the trailing edge on each rib. I could just reach the fourth rivet above the J stringer by laying on a creeper. 

After each skin was done on the lower portion, I would then corral a helper and rivet each rib the rest of the way up and then the main spar. I found a helper with a tungsten bucking bar was the easiest. I also used a wi fi endoscope camera hooked to my iPad so I could see around the other side and validate each rivet as we went. For $40 on amazon, the endoscope camera was well worth it. After a while, my friend would understand a good rivet and we would move along.

I took advantage of my rivet buddy not wanting to go home (because of traffic, not the wife, so he said) and was able to get all the top rivets on the right wing too. The rest I can get from the bottom with a creeper.

The wing is going slower than I anticipated, but I am taking my time and keeping the quality up.
After checking the twist, everything is as before. I did notice the right skin had to be cleco'd in a certain order to get all the holes to line up, so I ended up clecoing the skins on twice and using a cleco in every hole. There must have been some sag the first time. I am glad I didn't start riveting until both skins were on and fully cleco'd in place.

Small Steps are Still Progress

As the wing build continues, no real drama. The leading edges went on without much trouble; not nearly with the difficulty I envisioned from reading other blogs. As it turned out, most of the leading edge to spar rivets were reachable with the squeezer. I only had to drive about 10% of them, and of those only 5 on the right wing were blind and needed two people.

For the split strip between the tank and the outer leading edge skin, I tweaked the nut plates to better conform to the skin using a vise and some scrap brackets. This worked out well.

After installing the tanks, I noticed the skin thicknesses aren't all the same. Some are 25 mils , others are 32 mils. I wish I would have beveled the skins before assembly to make this transition smoother, but maybe there will be a chance to smooth the 7 mil step before paint.

I started riveting the skins on with my resident engineer-in-training. I am still trying to work out the best technique. I tried the long offset back rivet tool, but this takes so much umph on the gun the rivet heads aren't pretty; acceptable, but not pretty. So we tried the normal method as in the picture. This worked out well for the ribs, but still looking for a better method for the skin to spar rivets.