Big day for riveting the left skin. My neighbor Darren came over to help. Planned on back-riveting everything, but the double offset back-rivet set wouldn't sit well on the rivet tails. The set just wasn't centered enough on the rivet. I even sanded a flat spot in the plastic tip, but still was cleating over the tails. Plan B - rivet everything with the flush set. Darren worked the gun, and I had the bucking bar. Most of it was pretty straightforward. There we a couple tough spots on the rear spar at the aileron bracket and at the inboard doubler. I don't see how these are buckable. Going to order some pull rivets for those. Next -10 I build; I think I'll wait to rivet the aileron bracket and the inboard doubler until after skin it on. [5/25 update - got these rivets bucked with the foot end of the bucking bar.] Got all the ribs and rear spar in about a 3.5 hr session. Later in the evening, installed and taped the front spar rivets on the left skin. I did note a couple things I wish I had anticipated. At the skin overlap, and also at the J channel overlap, there will be small gaps between the supporting structure and the skin. If you just buck these rivets normally, it will put a slight bend in the skin. This is the only "defect" in the skin that we had - otherwise flawless. Might try to buck a little more softly on the right skin, I don't know. It won't be noticeable when painted. 5/23 - Darren came over this evening and we knocked out the remaining rivets in about 40 minutes. Then I proceeded to squeeze the rivets at the wing root along with the nut plates. Made the small doubler for the area that I had to redrill - looks pretty solid. Struggled with the inboard doubler at the flap attach bracket, right where the skins overlap. The rivets called for were a little short, so I drilled them out and installed longer ones. The combination of enlarged hole and longer rivets made them all cleat over. I will order some cherrymax rivets for those holes. Purchases: ACS: 3/32 countersunk cherry pull rivets 8/27: I had installed the cherry rivets at the inboard doubler but wasn't happy with it. Not all cherry rivets are cherrymax, and the options for -3 are limited. The ones I got didn't seem very structural. I opted to drill them out and use -4 oops rivets instead. They look more solid, and the thicker shank allowed me to use a good length without them cleating over.