Attaching the rear spar

A nice shot of the rear rib flange of the bottom rib that attaches to the rear spar. I was able to use my pneumatic squeezer to set these three round headed AN470 rivets. Another tip that I was reminded about after reading several posts on VAF was that you generally want to put the manufactured head of the rivet up against the part with the smaller thickness. In this case the metal for the rear spar and the rib are supposed to be the same I think. SO then the only rule would be to pace the manufactured head on the part where it is easier to access with the rivet set. I will go one further by adding my own little rule that I intend to stick with for the rest of the build. I will also apply the manufactured head of the rivet to the part that is more flexible than the other part, assuming it can be accessed with the rivet set adn bucking bar correctly. What I mean by that is explained in part by looking at the photo. The rib flange is the part that is able to bend and flex a bit. The rear spar web, on the other hand, is absolutely stiff, and will not budge very much, if at all.

Sometimes the flanges do not sit exactly flush the the part that they are being riveted to. In this case that is the rear spar. The only way to seat the rib flange so that it is nice and flush with the rear spar is to put the manufactured head of the rivet against the rear flange of the rib, so that the cup set on the squeezer can be placed over the head, and then enough pressure can be applied against the head to push the flange up tight against the rear spar web. This rivet clamping techique worked rather well, and helps prevent rivets from creating or "filling" the gap in between parts that may not be mated very well for one reason or another. Clecoes only hold parts together in these situations marginally well (not very well at all in my experience), which is why I have also ordered three 1/8 inch screw clamp clecoes, which should help cinch down the work pieces a bit better during riveting. Can't wait to try those out on the next rib-to-spar assembly!