Finally time to glue the rear wing spar in place. You would think once was enough, but I had to learn all over again that when gluing a tapered joint, it may clamp nicely dry, but when wet with glue, it is prone to slide all over the place. Thus my first attempt on the right side ending in an aborted takeoff. I had to pull the spar and wipe the glue off, and since this stuff starts to set right away, it was a bit of a struggle. The worst part was the joint on the fuselage frame. It was the first to be mated, and it is a big joint. It was almost too strong to separate without breaking something, after only 10 minutes of curing. But, I got it all cleaned up, and sanded everything down once again. Next time, I used 1/8" wood alignment pins on all the joints. I also stapled plywood to the ribs to stabilize them, making it easier to push in the pins. Again on the right side, one pin broke off when I was inserting it. I found out the pins go in better when they are sharpened on one end. Here is a view of the left wing showing the ply reinforcing, and the glued in rear spar.
Now that the rear spar is in place, the trailing edge ribs can be installed. Most of these are in the ailerons and flaps, so there are only three on each side that are actually glued to the spar, two on the inboard end, and one outboard. The ailerons and flaps are still all one piece, including the trailing edge strip. I've attached the aileron/spar assembly to the wing spar with the hinges in order to get the trailing edge strip in place for gluing these ribs in place. This picture shows the outboard trailing edge rib clamped in place. It's great to see some skin in the wing area!