These spars are at the leading edge of the wings and extend from the fuselage to about 1/3rd of the span. The spars have flanges at a 45 degree angle just to make life difficult. All of the rivet holes in the flanges (more than 80 per spar) need to be countersunk - not my favourite job, having previously destroyed the tail spars with my efforts. However this time the outcome is successful, though it took a couple of hours or so. See picture 1. I clecoed the spar flanges to a long piece of 4x2 which seemed to do the trick. See picture 1.
The inboard end of this stub spar has a doubler plate for additional strength. You can see the V-shaped part in picture 3. You can also see the back side of the clecoes holding it to the spar. The three end holes need to be countersunk on both sides (Pictures 2 and 3). A flush rivet will be squeezed here, and I assume the objective is to get the tail end of the rivet (shop head) to expand into the countersunk area.
