The aft two rivets on the Top Skin/Ribs that were marked with orange tap during the last session, now had to be backriveted. To prepare for the backriveting, I have inserted the AN426AD3-3.5 rivets in the holes and taped them into place as shown below.
Then, I put the Flap on the 6’ backriveting plate I purchased a few week ago to complete the riveting.....similar to the excerpt in the plans. During the construction of the Left Flap, I took several photos of this process and included a short video of how I set the double flush rivets on the Trailing Edge (Part 16).
Moving along, the Flap was put back in the cradle to allow the Bottom Skin to be inserted between the Nose Skin and Spar (just like the Top Skin). Then the rivets common to the Spar were set. Just like with the Left Flap, you have to slightly pull back the Bottom Skin. This allowed access to get the bucking bar to the rear of the rivet for setting. The four pictures below show all the rivets set in the Nose Skin to Bottom Skin to Spar. Additionally, you can see the 22 MK-319-BS blind rivets set on Nose Skin to Ribs (and four to the Spar).
The two pictures below show the Inboard and Outboard ends of the Flap with the rivets installed and set. I have a little bit of a confession to make here. In the first picture, the three rivets circled on the Nose Rib are actually NAS1097AD4-3.5 “Oops rivets”. To install the MK-319-BS blind rivets, you first have to final-drill the holes to #33 (the 22 locations shown above). YOU DO NOT FINAL DRILL THE INBOARD AND OUTBOARD RIBS ENDS because you can squeeze them and install solid rivets. Well, I final-drilled them to #33.....oops! I decided a AN426AD3-3.5 designed for a #40 hole would not be sufficient for a #33 hole....as the rivet would expand in the hole and NOT set properly. So, I final-drilled the hole to #30 and installed the NAS1097AD4-3.5 rivets in these locations.....much better option.
During the next session, I will attach the Bottom Skin and Trailing Edge....and that should finish the Right Flap.