I used the pneumatic squeezer to rivet the top skin to the firewall. Unfortunately, I did not pay attention to the rivet length. I used the AN470-3-5 rivets along the entire right side of the top skin and firewall. Spacers were used along the rivet line and a second spacer was added along the right third of the rivet line. The rivet size should have been increased, but I was careless and did not check my work. All of the rivets were too short and smashed almost flush with the material. These will need to be replaced.
