Durinf this work session I completed all dimpling on the Horizontal stab and Vertical Stab spars usng the pneumatic squeezer. All the holes in the flanges were dimpled to size #40 to accept -3 sized rivets. I also dimpled the spar webbing of the Vertical Stab aft spar using the DRDT-2 dimpler. All holes were dimpled to accept #30 sized AN426 rivets as directed in the plans.. However I still need to countersink the reinforcement plate.