Initial Prep (Debur, Trim, Drill, and Cut)
10/14/2021 – 3.3 hours
10/15/2021 – 0.9 hours
The plans call for the entire vertical stabilizer assembly to be cleco'd together, and then to drill all the holes in the skin. This is a good opportunity to see how all the pieces fit together, and to ensure the preparation of the ribs and spars is adequate. The front is an especially tight fit. After clecoing the VS together, the front holes (left and right, top and bottom) are match-drilled from the skin to the top and bottom ribs. The rest of the holes (roughly 200+) are then final drilled from 3/32” to #40. I found the best method for me was to cleco every hole, and then remove the cleco and drill one at a time. It takes a little longer, but it ensures the best possible alignment between the skin and ribs/spars.
[Hole and Edge Deburring Tools, #40 Drill]
Final Prep (Dimple, Countersink, and Shape)
10/16/2021 – 2.3 hours
I used the 22” C-Frame and standard diameter dimple dies for most of the skin dimples. Access to the holes for the front spar are a little difficult to get to, but I found that a stip of duct tape over a rolled up towel on the exterior of the skin helped pull the skin out of the way for the opposite side dimples. I switched to the pneumatic squeezer for the holes along the top and bottom of the skin forward of the front spar, and went to the manual close quarter dimple die for the two forward holes on the top. The holes at the very top of the skin do not get dimpled at this time – they will be enlarged and dimpled when the fiberglass tip is installed. There are also six holes at the bottom that don't get dimpled (the rib beneath doesn't get dimpled either!) or riveted, but will be used later for the fiberglass tail fairing.
[22” C-Frame with #40 Standard Diameter Dimple Dies, Pneumatic Squeezer with #40 Reduced Diameter Dimple Die, Close Quarter Dimple Die, Blind Rivet Puller]
Prime
10/15/2021 – 3.3 hours
10/18/2021 – 1.5 hours
I started by scrubbing and scuffing all of the vertical stabilizer parts to prepare them for primer. I do this step before dimpling and countersinking because it is much easier to work with the smooth parts than tear up the Scotch Brite pads on the dimples. I'll go back to dimple and countersink before degreasing and priming the parts.
[Grey Scotch Brite Pads, Bon-Ami Cleanser, Dupli-Color Degreaser, Dupli-Color Self-Etching Automotive Primer (Green – Rattle Can)]
Assemble
10/21/2021 – 3.2 hours
10/25/2021 – 0.7 hours
The rear spar, doubler, and hinge brackets get riveted together to complete the rear spar preparation. I started with the AN426 rivets at by back-riveting the doubler, spar and lower hinge brackets. I clamped the parts to the back rivet plate as tightly as I could to get a nice flush finish on the forward side of the spar. Back riveting worked really well with the exception of the rivets closest to the 90 degree bend in the lower hinge brackets. There isn't enough room for the back rivet set in that area, so I switched to the pneumatic squeezer for those rivets. I also used the pneumatic squeezer for the remaining AN470 rivets in this section.
[Back Rivet Plate, Back Rivet Set, Pneumatic Squeezer, 1/8” Cupped Squeezer Set, Flat Squeezer Set]