Beginning Horizontal Stabilizer, Days 1-3
With my shop all setup, most of the needed tools acquired and parts ready to go, it was time to start building!
Day 1 (5/23/20): Horizontal Stabilizer, Rear Spar Assembly
The first parts I needed were the two HS-609PP reinforcement bars and two HS-603PP spar channels. After breaking their edges, I laid the HS-609PP’s into the spar channels, roughly aligning the pre-drilled holes to visually gauge if the bottom surfaces of the -609’s laid flat on the -603’s. The flange radius on the spar channels tend to prevent the -609’s from laying flat, as they did in my case. I used a Vixen file to carefully remove material from the pertinent edges of the -609’s until they fit flat.
Day 2 (5/24/20):
I finished fitting the -609’s to sit flat. Next, I rounded the noses of the -609’s per instructions, creating about a 1/4″ radius on each corner. To do this, I used my new 6″ 7A Scotch-Brite wheel.
Creating the rounded corners. The one side could use a little more rounding. 
6″ 7A Scotch-Brite wheel with my custom 3d printed 1″ to 5/8″ adapter
All surfaces of the -609’s need to be smoothed to a 400 grit-like finish, removing all milling marks and scratches. For the most part I did this by hand with 220 and 400 grit sandpaper, and maroon Scotch-Brite pad. I did use a 1″ Scotch-Brite wheel on a die-grinder for the more stubborn marks. Overall the finish came out pretty nice! On Day 2 I finished one -609.
Day 3 (5/25/20):
Finished smoothing second -609. Clecoed -609’s into -603’s. I reamed the attachment holes to #30. Next, I marked the 8th holes from the ends to be drilled to size #21.
The two HS-412PP’s and two HS-413PP’s were found, which I positioned the left side parts and match-drilled using #30 reamer. I had to stop here as I ran out of 1/8″ Clecos. I know, such a rookie mistake! Backup is on the way.
