I spent today scuffing horizontal stab parts in preparation for priming. While building the vertical stab I used a product called PreKote to prepare the aluminum parts for priming. It is a relatively simple process, but care must be taken to not allow the solution to dry on the part. On the horizontal I began by using PreKote on the spars and doublers, but quickly realized I wasn't up to the task of doing all of the remaining parts this way. The horizontal stabilizer has a much higher parts count so the prep time would increase dramatically. I spent the rest of the day scuffing the parts with maroon scotch-brite. Once the parts were scuffed I dimpled them as needed and will wipe them with acetone just before priming with AKZO.
The horizontal stabilizer has a couple of unique nose ribs and inspar ribs that attach to the spar at an angle. These are the most inboard ribs along the spar. I had bought a rattle can of NAPA 7220 self etching primer to try somewhere along the way. This 7220 primer would save me the setup and mixing of the epoxy primer if I had just a couple small parts that needed primed. I tried it out on these unique parts to see how it performed. These ribs will not be buried in the skin so I can see how it holds after assembly of the component is completed.