It was a beautiful November day with sunny skies, temperatures in the upper 60s / lower 70s, and no wind – perfect for taking parts outside for priming! I adopted my priming process from a fellow builder down the street. I started by scrubbing each part with Bon Ami and a gray scotch brite pad. This both scuffs the piece for better primer adhesion, and cleans contaminants from the part. I wore rubber gloves through this process to keep oils from my skin off the parts during the cleaning process. Following the scrubbing, I rinsed the parts with clear water and dried them with a microfiber cloth. If the water sheets off the part evenly with no droplets / water spots, it is done. I then let the parts air dry in the sun prior to priming.
Since this was a fairly small priming job (7 parts), I went with a Dupli-Color rattle-can self-etching primer from the auto-parts store. The primer is intended for bare metal including aluminum, and it received good reviews on-line including an aircraft builder. I plan to go with something like P60G2 for larger jobs later in the build.
I was happy with the results – especially for my first time doing anything like this. The parts were essentially dry to the touch within 10 – 15 minutes, so I could flip them and prime the other side. I let the parts cure overnight in the garage before working with them.