Worked on left side horizontal stabilizer to final prep and prime. These parts had been scuffed prior to dimpling a couple of weeks ago and I found that fingerprints left on the parts showed as dark areas on the aluminum. I assume this was early oxidation and so made sure to scotchbrite all of these parts very well. Dark areas that were very stubborn were cleaned with 400 grit paper, followed by scotchbrite. Lesson learned to prime parts immediately after scuffing. Once all parts were cleaned, I washed with Dawn and warm water, again wearing gloves, and let them air dry. Used compressed air to blow any residual moisture out of the holes, set up the down draft table and primed all the skeleton pieces. Also primed inside the skin as I did with the right side. Parts are now ready for final assembly and riveting.
