Raw Aluminum Oxidizes instantly. It takes special primers to get paint to adhere so Clear Coat isnāt a great idea. After sanding and polishing it it does take some time for ti to generate actual cristals of oxidization, like years, if itās not exposed to salts or other harsh environments. Oh, your skin oils may cause faster corrosion if your PH is acidic.
Once it is polished it will last for a long time. And already being polished makes it easy as cleaning it to get it back up to shiny with another quick polish. Car Wax will help on long term storage.
@ T18
I use Sodium Hydroxide crystals (Lye) dissolved in water and warmed in the microwave for a minute after dilution to help a weaker solution work better. Please read up on it as there are potential dangers involved. Wet sanding starts with 400 on a sanding block moving the block around the circumference. 800, 1200, 1500 and working up to 2000 Grit. Polishing with a Bounty paper towel with Mothers polish worked into the towel before using. Once the desired finish is achieved I use Dish detergent to wash off the Black polish from light and my hands. You will want to grease the threads after stripping anno off. Raw threads can be coarse and gall if tightened dry.
ALL sanding and polishing is by hand. Machines, buffers, dremels can not achieve a smooth mirror finish.