Aluminum boats are still subject to oxidation, and this can eventually weaken the hull and other components. Polishing it is a good way to maintain and extend the boat's life. Here are a few steps you can follow to keep it clean and corrosion free.
- Remove dirt and other gunk that may stick to the boat's body. Thorough cleaning comes first. There may be some surfaces where the dirt has stuck. In such cases, you may need to do some wet sanding. Make sure the sanding sponge is only slightly damp. You're going to have to cover tough areas three times. On the first pass, use something a little coarse, around 1000 grit. The second pass will need finer sanding grit, and the third will have the finest. While you're at it remember to work in circles, applying steady pressure, and to also frequently rinse and wring your sanding sponge. This is the most time-consuming step in the polishing job.
- Apply the metal polish. There are many general metal polish and cleaning substances commercially available. Pick one you've already used before, such as what you use on your car. Apply the metal polish, as instructed on the label, then buff it in a circular pattern until the polishing substance disappears and the surface is already shining. To quickly cover large areas, you can use a mechanized buffer. For smaller or more angular surfaces, use chamois cloth. If you're going to do everything by hand, it might save you from a lot of cramping to use a chamois glove, and this is also better for hard to reach areas.
- Start polishing the interior. Prioritize the boat's interior. If you often use the boat, polishing the boat's exterior would be quite pointless. In fact, most aluminum boat owners don't recommend polishing areas beyond the boat's trim. While polishing the boat's interior, exercise some judgment. Some exposed areas may need more work, while other areas will be fine with just one light coating. To make this procedure easier, you can use an alternative to a mechanized buffer. Attach a polishing ball to a hand drill, and use this for buffing instead. This could cut the time you'll spend polishing by half.
Unless you are entering the boat into an exhibit, regular cleaning and polishing will do to maintain the boat. The objective is preservation, not exhibition. A frequently used boat is always going to get stained and dirty, and there's no practical use to having it glaringly shiny on the water.