Anodized aluminum is used a lot in the aircraft and aerospace industry. It can be done electrically and it can be done strictly using chemicals. The electrical process generally produces better results. Both give results dependent on how well the aluminum is prepared before the chemical or electrical "baths." You can achieve highly polished and "shiny" finishes if the aluminum is properly polished before the anodize process is begun. Even cast aluminum, not just aluminum sheets, can turn out bright finishes of any color, depending on the aluminum alloy the casting was composed of (e.g., 6061, 2024, 5052, 7075 series aluminum). Some firearms frames are anodized aluminum, ala Smith & Wesson, Ruger, and many more. With proper buffing to produce the micro finish desired, the most important step is a deep, long chemical etch just before the anodize process begins. It does make aluminum more corrosion resistant, though severe repeated contamination will eat through the anodize. I have seen aluminum framed handguns that were more than 50 years old that still looked bright and shiny. And I have seen aircraft parts that were 1 week old that looked like hell because they were improperly done to start with ~ ~ just my 2 cents ~ ~ jaknight
