When exposed to the air, aluminum will naturally form a very thin oxide layer that builds up and keeps the material protected, but not for long. Anodizing is an electrolytic process that can ramp up this protection by making the oxide layer thicker and with an ordered structure. The new anodized layer is porous, which helps with sealing or coloring the metal with dye. It’s an affordable process, and you don’t need any special skills or equipment to do it.
Anodizing is particularly helpful for products that will get lots of outdoor use and be exposed to the elements. These include parts for bikes, cars, electrical enclosures, and outdoor furniture. The treatment also makes the material scratch-resistant, and it can act as an insulator since the coating is not conductive. That’s another reason it’s used for boats, architectural cladding, canoes, and even kitchen utensils. When aluminum is anodized, its sealed surface makes it easier to clean and maintain as it won’t react with elements that could otherwise stain it.
