Anodizing is a process that creates a scratch-resistant and corrosion-resistant coating on aluminum alloy. During the process, the aluminum is submerged in a special bath and an electric current is passed through it. A layer of aluminum oxide, which can be tinted to produce different colors and which enhances the metallic look of the aluminum, builds on the surface. The oxide layer is much stronger than the aluminum itself, and also stronger and bonded more permanently to the metal than virtually any paint. The durability of the anodized finish is directly related to the thickness of the coating. Promenaid railings have an 18 micron anodized layer, the thickest commercial grade and equivalent to the finish of the highest quality aluminum doors and windows.
