What is an alkaline etch?

Etching aluminum in sodium hydroxide is by far the most common pretreatment for aluminum that is to be anodized. It imparts a matte finish to the end product. Alkaline etches are also used to strip off anodic coatings. However, under no circumstances should an etch-only finish be used in a finish product because there is no way to prevent the rapid onset of corrosion. An etch-only finish normally is regarded as an unsighly mess by our customers. It must be anodized immediately upon etching to preserve the uniformly satin appearance imparted by the etch.

View All Anodizing FAQs »