What is used to keep corrosion from forming on structural aluminum alloy?

• A. An oxide coating or aluminum cladding.
• B. Pure water rinse.
• C. Zinc plating.
• D. Repeated sanding to remove any oxide.

Answer: (B)

Corrosion resistance for structural aluminum alloy comes from a protective surface barrier that slows or stops the chemical reactions with the environment. The most effective way to create that barrier is by forming an oxide coating, typically through anodizing, or by applying aluminum cladding that adds a durable, passive layer. This barrier shields the metal from moisture, salts, and other corrosive agents.

A pure water rinse, while useful for removing cleaners and residues, does not establish a lasting protective barrier by itself. It cleans but does not prevent oxidation long-term. Other options either don’t apply to aluminum’s corrosion protection (like zinc plating on aluminum) or actively remove protective oxide layers (re-sanding), which can worsen corrosion risk.