How does cast iron outdoor seating age compared to aluminum over decades?

Cast iron and aluminum are two popular materials for outdoor seating, but they age very differently over time. Cast iron is incredibly durable and can last for decades, but it is prone to rust if not properly maintained. Regular painting or sealing is required to prevent corrosion, especially in humid or coastal environments. Over time, cast iron may develop a weathered patina, which some find charming, but untreated pieces can weaken structurally.

Aluminum, on the other hand, is naturally rust-resistant and requires minimal maintenance. It doesn’t corrode like cast iron, though it can oxidize slightly, forming a dull surface layer that protects the metal underneath. Aluminum is also lighter and less likely to crack or chip, but it may bend under extreme stress. Over decades, aluminum retains its shape better than cast iron but lacks the same heavyweight, classic aesthetic.

Ultimately, cast iron offers timeless appeal with higher maintenance, while aluminum provides a low-maintenance, modern alternative that ages more gracefully in harsh conditions. Your choice depends on climate, desired look, and willingness to upkeep.