Galvanising

Galvanising

Galvanising can prevent rusting. It is where a metal, such as iron, is coated by a thin layer of a more reactive metal such as zinc. This protects the iron underneath in two ways:

• Prevents oxygen and water from reaching the iron which prevents rusting as water and oxygen are needed for the rusting to occur.
• Acts a sacrificial barrier.

A sacrificial barrier is where the metal acting as a barrier is more reactive which means that it more readily loses its electrons instead of iron. Therefore, it will oxidise instead of the iron which prevents rusting. This has two main benefits:

• Air cannot reach the iron,
• Even if the iron is exposed (e.g. the sacrificial barrier is scratched) it is still protected because the barrier will protect it as it is more reactive.

Sacrificial barriers are higher in the reactivity series of metals than iron.