FAQ: How does a sacrificial anode work

A sacrificial anode system is a form of protecting submerged structures from CORROSION by using sacrificial anodes, also known as galvanic anodes, which are the basis of traditional galvanic cathodic protection systems.

Sacrificial anodes are made of more active metals than the base metal structure that they are protecting. As a result, they oxidize at a faster rate than the metal structure to which they are attached.

The sacrificial anode method of cathodic protection is easy to install and requires little expertise. As they require no external power source, sacrificial anodes they are particularly suitable for smaller structures or those is simple and has been used for hundreds of years.

The sacrificial anode method of cathodic protection presents several problems owing to how sacrificial anodes work. Over the lifetime of every anode, large quantities of zinc, magnesium or aluminum are released into the water, together with heavy metals such as cadmium.

Moreover, a sacrificial anode system does not offer the same level precision as modern cathodic protections such as ICCP systems. There is, for instance, no means to check the efficacy of the protection offered by the sacrificial anode method over time without employing divers to conduct an underwater inspection.

Sacrificial anode protection methods also have a finite life. This means that they always need to be replaced, which adds to there already significant carbon footprint.