Metal Guide

Al
Suitable for salt & fresh water
Mg
Suitable for fresh water
Zn
Suitable for salt water

Follow our colour coding for easy identification of metals.

Rudder AnodesRudder Anodes

Rudder Boat Anodes

Rudder anodes, also known as sacrificial anodes or zinc anodes, play a crucial role in protecting the rudders of boats and ships from corrosion. These small, metallic components are typically made of zinc, magnesium or aluminium alloys and are strategically attached to the rudder or other submerged metal parts of a vessel. The primary purpose of rudder anodes is to sacrifice themselves to corrosion, effectively diverting the destructive forces away from the rudder and other vital components.

Rudder anodes operate on the principle of galvanic corrosion protection, which is a form of electrochemical protection. When two different metals are in contact with each other in the presence of an electrolyte like seawater, a natural electric current flows between them. In this process, the less noble metal (the anode) corrodes sacrificially, preventing the more noble metal (the rudder) from deteriorating. 

Regular maintenance and replacement of rudder anodes are essential for ensuring the continued protection of the rudder and associated underwater components. Over time, the anodes erode, becoming thinner as they fulfill their sacrificial role. When a rudder anode has corroded by around 50%, it should be replaced promptly to maintain the integrity and longevity of the rudder. Monitoring the condition of rudder anodes is a standard practice for boat owners, and it is an integral part of routine vessel maintenance to prevent costly and potentially dangerous corrosion-related damage to the rudder and hull.

As mentioned, rudder anodes are made from three metals – aluminium, magnesium and zinc.

Aluminium rudder anodes offer protection in salt and fresh water, whilst zinc rudder anodes are more suited to salt water as the impact strength of the metal is superior compared to aluminium and magnesium. Magnesium rudder anodes are only suitable for use in fresh water, as the alloy reacts far more rapidly when exposed to sea water.

Why choose Anode Outlet?

Since 2009, we've been helping boat owners worldwide protect their vessels with our leading range of anodes for rudders, plus boat hulls, propellers, shafts and much, much more.

We pride ourselves on our customer service, and aim to make it as easy as possible for you to find the right anodes for your requirements; so if you have a mystery anode, contact us, and we will help you identify it! All our orders are shipped out on a fully tracked, next working day service - although if your order is urgent, please call us on 01634 568011 to confirm stock availability.