Shop thruster anodes at West Marine.

Galvanic corrosion is a type of corrosion that occurs when two dissimilar metals are in contact with each other in the presence of an electrolyte, such as saltwater. The more active metal (the anode) corrodes preferentially, while the less active metal (the cathode) is protected.

Galvanic corrosion can damage your boat.

Concerning boats, galvanic corrosion can cause significant (and expensive) damage to metal structures such as propellers, propeller shafts, bow and stern thrusters and other parts that are immersed in saltwater.

Sacrificial anodes protect underwater boat parts.

To prevent galvanic corrosion, boats require sacrificial anodes that are more active than the metal parts of the boat. These anodes are strategically placed on the boat and are designed to corrode preferentially, protecting the other metal parts of the boat.

Why do bow and stern thrusters need protection?

Bow and stern thrusters on boats use an electric motor to power a propeller that is located in a tunnel or a tube that is installed in the bow or at the stern of boats. The motor and the propeller are typically made of metal, such as aluminum or bronze, while the surrounding water is often saltwater. The dissimilar metals in contact with each other in the presence of saltwater create an anode-cathode pair which can result in galvanic corrosion.

Protect your bow thruster with sacrificial anodes.

To prevent galvanic corrosion, sacrificial anodes are installed on bow thrusters. These anodes are made of a more active metal, such as zinc (for saltwater), aluminum (for salt- or brackish water) or magnesium (for freshwater); and they are designed to corrode preferentially. As the anodes corrode, they will release electrons and provide a path for the flow of electrical current that would otherwise cause the less active metal parts of the bow thruster to corrode. By corroding preferentially, the sacrificial anodes protect the less active metal parts of the bow thrusters, including the motor and the propeller. It is important to periodically check and replace the sacrificial anodes as they will corrode over time.

Brands of Thruster Anodes Available at West Marine

Brands of thruster anodes available at West Marine include Side-Power, Lewmar, Sierra and Martyr.