Rudder Anodes
A rudder anode is a sacrificial element (usually made of zinc or aluminum) essential for protecting the rudder blade and submerged metallic components from galvanic corrosion. It is bolted or welded directly to the structure to attract corrosion, preventing damage to the rudder's metal, and should be replaced every 1-3 years.
Function
It acts as cathodic protection, "sacrificing" itself by corroding before the rudder or other metallic steering components do.
Materials
- Zinc: Ideal for use in salt water.
- Aluminum: Suitable for both salt and brackish water.
- Magnesium: Exclusively for fresh water use.
Installation
It is fixed to the sides of the rudder blade or near it. It is crucial to ensure good direct electrical contact with the metal; therefore, there must be no paint in the contact area between the anode and the rudder.
Maintenance
- Do not paint: Painting them nullifies their sacrificial capability.
- Periodic Inspection: Ensure they maintain proper contact with the water.
- Replacement: They must be replaced when they have been consumed by 50% or more of their original volume.
