Flange
Single disc anode with steel insert
Sold as individual unit without hardware.
UK type disc anodes
Function and Use
The anode acts as an electrode that oxidizes preferentially ("sacrificing" itself) to protect the less reactive metal (like the steel of the hull) from corrosion. The central steel insert provides a secure mounting point and ensures good electrical contact with the structure being protected.
- Cathodic Protection: The sacrificial anode provides electrons, turning the protected structure into a cathode and preventing its deterioration.
- Marine Applications: It is fixed to the sides of the rudder blade or the hull (for steel hulls, they are usually welded or bolted on).
Common Materials
Materials by Environment
| Anode Material |
Environment of Use |
| Zinc |
Exclusively for salt water. |
| Aluminum |
Suitable for salt water and brackish water (lighter and more durable than zinc). |
| Magnesium |
Exclusively for fresh water use. |
Maintenance
These anodes must not be painted, as paint would nullify their sacrificial function. They should be inspected periodically (typically every 1-3 years) and replaced when they have been consumed to approximately 50% of their original size to ensure continuous protection.