ALUMINUM STERN ANODE 146x64

Function and technical context

The stern anodes are cathodic protection elements located in the stern area of the boat, specifically in the tail of the outboard motor or in the inboard transmission, acting as an electrochemical sacrifice to protect the noble metal parts of the propulsion group against galvanic corrosion. This aluminum anode with dimensions 146x64 mm is designed to be installed at the stern of the engine, interposing its metallic mass between the water and the critical components of the transmission, propeller and shaft. As aluminum is a material with greater anodic potential than stainless steel or bronze, it corrodes in a preferential and controlled manner, thus preserving the parts of greatest mechanical value. Its correct installation guarantees that electrolytic corrosion is concentrated on the anode and not on casings, shafts or couplings at the stern of the motor.

When to replace this part?

The main symptom that a stern anode needs replacement is the visible reduction in its mass: when the anode has lost approximately 50% of its initial volume, it must be replaced immediately, as it loses protective effectiveness and can leave adjacent metal parts exposed to galvanic corrosion. In salt or brackish water areas, it is recommended to check the anodes at least once a season, ideally during winter stranding and spring launching, while in fresh water the consumption rate is lower although it should still be inspected. Replacing the anode preventively before each nautical season is the most cost-effective measure to avoid serious damage to shafts, propellers and aluminum housings, the repair of which involves a much higher cost than the anode itself.