ANODE SHAFT 25 MM ALUMINUM

Function and technical context

Shaft anodes are cathodic protection elements that are mounted directly on the tail shaft of the boat, protecting it from galvanic corrosion caused by continuous immersion in salt or brackish water. This 25mm aluminum anode acts as a sacrificial metal: being more electrochemically active, it corrodes before the shaft, propellers, horn mounts and other submerged metal components. The choice of aluminum as a material makes it especially suitable for salt and brackish waters, offering effective protection without generating interference with on-board electronic equipment, unlike zinc anodes in certain conditions. Without healthy cathodic protection, the tailshaft can suffer pitting, material loss and accelerated corrosion that compromises the structural integrity of the driveline and can lead to costly shipyard repairs.

When to replace this part?

The clearest sign that the shaft anode needs to be replaced is when it has lost approximately 50% of its mass: it appears visibly reduced, irregular or with completely consumed areas. Shaft anodes should be inspected at each docking or seasonal maintenance, and as a general rule it is recommended that they be replaced annually or sooner if the boat frequently navigates in areas with high electrical conductivity or erratic currents. Replacing the anode preventively at the beginning of each season is the most economical and reliable practice to prevent the axis from being left unprotected, which can lead to irreversible damage and unplanned shutdowns.

Compatibility table