ANODE SHAFT 90 mm.

Function and technical context

The shaft anode is the sacrificial element responsible for cathodic protection of the boat's tail shaft, a metallic component permanently submerged and exposed to galvanic corrosion generated by the potential difference between different metals in contact with water. When installed directly on the propeller shaft, the anode acts as a sacrificial metal: it preferentially corrodes and preserves the integrity of the shaft, propeller and other metallic elements of the propulsion system. This anode is manufactured for 90 mm diameter shafts (reference CMC-90), which determines a precise fit on the shaft without clearances that compromise its protective effectiveness. The absence or depletion of the anode on the shaft can lead to severe corrosion of the shaft itself, loss of material, vibrations, imbalance of the propeller and, in extreme cases, breakage of the shaft while sailing.

When to replace this part?

Shaft anodes should be inspected at least once a season, usually at the time of the vessel's annual beaching. The unequivocal sign that the anode must be replaced is when it has lost between 50% and 60% of its mass: from that point on, its cathodic protection capacity is insufficient to defend the shaft and propeller against electrolysis. In environments with high water conductivity (ports with strong electrical activity, salt water with high saline content or areas with intense galvanic currents) it is advisable to check the condition of the anode more frequently during the season. Replacing the shaft anode preventively at each stranding is the most economical practice to avoid damage to the drive shaft, the repair or replacement of which involves a much higher cost.