ANODE SHAFT 40 mm.

Function and technical context

The shaft anode is a cathodic protection element that is installed directly on the tail shaft of the boat, acting as a sacrificial metal to protect the stainless steel or bronze of the shaft against galvanic corrosion produced by the action of salt or brackish water. Being made of high-purity zinc or alloy, the anode preferentially corrodes, preserving the integrity of the shaft and associated mechanical components such as the hub, propeller and shaft line bearings. Without adequate cathodic protection, the shaft can suffer pitting, loss of section and breaks that seriously compromise navigation. This CMC-40 model is designed for 40mm diameter shafts, ensuring a precise fit and effective electrical contact.

When to replace this part?

The clearest symptom that the shaft anode is exhausted is the visible reduction in its mass: when it has lost between 50 and 70% of its volume, it must be replaced immediately, since its protection capacity is compromised. Inspection and replacement is recommended at least once per nautical season, coinciding with the annual beaching and inspection of the hull, although in areas of high electrical conductivity of the water or with parasitic currents consumption may be higher and require intermediate inspections. Replacing the CMC-40 anode preventively each season is the most economical measure to avoid severe damage to the propulsion shaft, the repair or replacement of which involves a much higher cost.