ANODE SHAFT 1-1/8

Function and technical context

This CMC-4 reference shaft anode is designed to be installed directly on the tail shaft of the vessel, acting as a sacrificial electrode in the cathodic protection system. Its function is to concentrate the galvanic corrosion process on itself, protecting the drive shaft, propeller and other submerged metal components against the electrochemical attack of salt or brackish water. Without effective cathodic protection, the shaft can suffer pitting and material loss that compromises the structural integrity of the transmission line. The CMC-4 reference corresponds to a shaft diameter of 1-1/8 inches (approximately 28.5 mm), which makes it specific for shafts of that caliber common in recreational and work boats.

When to replace this part?

Shaft anodes must be inspected at least once a season and replaced when they have lost around 50% of their mass, since below that volume their protective capacity decreases significantly. Signs that the anode is depleted include a badly eroded surface, fragmentation of the material or the appearance of visible pitting on the metal shaft itself, indicating that the protection has failed. It is recommended to preventively change the anode at each annual grounding to ensure continued shaft protection and avoid costly repairs due to advanced corrosion.