ANODE SHAFT 2''

Function and technical context

Shaft anodes are fundamental elements within the cathodic protection system of a vessel: their mission is to sacrifice themselves electrochemically to protect the tail shaft and other submerged metal components against galvanic corrosion. Made of high purity zinc alloy (reference CMX-9), this anode is installed directly on the 2-inch diameter propulsion shaft, forming an active barrier between the noble metal of the shaft and salt or brackish water. Without effective cathodic protection, the shaft suffers accelerated corrosion that compromises both the structural integrity and the sealing of the stuffing box, which can lead to vibrations, premature wear of the shaft line bearings and, in extreme cases, water entry into the hull.

When to replace this part?

A shaft anode must be inspected at least at the beginning and end of each navigation season, and replaced when it has lost approximately 50% of its mass, presents an irregular surface with deep craters, or its active surface has become covered with calcareous deposits that prevent direct contact with water. As a general guideline in salt waters, annual replacement is the practice recommended by most shipyards and nautical maintenance shops. Renewing the shaft anode preventively before it is completely used up is the most economical measure to avoid replacing the propulsion shaft or repairing the stuffing box, interventions that require the beaching of the boat and a significantly higher cost.

Compatibility table