ANODE SHAFT 50mm

Function and technical context

This 50 mm shaft anode is part of the boat's cathodic protection system, acting as an electrochemical sacrifice to protect the metal propulsion shaft against galvanic corrosion produced by continued immersion in salt or brackish water. Being manufactured with a metal with greater electrochemical activity, the anode is preferably consumed, preserving the integrity of the shaft and avoiding accelerated degradation of the stainless steel or bronze that composes it. A corroded propulsion shaft can generate abnormal vibrations, loss of propulsion performance and even structural failure of the axle line, with the serious safety and cost consequences that this entails. The CMXC-50 reference is designed for 50 mm diameter shafts, guaranteeing a precise fit and an adequate contact surface for effective cathodic protection.

When to replace this part?

Shaft anodes should be inspected at least once per nautical season and replaced when they have lost approximately 50% of their mass, since below that level their protective capacity is seriously compromised. Symptoms of a depleted anode include visible pitting on the surface of the shaft, unusual roughness to the touch in areas close to the anode, or even reddish or greenish discoloration indicative of active oxidation. Annual preventative replacement, ideally during winter stranding or spring tune-up, is the recommended practice by marine maintenance professionals to avoid costly stern tube shaft or bearing repairs.