ANODE SHAFT 7/8''

Function and technical context

The shaft anode is a cathodic protection element designed to be mounted directly on the vessel's propulsion shaft, acting as a sacrificial metal against galvanic corrosion. It works in the underwater transmission system, where the tail shaft is permanently exposed to salt or brackish water, a highly aggressive environment for metals. Being a more electrochemically active metal than the stainless steel or bronze of the shaft and propeller, the anode preferentially corrodes, preserving the integrity of these components. Without adequate cathodic protection, galvanic corrosion can deteriorate the tail shaft, horns, supports and the propeller itself, generating vibrations, looseness and, in serious cases, shaft breakage while sailing. This 7/8'' shaft anode (reference CMX-2) is installed using clamps around the shaft, without the need for welding or structural modification.

When to replace this part?

Shaft anodes should be inspected at least once a season and replaced when they have lost approximately 50% of their mass, since below that threshold the cathodic protection capacity decreases significantly. Symptoms of a depleted or missing anode include visible pitting on the propeller shaft, rust on the propeller, accelerated corrosion on the shaft supports, and abnormal vibrations in the driveline. As a professional rule, it is recommended to replace the anodes preventively at the beginning of each navigation season, especially in areas with high water conductivity, to avoid irreversible damage to much higher cost components.

Compatibility table