ANODE SHAFT 1-1/8''

Function and technical context

This shaft anode is part of the boat's cathodic protection system, acting as a sacrificial metal to preserve the propulsion shaft from galvanic corrosion caused by prolonged immersion in salt or brackish water. It is installed directly on the propeller shaft, interposing itself between the metal of the shaft and the electrolytic medium of water, attracting to itself the electrochemical degradation that would otherwise attack higher-cost metal components. Without adequate cathodic protection, the shaft can suffer pitting, section thinning and loss of structural integrity, compromising the transmission of torque to the propeller and putting navigation safety at risk. The nominal diameter of 1-1/8'' (approximately 28.6 mm) determines the correct fit on the shaft, so it is essential to verify this measurement before replacement.

When to replace this part?

Shaft anodes should be inspected at least once a season – ideally at each grounding – and replaced when they have lost around 50% of their mass, present visible cracks or have worn out irregularly, since in that state they no longer offer effective protection. A clear symptom that the anode has failed or did not exist is the appearance of pitting or surface erosion on the shaft itself, which can lead to abnormal vibrations during navigation and premature wear of bearings and horns. Preventive replacement at the beginning of each season is the practice recommended by specialized naval workshops: the cost of the anode is minimal compared to that of a corroded shaft or repairing damage to the transmission line.

Compatibility