ANODE SHAFT 1`` ALUMINUM

Function and technical context

The aluminum shaft anode for 1 inch shafts is a cathodic protection element designed to be mounted directly on the boat's propulsion shaft, acting as a sacrificial metal against galvanic corrosion. Its function is to attract the electrochemical oxidation process that occurs when dissimilar metals are immersed in water, concentrating corrosive wear on the anode itself and thus protecting vital components such as the shaft, propeller, horn and hull closures. It works within the submerged transmission and propulsion system, being especially relevant in through-axle installations in boats that navigate in both salt water and brackish water, environments where electrolytic aggressiveness is maximum. The aluminum alloy that makes it up makes it especially suitable for waters with medium-high salinity, offering a controlled dissolution rate that guarantees continuous protection throughout the nautical season. If this component is completely consumed or not replaced in time, the unprotected metals in the propulsion system are exposed to corrosion, which can cause irreversible damage to the shaft or propeller and lead to costly shipyard repairs.

When to replace this part?

The clearest sign that the shaft anode must be replaced is when it has lost more than 50% of its mass, its surface is completely eroded or it presents a whitish color and chalky appearance that indicates depletion of the active alloy. It is recommended to inspect and replace the shaft anodes at least once per nautical season, coinciding with the annual beaching or antifouling; In areas with especially aggressive water or on boats with leakage currents, the inspection must be carried out every six months. Replacing the anode preventively, before it is completely exhausted, is the most economical measure to avoid corrosion of the propulsion shaft and the high costs involved in its repair or replacement out of port.