ANODO POPA DISCO Ø 200 (AL)

Function and technical context

The stern anode in an aluminum disc with a diameter of 200 mm acts as active cathodic protection of the boat, sacrificing itself electrochemically to prevent galvanic corrosion in the submerged metal parts of the hull and stern: tail shafts, propellers, rudder arms, supports and stainless steel or bronze structures. It works within the passive anti-corrosion protection system, being the last shield between salt or brackish water and the most critical and expensive metal components of the transmission and propulsion. Its large diameter disc geometry – 200 mm – guarantees a large sacrificial surface, especially suitable for transom or transom installations where exposure to water flow is continuous. If this component is completely consumed without being replaced, galvanic corrosion will directly attack the noble parts of the boat, potentially causing severe and irreversible damage to shafts, propellers or naval aluminum structures.

When to replace this part?

The clearest symptom that the anode needs to be replaced is a visible loss of mass greater than 50% of its initial volume: when the disc appears significantly thinned, fragmented or with deep pits, it has ceased to offer effective protection. Aluminum anodes for use in salt or brackish water must be inspected at least once per nautical season—before launching and at the end of the season—and replaced whenever wear exceeds half of their thickness, regardless of the number of hours of navigation. The professional recommendation is to change the stern anode preventively at each annual grounding: the cost of the anode is minimal compared to repairing or replacing a tail shaft or propeller damaged by galvanic corrosion.