ANODO DISCO POPA 140X35mm (ZN)

Function and technical context

This 140x35 mm zinc (ZN) stern disc anode acts as cathodic protection in the stern area of the boat, sacrificing itself electrochemically to protect the noble metal parts of the hull, tail shaft, propeller and other submerged components against galvanic corrosion. It works within the boat's passive anticorrosive protection system, interposing itself between the structural metal and the electrolytic medium of salt or brackish water. Its correct installation in the stern area is critical, since without efficient cathodic protection, seawater rapidly attacks the stainless steel, aluminum alloy and bronze of the propulsion and steering components, generating structural damage with high repair costs. Zinc is the most suitable material for navigation in salty and brackish waters, where its electrochemical potential guarantees active and lasting protection throughout the entire navigation season.

When to replace this part?

A zinc anode must be replaced when it has lost approximately 50% of its mass or when it has an irregular surface with deep pits, since in this state it no longer offers sufficient cathodic protection. The recommended inspection and replacement is annual, coinciding with the seasonal stranding, although in areas with high electrolyte activity or very conductive waters it may be necessary to inspect it every six months. Replacing the anode preventively each season is the most economical practice to avoid corrosion of shafts, propellers and hulls, whose damage requires repairs at a much higher cost.