MAGNESIUM ANODE KIT

Function and technical context

Magnesium anodes act as a sacrificial metal in the cathodic protection system of marine thrusters, preferably oxidizing to preserve the metallic components of the transmission and tail against the electrolytic action of water. This kit is specifically designed for Volvo Penta DPS-A, DPS-B and SX-A tailpipes, covering all exposed areas of the propeller where electrolytic corrosion is most aggressive. Unlike zinc anodes (suitable for salt water) and aluminum anodes (mixed use), magnesium offers a more negative electrochemical potential, making it the ideal choice for freshwater and slightly brackish water environments. Without adequate cathodic protection, galvanic attack can irreversibly damage the shaft, propeller, transmission gears and propeller casing, generating high-cost breakdowns in structural components of the propulsion system.

When to replace this part?

Magnesium anodes must be inspected at the beginning and end of each nautical season, and replaced when they have lost approximately 50% of their mass, present visible cracks or have partially detached from their support, since at that point the cathodic protection is insufficient. On boats that stay on the water all season or sail frequently, it is common for wear to be complete in a single season, so annual replacement is considered standard preventative maintenance practice. Renewing the complete kit before each launch ensures that all the vulnerable points of the propeller are protected from the first day of navigation, avoiding costly transmission repairs caused by uncontrolled electrolytic corrosion.

Equivalent manufacturer part numbers