BoatHowTo · video

What this video covers

Corrosion of a prop shaft despite the presence of shaft anodes often stems from the use of 304-grade stainless steel rather than 316-grade, or from oxygen starvation within the rubber bearing or stuffing box.2:04 When a boat sits idle, the lack of water circulation prevents oxygen regeneration, leading to pitting corrosion that an external anode cannot prevent.2:15 Replacing the shaft with a more corrosion-resistant material like Monel or Aquamet provides a more effective long-term solution than adding external anodes connected to the engine.2:44 Regarding through-hulls, high-quality bronze fittings do not require bonding.1:07 However, many European-built boats use lower-quality metal through-hulls that necessitate a dedicated bonding system connected to an anode.1:01 Owners should verify the material quality of their through-hulls and consider replacing inferior fittings with composite materials like Marelon or True Design, or high-quality bronze.3:04 Regular use of the boat helps re-oxygenate submerged metal components, reducing the risk of localized pitting.2:31

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