Feb 17, 2020

How Much Sacrificial Zinc Does Your Boat Need?

Image 0563: "ZINC Photo for Blog"

How Much Sacrificial Zinc Does Your Boat Need?

Sacrificial anodes are utilized to protect boats from corrosion. Typically referred to as zincs, due to the lasting popularity of zinc anodes, sacrificial anodes can also be made of aluminum, magnesium, and various alloys. So, how do sacrificial anodes work to protect your vessel? What is the right amount of zinc to install onto your boat? Our yacht maintenance experts answer these questions to help you protect your boat from corrosion and “over zincing.”

How Do Sacrificial Anodes Work?

When metal surfaces like your boat’s hull go through extended contact with electrolytes, they undergo an electrochemical reaction known as corrosion. This process sees the metal return to its natural and weaker state as an ore. To slow down the process of corrosion, vessels need to implement methods of cathode protection. Cathode protection comes in multiple forms, including plating, galvanizing, and sacrificial anodes.

Sacrificial anodes work by corroding in place of your boat’s hull. Made up of highly active metals with more negative electrochemical potential than the metals they are used to protect, anodes attract electrolytes. The oxidation reactions are then transferred from the metal surface of your hull to the anode, which will be sacrificed to galvanic corrosion.

Sacrificial anodes need to be replaced regularly for continued effectiveness. The certified yacht technicians at our Fort Lauderdale boatyard and marina have plenty of experience replacing sacrificial anodes and proving other underwater dockside services, including boat bottom cleaning.

Can You “Over Zinc” a Boat?

Over zincing happens when there is too much anodic protection. Having an excessive number of sacrificial anodes installed on your boat can lead to unintended consequences. Boats with fiberglass hulls are less likely to be affected by over zincing, but wooden and metal hull boats are particularly susceptible to the negative effects of over zincing which include:

  • Burnback and discoloration
  • Paint delamination and flaking
  • Caustic wood rot

So, how much sacrificial zinc does your boat need? Cathode protection systems vary depending on the type and size of your boat and where it will operate. Typically, sacrificial anodes should have 1 to 2 percent of the surface area of the metal surface it needs to protect.

For the more precise measurements, have professional complete yacht care specialists develop the cathode protection and anti-corrosion systems of your boat or yacht. At Yacht Management South Florida, our certified technicians provide premium yacht management and yacht maintenance services.

Zinc replacement can be done dockside, but zinc installation typically requires a haul-out. Fortunately, we can schedule both dockside assistance and yard periods for your vessel. Contact us to talk with one of our customer service representatives today.

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