Zincs

By Don Casey

Revised by BoatUS editors in April 2012

Anode and outboardThe longevity of a sacrificial anode is a function of its weight. The amount of protection it provides depends on its surface area. When a zinc lasts less than a year, you need one with more weight. If the protected metal shows signs of corrosion despite the zinc, you need more surface area.

Check all anodes at least annually; if half (or more) of an anode has been lost to corrosion, replace it. Don't forget to check the zinc pencil inside your engine's heat exchanger; you will find it (or not) under a brass plug in the exchanger.

 

Don Casey has been one of the most consulted experts on boat care and upgrades for 30 years, and a panelist on our "Ask The Experts" website for a decade. He and his wife cruise aboard their 30-footer part of the year in the eastern Caribbean. His books include Don Casey’s Complete Illustrated Sailboat Maintenance Manual, and the recently updated This Old Boat, the bible for do-it-yourself boaters.

 

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