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 is one of the BoatUS Magazine's panel of experts. 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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