Zincs & Alloys
The simple answer is to stop the corrosion of metals. The reason why they corrode is a little more complex but critical to know if you own a boat. In some situations, zincs may deteriorate at a rapid rate and by understanding how they work, you can troubleshoot your own boat.
First, to explain the chemistry, corrosion occurs anytime two or more dissimilar metals are placed together in a conductive solution (seawater). Corrosion is most severe on the least noble (most corrosive) metal.
Typically, boats have bronze, stainless steel, and various other metals. By placing zinc into the equation, we are adding a less noble metal that will corrode first but can be easily replaced. Using this more corrosive metal, we are protecting the more expensive components from corrosion.
As zincs deteriorate, they build up a coating that renders them less effective. This is why it is recommended to replace zincs when they are half deteriorated. How frequently is dependent on how much you run your boat, how many zincs you have, how your boat is wired, and how other boats in the marina are wired. It is always better to be safe than sorry. The cost of zincs and installation is cheap compared to the expense of your other hardware. If you are unsure of the condition of your zincs give us a call. It's probably cheaper than you think.
You can purchase sacrificial annodes (zincs) in a number of places:
If you have any questions about zincs & alloys, please