Heat Exchanger Zincs

We can’t expect everyone who buys a boat which is new to them to know absolutely everything about that boat and often the previous owner is not around to show you all that needs done in order to keep up on maintenance.  One easy maintenance item are the “pencil zincs” inside of 99% of heat exchangers.  The heat exchanger transfers waste engine heat from the coolant loop to the raw (or sea) water.  Because it is metal and in contact with salt water we need to take special measures to protect the heat exchanger from corrosion.  This is accomplished mostly through small zinc anodes which are inserted into a threaded port on the exchanger.  It surprises me how often boat owners have no idea that there is something about the exchanger which needs any service much less regular service.

Below is a photo taken from the online Sailboat Owners Forum:

Heat exchanger

When pencil zincs are left too long there are a number of things that happen.  Most importantly they will loose their protective capacity over time and they will break off and tend to clog the exchanger channels.  This condition will slowly allow damage or corrosion on the heat exchanger itself and will result in having to limp home and a costly repair bill.

I recommend everyone research the different maintenance items required to keep your investment in good working order and if you don’t have any idea of where to start then give me a call and we can set up a time to have a knowledgable person come onboard to make a maintenance checklist.  At Tasman Boat Company, with a survey report we generally include a link to appropriate engine manuals if one is not found onboard and provide any consulting needed to help the new owner understand how to keep things running.  This extra step helps the proud owner get through that first year without any user error caused damage and we always like to hear stories of successful boat ownership.

Happy Boating!