Replacing the Zincs or Anodes on Meandering Joy

Bear in mind as you read this that I do not understand everything about how the boat works. When we first bought the boat I was so overwhelmed with new information that I took the most basic lessons and moved on to the next topic. Now that we have been on the boat for 5 years, I have taken a little bit more time to explore different aspects.  

Over the years, I have heard Steve telling a diver to replace the zincs, or check on the zincs while cleaning the bottom of the boat.  It was my basic understanding that the zincs.  I learned this morning while preparing to write this post that the zincs are more formally called anodes.  The reason he calls the anode a zinc is because most marine anodes are made of zinc.  An anode is the main component of a galvanic cathodic protection system which is used to protect buried or submerged metal structures from corrosion.  

In order to thwart underwater corrosion of these metal structures a third metal is added into the circuit, preferably one which is quicker to give up its electrons.  This piece of metal or zinc, in our case,  is called a sacrificial anode.  

On boats, zinc is used because it has a higher voltage in the water so the current will be more inclined to flow from it than from the propeller or bow & stern thruster To complete the electrical circuit, the zincs must be connected to the items they are intended to protect.

To increase the effectiveness of the zinc, it needs to be attached as close as possible to the metal it is supposed to be protecting.  It also needs to have clean metal to metal contact.  This is provided by either connecting the zinc to the metal directly or by a wire.  

The basic rule of thumb is to replace the zincs when they have been depleted by fifty percent.  Water pollution, water flow & current, pollution, temperature and salinity all affect the life of zincs.  

So why are you getting a lesson on zincs today.  Well, mainly because I needed the lesson but also because I have some great pictures of Steve replacing the zincs himself.  The water is so clear here that we don’t need a diver to get under the boat for this chore.  

Steve uses an underwater breathing system designed by Snuba International (Snorkel/Scuba forms Snuba).  Instead of getting air from a tank like a diver, the air is supplied by a long hose connected to compressed air cylinders.  He also wears fins, a mask, wetsuit and weights while underwater.  

Thanks for enduring  my lesson in zincs.  I think we stay young if we try to learn something new every day.  

Joy