Each heat exchanger aboard has its own sacrificial zinc(s). These need to be replaced periodically, some more often than others. The three above are from the stabilizer hydraulic system heat exchangers. They have seen seven months of service.
There are two larger zincs on each diesel, and two smaller zincs on the transmission oil coolers.
Our habit is to change all zincs at the end of each season, or twice a year if the boat stays in salt water for the winter.
Posted by Steve Dashew (September 30, 2009)
September 30th, 2009 at 4:32 pm
Steve
I have been told not to use any Teflon tape or pipe dope on zincs as it seals the connection between the threads of the zinc and the casing?
Bo Leonard
September 30th, 2009 at 7:43 pm
It looks like you have quite a bit of Teflon tape on the threads. Have you ever considered that the zinc don’t work well unless the zinc is electrically grounded?
October 1st, 2009 at 12:17 am
Dave and Bo:
You are right in the need for an electrical connection. However, the zinc plug threads cut through the two wraps of tape and make a connection with the heat exchanger body.