Explanation of Bonding System


Can anyone provide an explanation of the bonding system on the Super Maramu? I have looked through the forum and tried to interpret various messages that mention it. But I can't seem to put it all together so it makes complete sense. How and where is it laid out? What should you be know when installing new equipment? How do you check it and what are the signs of trouble?

I want to be able to add/replace various 24V and 220V things (e.g. instruments, cabin fans, microwave, etc.) but not until I fully understand.

Thanks all.

Ian Townsend
Loca Lola II
Brunswick, GA

Duane Siegfri


When you're back in Brunswick let me know, we're on dock 14 in BLM.

First, I'm not an expert in bonding systems.  But here is what I understand.

If you connect different metals together with a conductor, one will corrode (the anode and less noble metal), and the other will not (cathode and more noble metal).  

Seawater will conduct electricity.  

When seawater is in contact with different metals (say a stainless steel pump impeller and a bronze seacock) one of these is less noble and will corrode (the anode).  Zinc is more anodic than the other metals on your boat.  By connecting all the metals that are in contact with seawater, and then connecting that wire to the zinc anode on the rudder, the zinc will corrode and protect the other metals in contact with seawater.

This is a form of "cathodic protection", check wikipedia for a more detailed explanation of cathodic protection.  This is an electro-chemical reaction.

Wanderer, SM #477