Bondage

No, no, I’m not referring to activities in the book 50 Shades of Grey and nor do I mean forming meaningful relationships; I’m referring to the connecting together of your boat’s non-current carrying metal components to form a common ground for your DC electrical system.

Bonding, that’s the word.

The bits we’re talking about are the engine, gear box, fuel tanks, water tanks, the external casings of pumps and motors and so on. Typically, in a bonded boat these items would be connected together with copper conductors to a common bonding conductor which usually runs fore and aft down the boat. Not bonding your boat means leaving all those big chunks of metal isolated from each other.

The idea is that bonding everything together with appropriate copper conductors provides a large common ground for the electrical system, it provides lightning protection and it controls corrosion.

There are some who prefer not to bond. These isolationists aren’t necessarily anti-social; they just think that bonding leaves the boat vulnerable to stray-current corrosion outside the hull even though it is protected from stray current corrosion within the boat.

An important issue is the question of whether or not to connect your through hulls into this common grid. Personally, I prefer plastic (Marelon) through hulls and seacocks so, for me, it’s a moot point. But with metal through hulls you have to decide whether to connect them to the other components or to leave them isolated to look after themselves. The predominant view is that you should leave them isolated.

So, research the subject and make your choice – to bond or not to bond, that is the question. Bondage, that’s something else.