OCC Forums

Zinc anodes

https://forum.oceancruisingclub.org/Topic1473.aspx

By Ariel - 6 Jul 2014

Has anyone any knowledge on electrolysis caused by " induction current "
I run a Domestic AC fan from shore power , all insulated cable, , ( free standing)
I notice zinc degrading faster than usual, this on a timber yacht , any information
Please .
David Lancaster ,
By Allanr529 - 26 May 2015

Hi David,

I have learnt that zinc anodes are designed for tin based antifoul. Copper anodes are needed for copper based antifoul. A lot of copper based antifoul falls off into marinas (making them shallower over time). Copper anodes will normally extend the antifouling life.

Also that stray electrical current can be created by a variety of sources in the boat, including the increasing concentration of salt water in the bilge (due to evaporation of the water) to create a battery, and also because of faulty electrical systems in marinas and in nearby boats in the marina.

There are techniques to use to insulate your boat from outside problems, to minimize problems created in your own boat, and for directing stray electrical current from your boat (especially when starting engines) out into the water via a sacrificial copper anode: rather than down your prop shaft to use the propeller as the sacrificial anode.