Why do some anodes bubble?
QWhile cleaning around the newly fitted anodes on my recently reblacked 55ft boat to remove mud/algae growth, I noticed that bubbles were being released from the surface of at least one anode. Is this a normal occurrence or have I got some incipient electrical problem somewhere? BOB HALLAM, via email
On the face of it this sounds like electrolysis of water and that implies that the anode is doing its job, but it should not be that fast. However, if the canal water has been mixed with seawater, anodes will fizz. It is scary looking at them on a sunny day in Liverpool docks.
If you have a shoreline, get either an isolation transformer or galvanic isolator, because your anodes might be protecting a number of other boats via the earth cable.
Keep an eye on the anode to judge its wear rate and also talk to a specialist manufacturer like Duffs (mgduff. co.uk) in case the canal is full of brackish water, in which case a different anode metal like zinc or aluminium might be better.