Electrolytic corrosion is corrosion caused by current from an external source, such as a vessel’s battery or the shore power supply in a marina. This current is known as stray current. Electrolytic corrosion can cause serious damage to a vessel’s hull, underwater metallic components, coating systems and anodes.
If an underwater inspection reveals unusually rapid depletion of anodes or serious localised damage to the coating, this may be an indication that the vessel has been or is currently being subjected to stray current.
In addition to a comprehensive inspection and possible repair, identification of the cause of the stray current is critical. This can be achieved using a reference electrode, such as a Rust Seeker to narrow down the source of the stray current.
Alternatively, a specialist, such as a corrosion engineer, may be required to assist with the investigation.
Welding in a Marine Environment
Sea water has very low electrical resistivity. If any electric welding is undertaken whilst the vessel is in sea water, it is essential that the welder’s earth be located immediately adjacent to the job. Any other location may cause stray current corrosion (at the rate of up to 10Kg /amp/year).
Leave A Comment
You must be logged in to post a comment.