Electrolysis Destroys a Shaft

2010 May 5
by Chris Brown
Shaft Damaged with Electrolysis
Shaft Damaged with Electrolysis

A simple prop change on a sailboat turned into a major surprise for the owner.   All of the zincs were gone by the time it was hauled into our yard.  The Maxprop had badly damaged prop blades due to electrolysis.  Once the prop was removed the Spurs cutters showed similar damage. 

It was not until the Spurs were removed that we could see the true extent of the electrolysis damage on the shaft.  Over 30% of the shaft was gone just behind the prop taper.  This is one of the worst cases we have seen in quite a while.  This owner was very lucky to still have his Maxprop attached.
All vessels should be inspected by a diver at least once a month to make sure all of the zincs are in place and doing their jobs.  This is a small investment compared to the damage electrolysis can cause.
A lost prop is costly.  However, there are countless stories of electrolysis damaging a thru-hull fitting to the point of failure causing a vessel to sink.
No comments yet

Leave a Reply

Note: You can use basic XHTML in your comments. Your email address will never be published.

Subscribe to this comment feed via RSS