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Zinc Anode Protection On Aluminum Hulls

Haul-out-09-245

We’ve just hauled Wind Horse at Berthon’s in Lymington, UK. Time is short, but we will try and share a few photos. This blog is about the sacrificial zinc anode system.

The photo above is one of the two zincs (out of four total) placed amidships. It has now been in the water 3.5 years, for 4400 hours of engine time, and in excess of 45,000 miles of water flow.

There is at least 2/3rds of the zinc left to go.

Haul-out-09-281

This is one of the two zincs on the aft end of the boat. It is a little more used. Some of the factors which affect how these zincs last include:

  • Hull wetted surface.
  • Paint system.
  • Use of an isolation transformer (or non-use).
  • Speed through the water.
  • Zinc size and surface area.
  • Zinc position.

It looks like our spare zincs will stay in the basement for another three years.


Posted by Steve Dashew  (September 21, 2009)

This entry was posted on Monday, September 21st, 2009 at 12:41 pm and is filed under FPB Series Notes. Both comments and pings are currently closed.




2 Responses to “Zinc Anode Protection On Aluminum Hulls”

  1. karel Says:
    January 5th, 2011 at 10:47 am

    It looks like the sacrificial anode is placed on top of a coating. Is this true? How could it than work? There must be a contact with the aluminium substrate in order to enable an electron transport. Could you respond on that?


  2. Steve Dashew Says:
    January 5th, 2011 at 10:56 am

    Hello Karel:
    The zincs are bolted to t he hull, and stand proud, so that both sides of the zinc are active. Electrical contact is made through the bolts.