Fast corroding zinc anode

Discussions about Cape Dory, Intrepid and Robinhood sailboats and how we use them. Got questions? Have answers? Provide them here.

Moderator: Jim Walsh

Post Reply
J&P
Posts: 19
Joined: Jun 16th, '06, 20:47
Location: CD28: Fairhaven, MA

Fast corroding zinc anode

Post by J&P »

I replaced the prop nut zinc anode on our CD28 this off season. After being in the water for six weeks I noticed heavy corrosion.

Questions:

1) What would cause such quick corrosion? The boat is on a mooring in Buzzards Bay more than a hundred yards from a dock.

2) As an interim measure I was thinking of attaching a hanging zinc overboard while moored.
  • a) What is the best place to attach the hanging anode? I read the backstay works well but want to confirm since this seems so easy.
    b) Given the simplicity of a hanging anode (no mid-season replacement or checking to see if it fell off) why do they seem to be less popular than the prop attached anodes?
This is our first full season with the boat so I have little prior experience with rate of corrosion. There are no known electrical problems.
Tim Mertinooke
Posts: 177
Joined: Feb 5th, '05, 18:28

Post by Tim Mertinooke »

A guy at my yacht club was having a similar problem on a Sabre 38 so he put a zinc fish overboard and it seemed to have stemmed the problem. It could be that you are leaking electricity yourself. Take a multimeter and start touching stuff (shrouds, stantions, seacocks, etc.)

On a bright note, at least it's your zinc and not your propshaft. Maybe you are one of the lucky ones who has to dive down halfway through the season to replace the zinc. :wink:
CD26 #52
"Odyssey"
Post Reply