If you own a wooden boat, this article by Chris McMullen and Baden Pascoe is essential reading: "Loving your boat to death".
From the article: "Apart from fresh water ingress, electrochemical destruction of hull timbers is the biggest threat to our classic fleet" Thanks Chris and Baden for getting the word out.
When we first bought Arethusa, her rudder and keel shoe were steel. She had two zinc anodes. There was electrochemical damage (caustic soda that eats away at the kauri) around the rudder stock and powdering on the shaft log.
The pics below, show the work we've done to ditch the steel and have all similar metals (bronze and SS) underwater, and remove our zinc anode completely.
A huge thank you (as always) to shipwright John Gander, for all your incredibly skilled work.
Damage around the rudder stock, horn timber and cheeks.
We replaced the steel rudder with one John made from purple heart with aluminium bronze forks.
The soft wood was removed from around the rudder stock and new kauri glued into place. The two cheeks and their galv fastenings were removed and replaced with purple heart and copper bolts. You can read about that whole job here.
Horn timber repaired, two new purple heart cheeks fitted.
While the new rudder made an big improvement, we were still getting a white powdering around the shaft log coming from the steel keel shoe and zinc anode set up.
In 2023, we decided to remove the steel keel shoe and replace it with a bronze one, and do away with our zinc anode completely.
Shaft log "powdering" caustic soda.
The set up we replaced - steel keel shoe and zinc anode
New aluminium bronze shoe
Removable base will make rudder removal easier.
Protruding channel filed with cement
Job done, anode removed permanently.
One year on, pleased to report, the timber around the shaftlog is no longer producing caustic soda, a total win for Arethusa's timbers.
