Barnacles and zincs

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
Don Sargeant

Barnacles and zincs

Post by Don Sargeant »

I had COQUINA's bottom washed about a month ago (she loves it). The diver said I had a great many barnacles on my prop and Dynaplate (surprise? not!). When I hauled her yesterday to my surprise there was very little, if any, new growth -- but the zinc on the Perrynut was completely gone. I am now convinced the existence of a zinc has a lot to do with how much barnacle growth the prop sees. The prop had been carefully coated with Temco outdrive antifouling paint. What does the collective wisdom think about not putting a zinc on the shaft but, rather, hanging a fish over the side?
Don Sargeant
~~COQUINA~~
CD25D #189
Waiting for spring in Greenwich Cove
Stephen P. Marino

Re: Barnacles and zincs

Post by Stephen P. Marino »

I am now convinced the existence of a zinc has a lot to do with how much barnacle growth the prop sees. The prop had been carefully coated with Temco outdrive antifouling paint. What does the collective wisdom think about not putting a zinc on the shaft but, rather, hanging a fish over the side?

Don Can't answer your thoughts on the fish but the use of a sink on a hull where all the underwater metal is Bronze and you are at an out water mooring miles from any stray currents with your battery in the off position the addition of a zinc creates an electrical cell. This zinc will just destroy itself. Next time just leave the Perrynut off.

Stephen



s.p.marino@att.net
Warren Kaplan

Re: Barnacles and zincs

Post by Warren Kaplan »

I had a horrible problem with prop barnacles this year. My yard manager said they were going crazy with the problem. EVERYONE in our area had bad fouling. He said without a doubt a zinc present near the prop leads to worse fouling than without a zinc. He said that some people in the past have chosen to leave the zinc off the shaft. It helped quite a bit for those sailors. Of course there's a big trade off if you do that. We all know what that is. He's not recommending leaving the zinc off. He's just saying what others have chosen to do.
He said that the commercial boats in our area don't usually get the problem too badly because they are in use everyday and the barnacles never get a chance to get a good "grip" on the prop before they are spun off each day. Our boats, on the other hand, by and large sit idle during the week and if conditions are right, the barnacle have a field day.
Unless the paint companies or the engineers come up with a way to get rid of the barnacles, they'll probably be like cockroaches! Here, and a pain in the ass through all time. My solution...A diver. After I had to get towed this year because of horrible barnacles, a diver cleaned the prop and bottom for $65. What a difference!! I've decided that when the water starts to warm up, I 'll send him down once a month. That will mean two, maybe three times a summer. A helluva lot cheaper than the tow cost me. And the boat sure sails better too.

Warren Kaplan
Sine Qua Non
CD27
Oyster Bay Harbor, NY



Setsail728@aol.com
Post Reply