[C320-list] Clean Propellers

[Warren Updike]

Someone in our marina conducted a season-long test of various anti-barnacle
strategies. It was not a scientific or controlled study; but, for what it's
worth, here is the result:

Properly prepared, spray on several coats of a zinc primer, heavy on the
center of the prop, lighter toward the edges. You can find such a product in
a home store labeled as containing 90% (or better) zinc.  This is the
cheapest solution if it works for you. Properly prepared means a thorough
cleaning of the prop including sanding until clean and smooth. Since the
surface corrosion begins immediately, is best to wipe the surface with
acetone or such immediately before painting.  Perhaps someone with real
metal experience can suggest a better method.

My barnacle experience (Chesapeake Bay,) is that they collect mostly around
the hub and shaft. If you don't use your boat regularly, you will have more
and they will cover more of the blade. When I have painted the prop with
bottom paint, I've found that prop friction in the water usually wears off
most of the paint on the outer portions of the blade.

Warren & Pattie Updike
1994 C320 #62 "Warr de Mar"



-----Original Message-----
From: Joseph Aberdale [mailto:summerwind3 at comcast.net] 
Sent: Wednesday, October 27, 2010 10:57 PM
To: C320-List at Catalina320.com
Subject: [C320-list] Clean Propellers

Hello To All,

The prop on my recently hauled C320 had a lot of barnacles (new  
owner).  I just finished reading Nigel Calder's article on this  
problem in the Sept. issue of Sail Magazine in which he mentions  
several products to remedy the problem.  Does anyone have a favorite  
product among these?  Do you recommend painting the prop with bottom  
paint first before applying one of these products?  Mr. Calder's  
research shows that fuel consumption increases 50% with "with just a  
few barnacles on the propeller."

Thanks very much.

Joe
#908