Does CD31 prop shaft require a zinc

[RAJ]

I am doing a bottom job soon on my CD31 - noticed the exposed prop shaft is relatively short - does the shaft require a zinc?

thanks

Russell



rajarch@bellsouth.net

[Matt Cawthorne]

Russel,
The zinc is only required if you wish to keep your prop from disolving. If your prop is brass, the disolving involves all of the zinc leaving the brass and the remaining propeller becoming very weak.

What is normal for Cape Dory installations is to put a zinc on the end of the shaft. There are two types. One is a 'Perry nut' which, I believe but am not certain, is a nut made of zinc with a nice hydrodynamic shape. The other is found in most boating stores is a brass or bronze nut which has a zinc which attaches to it. Each year you replace the zinc and not the nut.

You may be able to find a shaft zinc which is small enough to fit directly on your shaft.

I'll bet that if you had no zinc on your shaft that you had a barnacle free prop.

Matt

I am doing a bottom job soon on my CD31 - noticed the exposed prop shaft is relatively short - does the shaft require a zinc?

thanks

Russell

mcawthor@bellatlantic.net