SailNet Community - View Single Post - Using Bottom Paint on Brass Propeller
View Single Post
  #18  
Old 04-24-2013
73Morgan 73Morgan is offline
Member
 
Join Date: Dec 2012
Posts: 45
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
73Morgan is on a distinguished road
Re: Using Bottom Paint on Brass Propeller

Quote:
Originally Posted by Maine Sail View Post
While some props are NiBrAl (nibral) most are manganese bronze. The bronze part of manganese bronze is a little misleading because most props contain upwards of 35-40% zinc.. Applying copper bottom paint can destroy them..

This prop was fine for 25 years unpainted. It was painted with a copper bottom paint and in less than one year was dezincified and destroyed.
Main Sail, thanks, great post.
Bronze has zinc in it, wow, that explains the electrolysis concerns.
Scary bunch of pictures, internal damage. I will change my ways, hope it is not to late.
You just indirectly explained why it is a good idea to have a zinc on the prop shaft. Been changing the zinc on the prop shaft every year. That probably helped a little??

Last edited by 73Morgan; 04-24-2013 at 12:08 PM.
Reply With Quote Share with Facebook