Over the years we have heard many times the zinc on the Max-Prop feathering sailboat propeller erodes too quickly and that it just burns out at the screw while there is a lot of zinc left.
Why do these zincs erode so quickly?
The primary reason for this is lack of contact between the zinc and the propeller. If when installing the zinc you clean the flat surface of the zinc and the back of the propeller you will have good contact between the zinc and the prop, and the zinc will last much longer. If you just install the zinc on to the propeller without cleaning the only contact is between the zinc and the propeller is the screw, and yes it will burn out around the screw. So cleaning is key.
With that said, since we don’t always do what we are told, we have designed a new zinc to help. The new Max-Prop zinc has a metal ring molded into it. This metal ring goes around the entire diameter where the screws attach the zinc to the propeller. This ring disburses the electrical current through the entire zinc giving it a much longer life.
Even with the new zinc be sure to clean both surfaces before installation and check your boat often, especially if you are in a “hot” marina.