Galvanic protection and through-hull fittings.

[[163233]]

Whilst pondering the aged and decrepit state of some of my thru-hulls, it occurred to me that they're the same material as my prop, but the prop gets a zinc attached whereas the thru-hulls do not.

Should they all be bonded electrically together? Or is it just that you replace them more frequently?

 

[VicS]

Whilst pondering the aged and decrepit state of some of my thru-hulls, it occurred to me that they're the same material as my prop, but the prop gets a zinc attached whereas the thru-hulls do not.

Should they all be bonded electrically together? Or is it just that you replace them more frequently?

Through hulls should be made of a corrosion resistant alloy such as bronze or DZR brass, or be plastic, and should not therefore need the protection of anodes.

It was once fashionable to bond them together and to the anodes but that is now considered unnecessary, incorrect and likely to cause other problems.

Anodes on fixed blade props made of manganese bronze are probably doing nothing useful.

 

[[163233]]

Ah thanks, I guess maybe the anode is more for the shaft then?