I am often asked if anodes
'work'? I believe they do, but only if properly fitted.
Firstly, the bilge keels
can be simply protected by bolting a pair of disc shaped Zinc anodes on, back
to back. Brush with a wire brush every spring and they aught to last years,
especially if you have epoxy coated your keels in the first place.
(Assuming you also troubled to have them galvanised!) Mine have been afloat
every year bar one, since 1990. the keels are in good order, no rust at all,
the epoxy has been replaced once in that time, so have the anodes.
The main anode, note it is
fitted to the hull with the broadest part forward, for least water
resistance. It is also wired to the engine and stern gear, internally. An
anode lasts about 5 years then, when it is just more than half wasted, I
replace it. What does it protect? Well for one thing the underwater
steelwork near it, the rudder bearing and skeg extension, but also the prop
and stern gear. That has all remained in perfect order since 1990, for
minimal cost. Well worth the effort.
To ensure I had the
correct amount of protection, I contacted Duff's, the specialists and they
guided me with simple instructions, seems to have worked.
Bilge Plate Anode