Also notice where the 2" end of the zinc will end up WHEN it breaks off
in 2-4 months. Pencil zincs have a habit of eroding nearest the nut and
then breaking off (Especially in high flow environments). I have had
decent luck coating the first 1/2" of zinc nearest the nut with paint or
caulk and letting it dry before install.

Lawrence James wrote:
You can not over zinc. But try one of the ones you have to make sure it
will fit.

"Messing In Boats" wrote in message
...

I'm winterizing my 5.7 Mercruiser which has freshwater cooling. The most
important part of this rather simple process seems to be removing two
drains on the manifold elbow things on each side of the engine and one
on the heat exchanger. The latter one has a pencil zinc, the other two
do not.

Would it be prudent to install pencil zinc anodes on those two also? The
other one corrodes pretty quickly in salt water and I'm taking this rig
to the Bahamas, where I don't want all that warm salt water to corrode
my cooling system. What could it hurt?

Capt. Jeff