Maintenance
26
Protection against corrosion - Zinc anode
When at least two different kinds of metal are immersed
in seawater, polluted water or water with a high mineral
content, a chemical reaction occurs and an electrical current
is established between the metals.
This electrical current leads to the metal that is more active
from a chemical point of view, or more anodic metal being
eroded. If this is not controlled, this galvanic erosion can
seriously damage the parts and propulsion system that are
exposed to water.
In order to protect the engine and the seawater cooling
system from corrosion, the engine is
fi
tted with two sacri
fi
cial
anodes located on the end cover of the exchanger.
To remove the anodes
• Let the engine cool down
• Close the seawater intake valve
• Drain the seawater system
• Remove the set formed by a cap, a seam and the anode.
Remark:
Remove the deposits from the surface of the anode
using glass paper before determining the level of erosion. Do
not use a soft steel brush as this could leave deposits that
are likely to speed up corrosion.
If more than 50% of the anode has been used up, replace
both it and the seal.
I
Attention! :
Screw the anode cap back on tightly and do
not forget to re-open the seawater intake valve.
