If your housing is made of aluminium it can corrode due to electric currents made by your camera or your lights.
On ships, Zinc coating is being used as an efficient solution against Marine and Offshore corrosion.
The hull of a ship is the watertight body that is exposed to water, just like your housing is to your camera.
To protect the hulls, the shipbuilders put pieces of Zinc on these hulls. The Zinc components used on ships are called “Sacrificial Anodes”.
They are made of metals that are more reactive than the material used for the ship’s body and systems. So as such, they shield the ship’s body and systems while the ship stays protected.
Why does this happen?
Zinc is used because it has a higher voltage in the water so the current is more inclined to flow from it than from the propeller. To complete the electrical circuit, Zinc components are connected to the items they are intended to protect. Zinc is bolted right to the shaft of the ships hull – and the same way it needs to be mounted directly on your underwater housing.
So to help prevent galvanic corrosion of the housing simply install in onto a part of your housing that is exposed to water.
Most housings already have these anodes mounted.
Remember, the Zinc material will erode sacrificially over time during deployment.
So you might need to exchange it after some years.
