Capillary Action of Water and Contaminants in an Air Filled Space

The Problem:  RUST! 

Place a hollow tube into a liquid -- such as water -- and the liquid rises up the tube. The narrower the tube, the higher it rises. This is caused by a phenomenon called capillary action.

When a coil of rolled steel is exposed to moisture, the same effect can easily cause extensive rust damage to the metal. Moisture present at the sides of a steel coil is drawn inwards, trapped between the metal layers.   Result: corrosion!  The same natural action takes place on metal surfaces on your vehicle.

You can easily try the following test yourself with a simple experiment. Take two thin plastic sheets -- the sort of stuff used for laminating ID cards, etc. -- and place one 'nearly' on top of the other. 

Leave about 1" of the bottom sheet exposed as shown above.  Place a drop of water and food color or water diluted ink where the edges of the sheets meet.

Within an hour or so the tiny drop of liquid will spread between the sheets. This shows the nature of the problem of moisture travelling between metals in close proximity and the need for a direct coupling in your electronic corrosion control system for your automobile.