compound to remove this film. (Refer to Avionics
Aluminum is unusual because it forms an
Cleaning and Corrosion Prevention/Control,
electrically resistant oxide film on all of its
NAVAIR 16-1-540.) Initially, tin-plated terminals
surfaces. It has an inherent property known as
and splices are supplied so no oxide film is present.
creep, which makes proper installation of a
Terminals become dirty when stored or excessively
terminal extremely critical. Creep is the tendency
handled. You should clean them by wiping with
of aluminum to flow away from the point of
a soft cloth. Never use a wire brush or any
pressure. Aluminum is softer than copper, and
abrasive method to clean a tinned aluminum
chemically corrosive when in direct contact with
surface.
copper.
One problem found in aluminum wire is
The electrically resistant aluminum oxide film
corrosion by dissimilar metals. This problem
is always present. Therefore, you must either
occurs frequently when aluminum and copper
penetrate or remove it to guarantee a satisfactory
come in contact. As soon as moisture collects
electrical connection by using the specified
Figure 2-11.-Examples of wire identification coding.
2-26
