I don't think there has ever been a bad copper shortage, but sometimes copper prices get too high. When this has happened, it has been more ecomomical to use aluminum for wire.

Unfortunately, the aluminum producers' association has pushed the economics of using aluminum wihout adequately educating the users and trades about the pitfalls and pre-cautions needed to allow it to be successful in many applications.

Some piano builders were convinced to change from making the plates from time-proven cast iron to aluminum. This change was primarily to save weight. Pianos have to be shipped long distances and weight reduction saved a lot of dollars in shipping costs. The plate in a piano bears the tension of all the strings which totals 30 to 40 TONS! Soon after adopting plates made of aluminum, the plates would crack under the stress of the strings. When a plate cracks, the piano becomes junk. It will never be possible to have it in tune and the whole think must be taken to a land fill. That is quite a price to pay for experimenting with aluminum.

With electrical equipment, aluminum is now used with good success after the industries were properly educated in its use. Most of the original problems were with the methods of connecting aluminum. That is to say, the problems were in the connections and not in the conductior itself. It was found that wire made from pure aluminum did not work like wire made from pure copper. The aluminum wire would fatigue and break after bending it two or three times. This problem was solved by alloying small amounts of other metals with the aluminum.

As for the connections, the same connectors and methods used with copper wire always resulted in connection failure when used with aluminum wire. This what the aluminum wire producers did not adequately educate the electrical industry about at the outset. All of these problems have now been solved with properly engineered methods and materials for making aluminum connections. In house wiring, there are wiring devices (the receptacles and switches) that are now made specifically for use with aluminum wire. They have screw heads that are completely different from those that are for copper. They are plated with indium metal which is compatible with aluminum wire. (Has anyone ever heard of corrosion problems caused by mating non-compatible dis-similar metals together.) The connection has a much greater surface area to make with the wire which avoids cutting the wire. It is made so that it bites through the aluminum oxide.


All of the small lighting and convenience outlet branch circuits of 15 amps and 20 amps use number 12 and number 10 a.w.g. aluminum wire in place of the number 14 and number 12 a.w.g. copper wire. For larger circuits using wire larger than number 10 a.w.g., most all equipment is now made with connection lugs that are compatible with both aluminum and coper wire. When aluminum wire is used on these lugs, the stripped ends of the wire are supposed to be coated by the electrician with the special grease that is made for aluminum connections. The grease has many trade names such as Penetrox or CuAl-aid (sounds like Cool Aid.) This grease prevent or retards oxidation of the exposed aluminum wire. It also has metal particles mixed into it which bite through the aluminum oxide of the lug and the wire.

In short, all of the problems with using aluminum electrical wire have been solved. It should be noted that copper wire connections can have all of the same problems that aluminum wire connections have except that they tend to be less severe. In other words, copper wire is more foregiving than aluminum wire when improper methods are used or when connections are loose.