Sometimes there's a lot you simply can't "know." In a discussion, a dishonest person can use these uncertainties to keep things undecided indefinitely. After all, what is the meaning of the word "is?"

I mention this because I first saw this dialectic (or should it be 'lie-electric?') used back in the 70's, in the 'great aluminum wire debate."
Shown a failed connection, the aluminum wire makers quickly blamed the installer, and the connectors. The devices weren't listed for aluminum. There was no anti-oxidant used. If used, the anti-oxidant was ineffective because it was applied incorrectly. Screws were tightened too much, or too little.
Nevertheless, while still insisting that there was nothing whatever wrong with their wire, the wire makers decided to change the alloy, and limit production to #6 and larger.

Today, an army of representatives are out there, pounding the pavement, extolling the merits of aluminum wire. They are quick to say that the new alloy has over 20 years of field use and testing, proving it to be no more problematic than copper wire. You need not use anti-oxidant. Torque is critical, they say ... oh, and by the way, Greenlee doesn't know how to make crimpers. Their words, not mine.

I say this in preparation for the following pic, provided by Doug Wells:


[Linked Image]


Please note the evidence of heat at the connection that also lacks anti-oxidant. True, we have no way of knowing the alloy of the wire. Nor have we a way to verify torque after the connection is made.
We do have the reference to Canadian rules, requiring the use of anti-oxidant.

I'd say this pic is a pretty good argument for the use of anti-oxidant.