AFL's No. 2 Electrical Joint Compound (EJC) is the recommended compound providing efficient and trouble-free service on aluminum-to-aluminum and aluminum-to-copper connections. If No. 2 EJC is kept in a dry place, it has an infinite shelf life.
No. 2 EJC has the lowest electrical reistance on flat surfaces because it is a grease type medium that dissolves the oxide on connectors. The nature of the oxide removal is not harmful. Unlike other compounds of its kind, No. 2 EJC creates a light surface etch with no deep, localized attack.