I've googled this already and found many people saying that Noalox is only for copper to aluminum connections. I know that Noalox stands for "no aluminium oxidation" but brand names often change meaning from their origins over time. I've also seen people claiming their bottle says it is only for aluminum to copper, while other people say their bottle also says it can be used for copper to copper.
Well, my bottle doesn't say anything about aluminium or copper – it just says it can be used for improving and protecting electrical connections.
Since I am replacing some outdoor outlets and switches that are about 20 years old and mostly rusted to hell, I thought it might be a good idea to put some conductive grease on the contacts for longevity's sake. (I am already replacing all outdoor wingnuts with weatherproof wingnuts which I think also have some kind of grease inside).
It seems Noalox is the only thing my local Home Depot carries for this purpose (or the employee is ill informed) and I'm on a tight schedule so I can't wait for something like Penetrox E-8 to arrive. I know there are concerns about Noalox actually potentially reducing connectivity, but my main concerns is simply ambient humidity and condensation causing corrosion in the contacts over time.
My feeling is that Noalox will do a decent job in this regard, and so even if there is a 1-5% cost in connectivity, there is a 100% improvement in anti-corrosive longevity. Am I wrong? Anyone else care to weigh in?
A related side question: is it a crazy idea to use dielectric grease on the prongs of an outdoor device that is essentially permanently installed and will be plugged into an outdoor receptacle, potentially for years on end? Or is there a better grease for this? Or better nothing at all?
I know there are concerns about non-conductive grease in high voltage applications since they might actually reduce conductivity, but considering most devices are designed for 110V and my mains is actually more like 124V, I don't see that being a huge issue. Especially since these outdoor devices aren't high amperage.
Best Answer
I have used dielectric grease for years in so many applications. For mains voltages is is primarily a non-conductive corrosion barrier. In that sense, any non-conductive grease will do. Electrically, the original metal-to-metal connection is maintained because corrosion is reduced. You can use it liberally around connection points because it does not conduct.
Noalox sems to contain zinc dust in a plastic grease matrix. I'm not sure how conductive it may be at mains voltages, but I would apply it only at the specific connections.