My main comment before I get distracted... is: Why would anyone want to put an insulating paste in an electrical connection when a conductive material could be used instead?
====================================== @ Lawrence: dielectric also means it supports electromagnetic fields, which more of an RF thing. Not everything that is greasy is dielectric. But it definitely means not conductive. As far as grease getting squeezed out, I have my doubts about that. I am certain there is a film left behind. On switch contacts where the forces are much more concentrated, oily, greasy films don't get pushed out, the get burnt away by the heat of the current passing through asperities (from Merriam -Webster *:* a tiny projection from a surface), and due to the constriction resistance which actually makes little microscopic rings of fused metal. On a switch these burnt products are solid and become polymeric which does interfere with the electrical connection. Is this pertinent to a battery connection? I don't know, but it might be. I am sure the business about surface asperities and constriction resistance is the same. I notice Roland is very concerned about joint resistance. ===================================== Drifting towards NoAlOx: Tin plated connectors with a sliding contact actually do count on the tin oxide coating getting pushed away and the formation of a gas-tight connection. However, you do not see aluminum contacts on connectors, because the Al oxide and underlying aluminum are too hard for this to work. Not to mention you can plate Al onto copper and brass. ============================ (This is sort of OT for dielectric, but I did some hunting around, and some one might be interested) I get what NoAlOx is and I have looked at the website too (no real proof of claims there that I could find). They only mention prevention of galling and seizing of conduit joints, I didn't see anything that says put it in the electrical path. Here is a good search string: noalox site:www.idealindustries.com >From a product page: - Anti-oxidant - Reduces galling and seizing on aluminum conduit joints - Suspended zinc particles penetrate and cut aluminum oxide - Carrier material excludes air to prevent further oxidation - Improves service life of aluminum electrical applications Anti-oxidant - Maybe of some metals, but not aluminum. You simply cannot find un-oxidized aluminum. Conduit joint, OK. Not what we are all about here. Zinc particles penetrate and cut aluminum - show me, and show me it matters. I see the MSDS also lists sand as a component. I believe sand will cut. Is zinc harder than aluminum oxide? I think not. It would be hard to sell grease with sand in it and get people to buy it even if it worked. A little zinc powder might make it more palatable and would still be cheap. "Excludes air to prevent" does not mean it prevents oxidation of aluminum - they wish, you really have to prove that to me. If there is any oxygen entrained in the paste, you can bet it gets to the aluminum and oxidizes it. Improves service life - better than other anti seize? With a battery connection, how much is going on that you are worried about service life? How many tighten and loosen cycles are we talking about. Two? Ten? And, grease and oil hold and trash that gets in it, and that could also effect service life. For a field repair I can imagine a dry joint would be better. I looked at every page at Ideal Industries website and there were no white papers, articles, product use instructions, nothing that elaborates on the basic bullet points they make. I think NoAlOx may have some merit, but this is pretty much anecdotal, seems no one who uses it reports it is doing harm. ====================================== I have not found the electrical code reference that calls for NoAlOx. (someone else mentioned this in another thread) I did not see anything on the site about use with round aluminum conductors. But the substantiate nothing at all. So... ==================================== Please don't take any of this wrong. I am a born skeptic. I am always looking for logical errors, and so called common sense that isn't sense at all. It is fun and educational. I am always willing to consider real proof, but not marketing hype. On Mon, Jan 13, 2014 at 7:04 PM, Lawrence Harris <[email protected]>wrote: > Just looked up NoAlOx. > > Improves service life of aluminum electrical applications > Reduces galling and seizing on aluminum conduit joints > Suspended zinc particles penetrate and cut aluminum oxide > > Seems it's not so much that the zinc makes it conductive as it helps break > through the non conductive aluminium oxide layer and so improves the > conductivity. So for aluminium connections it might be both useful and > important to use something like this. For other situations (similar > metals) just using petroleum jelly on a clean joint may work just as well; > if the joint is tight enough the grease should be squeezed out and so does > not interfere with conductivity only acts to exclude air and water reducing > the potential for corrosion. > > While a dielectric is non conductive it does mean more than that, it's a > property of an insulator and some have better dielectric properties than > others. > > Lawrence > > On 2014-01-13, at 11:27 AM, Michael Ross wrote: > > > Dielectric essentially means non-conductive. The whole point of NoAlOx > is > > to enhance conductivity and it contains zinc powder - some one said (I > > haven't looked into it much). > > > > Theoretically, why would you want to put a non-conductive material > between > > two current carrying members, when a conductive grease would do just as > > well at protecting from moisture? I see no reason not to smear > dielectric > > all around outside, but it might end up in the current path just the > same. > >SNIP > -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, "The summer day." To invent, you need a good imagination and a pile of junk. Thomas A. Edison<http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell (919) 513-0418 Desk [email protected] <[email protected]> -------------- next part -------------- An HTML attachment was scrubbed... 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