Remember that in almost any connection there is always an oxide layer. The purpose of the sanding is to remove enough of this so that a reasonable pressure between the wire/strap and the connection can break through this layer and form a gas tight connection. The grease is just there to keep moisture out, fill any small gaps and prevent surface corrosion. The the added zinc will likely take up any remaining oxygen and further prevent corrosion for a time, as far as I know it does not contribute to the conductivity of the connection.
Lawrence Harris On Jul 31, 2014, at 9:43 AM, Michael Ross via EV <[email protected]> wrote: > Thanks for the level-headed reply Bill. > > You described three functions - grease excluding moisture, zinc as a > sacrificial anode, and somehow removing aluminum oxide by sanding. > > Here on this list I have been persuaded that the grease excluding moisture > is likely a good idea. Pick one that won't dry or bake out. I can't for > the life of me figure out why a highly resistive dielectric grease > (mentioned by others) is a better choice than a conductive grease...noalox > is essentially a conductive grease given the Zn content. > > If you really do exclude the moisture then the zinc would be redundant, > seems like. > > With aluminum, you just cannot expose bare un-oxidixed metal, it is not > possible to do this, so I am not happy with the sanding idea. The sanding > has to be helpful on some other basis if it is indeed helpful. > > Be interesting if someone has compared greased un-sanded to greased and > sanded. > > I suppose if you used really fine grit paper you might actually improve > intimate mechanical contact, but I have my doubts. > > I admit I have not yet used any cells with aluminum terminals. One pack > has all the cells welded to stainless steel strips, the other are what look > like stainless or nickel plated something, stamped and formed with a tapped > holes (38120 size cells). I have a group of used Thundersky cells, but I > have not used them yet. > > > On Thu, Jul 31, 2014 at 11:17 AM, Bill Dube via EV <[email protected]> > wrote: > >> Here is an article describing how to make aluminum to copper connections, >> and when to use (and when not to use) oxide inhibiting paste: >> http://www.stabiloy.com/NR/rdonlyres/AD9F20D3-FA28-4662- >> A013-A154C569435C/0/AluminumBuildingWireInstallationandTerminations.pdf >> >> The cell manufacturer gives no guidance as to the use of oxide inhibiting >> paste, so one must try it both ways. I tried it without Noalox, and then >> with Noalox. >> >> I have installed cells without the light sanding and paste, and the >> connections were unsatisfactory. They got quite hot. The car performed >> poorly and had limited range. The cells would not balance well. I then >> performed the "lightly sand and apply Noalox" procedure, and did nothing >> else, and all those issues vanished. No additional torque. No added or >> removed components. No change whatsoever than to lightly sand and to add >> Noalox. >> >> Some time later, a friend had identical issues with his conversion, and I >> recommended the same treatment. He performed the "lightly sand and Noalox" >> procedure, and it cured his issues in the identical manner as it had cured >> mine. >> >> I now routinely use Noalox and I have not had any high resistance >> connections. >> >> The Noalox prevents galvanic corrosion between the dissimilar metals in >> the terminal by excluding moisture. Additionally, it has zinc particles >> that provide a sacrificial anode, further guarding against corrosion >> between the copper, aluminum, and the stainless steel bolt. In theory, this >> is what one does to prevent galvanic corrosion. It also appears to work in >> practice as well. >> >> I have actually done the experiment, and the results agree with theory. If >> anyone else has performed a similar experiment and had contradictory >> results, then I would enjoy hearing about it. >> >> Bill D. >> >> _______________________________________________ >> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >> http://lists.evdl.org/listinfo.cgi/ev-evdl.org >> For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/ >> group/NEDRA) >> >> > > > -- > 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... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140731/dc0ba8a0/attachment.htm> > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA > (http://groups.yahoo.com/group/NEDRA) > _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
