Copper Grease and Batteries

[LowGear]

I've searched for the thread where you tried to edumacate me about using copper added anti-seize grease to help control the posts, clamps and cables on battery systems and I simply cannot find it. 

Anyway; Do I brush the stuff on the post and inside the clamps before I assemble or after?

Casey

[mike90045]

neither.  for battery terminals, plain petrolatum jelly (Vaseline) or anti-corrode terminal post spray is good.  I use the copper grease (McMaster-Carr catalog) on my cables before crimping the lugs.   I'm just afraid the copper grease will corrode out too quick on the posts which always seem to get acid on them.  I use copper grease bolting lugs together, or in splice blocks.

[BruceM]

+1 for Mike's recommendation.

[quinnf]

The reason for the copper is to maintain electrical contact.  A friend many years ago who was working on a nuclear power plant told me they specced the copper grease on all threaded fittings.  On battery terminals you want electrical contact; grease by itself is an insulator.  I've been using the same can for over 30 years on all my vehicles, friends' vehicles, ex-wife's cars (we're still friendly) and never have seen any corrosion.  When a terminal is removed from a post the copper is bright and shiny. 

Quinn

[Ronmar]

I use it in ground and bond applications exposed to the weather in saltwater marine applications and I have never seen it corrode either.  Wipe a little on the post and champ the lug down onto it.  It should help keep good contact between the conducting surfaces.  Petroleum jelly is great as an overcoating to isolate the lead from the atmosphere and cut down on oxidation/corrosion.

[BruceM]

I'm not so sure about the copper grease.  I tried measuring it's conductivity via ohm meter, and it is totally NOT conductive, not even slightly.  (There is conductive grease, but it's very expensive, and this stuff is NOT conductive.  It may have other anti-seize or anti-corrosive properties that make it great, but it just isn't conductive, not even in the megaohm range.

[Ronmar]

The stuff I use is very conductive.  Goes under the name "coppercote" if I recall correctly.  It is closer to a liquid than a grease...

[quinnf]

Bruce,

I think there's a good reason for your observation.  The material is intended to be used on threaded fittings.  The copper particles in the can are randomly oriented, and few are touching each other because the formulation contains suspending agents which keep the copper particles from settling in the can.  But smear a dab on a metal surface, e.g. a threaded stud, and screw on a nut, and most of the material will squeeze out leaving a thin layer of the metal particles smooshed flat (smoosh is a technical term) between the metal surfaces in the threads.  Same thing happens between a battery post and the clamp. But though lead is much softer than steel or lead and won't smoosh the relatively harder copper particles, the copper will bridge the adjoining metal surfaces and provide a conductive pathway.  Additionally, it excludes moisture and vapors which get in crevices and cause the lead to oxidize.  

Loctite makes a variant which is black and contains graphite as well as copper.  I use it as a general anti-seize for threaded fasteners where I don't care so much about conductivity.  The stuff that I got a can of which was used on the power plant was Koprkote, a bright copper colored paste.  It looks like it's still available from MSC  
http://www.mscdirect.com/FlyerView?pagelabel=3068&search=01461839&contentPath=/sales-catalogs/big-book

The page contains a bunch of similar products.  The can of Koprkote I was given a can of in 1980 by a friend who was working on the Nuke power plant is a bright copper colored grease.  Probably similar to the Jet-Lube SS-30 Pure Copper Anti-Seize.  

Quinn

[BruceM]

OK, next year when I swap out my battery bank, I"ll give the copper grease a try.   Thanks Quinn!