Anti-Corrosive-Zinc-Paste for Electrical Connections                     Updated Feb15, Dec08 R. Kwas          


Background:  To keep getting trouble-free service from electrical connections in our vintage vehicles, is pretty important.  To help with this, I highly recommend the use of Anti-Corrosive-Zinc-Paste (ACZP, is my generic term).  This is paste of conductive Zinc particles in suspension, and should not be confused with insulating dielectric grease, which is often also recommended (maybe because the word dielectric has the word "lectric" in it, so it must be good for 'em...WRONG!), but which is not the best solution.   Why anyone would want to apply an insulating grease on a place where you want a good electrical connection is beyond me, because if this insulator actually got between the contacts, it would be degrading the connection, whereas when ACZP gets between contacts , Condition B protection is taking on...ACZP has two distinct advantages as it acts both microscopically as a sacrificial anode and superficially, creating a Gas-Tight-Joint (GTJ) to protect electrical connections....use it on new connections and when restoring old ones!     

Zinc containing anti-corrosive pastes only protect an existing good electrical connection ...they will NOT improve a poor old connection, so they sure as hell wont improve anything if slathered on the outside of a poor connection.  Disassembly and a good cleaning are required first.  This may be as simple as pulling off a 1/4" spade type terminal, and abrading any oxidation from the spade terminal (squeezing the mating terminal to restore a decent spring action...or better yet, and to be sure, replace the entire connector...apply paste to wire after stripping and before inserting into crimp - OPTIMAL!), applying the paste onto the flat terminal, and reinstalling the connector.  On more permanent connections such as the heavy current battery cable connections of the starter/solenoid, this requires a slightly more involved disassembly, but a cleanup to shiny metal is again required, then application of paste, and reassembly...the forces of the fasteners will displace the paste around the joint...excess can be wiped away.

Formulation viscosities range from Burndy's Penetrox, a thick paste with very firm, almost putty consistency, which I have found will stay where it is applied - even overhead or at elevated temperatures, to Ideal's much thinner Noalox which totally separates in the container, needing to be remixed before use...disappointing!...I much prefer the's consistency does make it very difficult to coax out of the plastic squeeze bottle.  I wound up cutting open the half full bottle and repackaging it to a much easier to use flat tin container.  A toothpick or similar serves as a throw-away pinpoint applicator.  More recently, I have discovered Ox-Gard by Gardener-Bender, and had a response by Ideal promising to improve the characteristics of their product. 

LINK TO:   Simple Corrosion/Oxidation vs. Galvanic Corrosion and Burndy's Penetrox A vs. Ideal's Noalox vs. Gardener-Bender's Ox-Gard

LINK TO:  Sw-Em ACZP Droop Test  

Many different styles of connections are used on cars, some of these can be considered to be of a "high contact pressure design" (1/4" push-on, all bolted) but some of these connections must be considered a "low contact pressure design" (544, 122 and 1800E&ES Euro-Fuses, and especially the 3AG fuses used on the 1800; bayonet lamp sockets).  In the "low contact pressure design" case, displacement of the grease from the current carrying area is not assured because of the low pressure, and certainly not as good as it might be, which can in fact make for a poor path for the electrical current, so this is NOT a good place to use the dielectric grease.  Anti-corrosive paste, is, on the other hand perfectly suitable for ALL low voltage electrical connections (not High-Voltage Ignition)!  There is no need to think about what kind of connection we are using it on!  That is why I make the following statement.

Suggested uses for electrical anti-corrosive paste:  Just about all automotive electrical connections that one wishes to get long-term, uninterrupted service from...including battery, chassis strap, fuse to holder, lamp to socket, antenna connections...etc.  As a matter of fact, if anyone can come up with an automotive connection where it would not be suitable, I'd love to hear about it!


Conductivity Test: 
Ohmmeter probes in a dab of ACZP show no conductivity!

Related Excerpt from a Forum Thread: 

"  product (ACZP) compatible with all electrical metal interfaces?  For instance I believe the battery post contacts would not be aluminum to same or to copper. Is there any interface where this product would be harmful."

My Response:  "There is (thankfully) no aluminum used in the electrical systems of our cars, only copper (wiring and some terminals), brass (terminals), tin (terminals and plating on some copper terminals), steel (studs for connections for ring terminals and chassis), lead (bat post and clamps)...I think that lists most if not all of them...

ALL of these metals are compatible with and will benefit from the long-term protection ACZP formulations give on reassembly (connection surfaces should be clean and free of corrosion/contamination first!). Ox-Gard and Penetrox A are suitable. Noalox is not." 


ACZP is actually non-conductive!  That's because the conductive zinc particles...more like zinc dust really, are suspended in non-conductive grease, and so are not in contact with each direct conductive path actually exists across a blob of it (see above) itís pretty benign stuff at the low voltages present a vehicleís electric system, and should not be considered to be making electrical contact or carrying any current...and thatís why lathering it onto a connection without first separating and cleaning will only externally cover the connection and not take full advantage of the chemical benefit of the zinc particles...

When in place between and around two contacts which have mechanical pressure pushing them together, the benefits occur at the microscopic level.  Three distinctly different conditions take place.  To understand and appreciate the advantage, a finer inspection of these conditions is presented here:

ACZP at work!

Detail of ACZP at work!

Condition A - Direct Contact of Base Contacts.  (Great...thatís the whole point!)...not much more needs to be explained here!  These areas are in fact, the only current carrying areas!  Without them, weíre in the dark!

Condition B - Base Contacts are Bridged by Conductive Particles:  As the two contact surfaces touch each other either by sliding under substantial contact force (like the push-on connector shown), or by forcing the surfaces together (ring connector where a nut provides the high compression force, or even bare wire in a crimp), some of the particles are sheared or compressed, bridging the two surfaces.  In this case, the zinc particles, being made of one of the least noble metals due to itís low station on the nobility chart , (see:  Galvanic Chart), and most willing to give up reactive ions, then act as zillions of sacrificial anodes which give up their ions, effectively passivating the area on a microscopic scale, while allowing the important base metal contacts to keep their ions and thereby remain undamaged by corrosion. 

Condition C - Non-Bridging Particles in Suspension and Encapsulation:  Since obviously most of the paste will be displaced, actually only a relatively small fraction of the zillions of tiny zinc particles will bridge the two base contacts.  In fact, most will just be in suspension in the paste and will not be in physical contact with either electrical contact.  These particles in the rest of the blob of grease which surrounds the connection donít carry any current (see above), or give up any a matter of fact, they donít do much at all besides take up space, and can be considered to just sort-of be along for the ride (kind-of like Steve G. in high school).  

So the secondary benefit is realized from the Encapsulation as the soft paste is displaced to the next easiest place to be...right next to and surrounding the joint.  This encases the joint in a protective coating which excludes moisture laden air in Oregon, or salty ocean air in Miami, or sulfuric acid droplets around the battery just about anywhere, from getting to the connection to do their dirty work and compromise it.  The cycle of new moisture getting to the contact surface promoting new corrosion is broken. A Gas-Tight-Joint has been made.  As noted before, with the creamy low viscosity of Idealís NOALOX product, the encapsulation benefit will be compromised as soon as the material runs away...and it will (from what my experience and semi-scientific practical tests have shown.  See:  Sw-Em ACZP Droop Test    ) would you like it if your toothpaste ran off the brush?  ...I personally would look for a new brand of toothpaste! 

Link to Additional Information:  Since I have used the 1/4" push-on terminal as an example here, the reader might be interested in this: The Lowly .250" Push-On Terminal


Reference Information: (my highlights!, my comment!):

From Burndy's site (,127616):

P8A Penetrox Anti-Oxidant:  Petroleum Base with suspended zinc particles

PENETROX oxide-inhibiting compounds produce low initial contact resistance, seal out air and moisture, prevent oxidation or corrosion, exhibit superior weathering characteristics, are usable over wide temperature ranges, and provide a high conductivity "gas-tight" joint. All PENETROX compounds contain homogeneously suspended particles. The particles assist in penetrating thin oxide films, act as electrical "bridges" between conductor strands, aid in gripping conductor, improve electrical conductivity and enhance integrity of the connection. The specially formulated PENETROX compounds are for use with compression and bolted connectors providing an improved service life for both copper and aluminum connections. Additionally, the non toxic compounds are an excellent lubricant for threaded applications reducing galling and seizing.


From Ideal's site ( ):

Noaloxģ Anti-Oxidant Compound


From Gardener-Bender's site:




A Good Reference:  Radio amateur K1TTT 's page for more good info on these products including pricing/sources:  ]  

Link to related thread (warm wires!):


This article is Copyright © 2008-2015.  Ronald Kwas.  The terms Volvo, Burndy, Penetrox, Ideal, Noalox, are used for reference only.  I have no affiliation with any of these companies other than to try to keep their products working for me, help other enthusiasts do the same, and also present my highly opinionated results of the use of their products here.  The information presented comes from my own experience and carefully considered opinion, and can be used (or not!), or ridiculed and laughed at, at the readers discretion.  As with any recipe, your results may vary, and you are, and will always be, in charge of your own knuckles! 

You are welcome to use the information here in good health, and for your own non-commercial purposes, but if you reprint or otherwise republish this article, you must give credit to the author or link back to the SwEm site as the source.  If you donít, youíre just a lazy, scum sucking plagiarist, and the Boston Globe wants you!  As always, if you can supply corrections, or additional objective information or experience, I will always consider it, and consider working it into the next revision of this article...along with likely the odd metaphor and probably wise-a** comment. 


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