Vaseline on battery posts

[srah1953]

In the book "Electrics Afloat", the author suggests using vaseline on thru deck glands to make them them waterproof but warns against getting any vaseline on the actual connections as it would act as an electrical insulator. I have read in numerous places to protect battery terminals with vaseline. Would this not diminish the electrical connectivity between post and cable?

 

[pampas]

The method that I was taught as an appentice was to keep and make a clean pillar metal to metal connection then smarm vaseline on.

 

[SAWDOC]

In the book "Electrics Afloat", the author suggests using vaseline on thru deck glands to make them them waterproof but warns against getting any vaseline on the actual connections as it would act as an electrical insulator. I have read in numerous places to protect battery terminals with vaseline. Would this not diminish the electrical connectivity between post and cable?

I don't think there is any contradiction in the above.

 

[cimo]

yes - make the connection first and then apply the external moisture barrier.

 

[VicS]

And a good way of cleaning battery posts is with a "Scotchbrite" pot scourer. Cleans them nicely but does not remove any metal.

 

[sarabande]

petroleum jelly is hydrophobic (water-repelling) and insoluble in water, so it acts as a barrier to moisture. It increases its electrical conductivity when you bombard it with ionising radiation - apparently.

A (perhaps) little known factoid for you. Do not use Vaseline or PJ while wearing latex gloves, as it dissolves the latex pretty quickly. This applies to other personal latex products too.



(discovered this while wearing latex gloves and performing obstetrics on sheep.)


EDIT

VicS - advice pls.

Kay and Laby give a figure of 2.1/1.9 against petroleum jelly for conductivity. I'm not familiar with those figs, so can you explain pls ? Is petroleum jelly electrically conductive ? If so, how conductive ? TIA.

 

[Beadle]

The "professional" way to do it - on connectors carrying hundreds of amps - was to smear the post with Vaseline and then give it a good rubbing with a wire brush.

The theory being that tiny particles of copper or aluminium are caught up in the Vaseline and when you tighten the connector these ensure that there is a very low resistant path while the Vaseline makes the joint air and water proof.

 

[VicS]

VicS - advice pls.

The two figures are the **relative permittivity at the two tempertures (20C and 60C) quoted in the temperature column

They are not the electrical resistivity (or conductivity). Resistivity is table 2.6.3 in the online edition but there is no entry for petroleum jelly.


**relative permittivity is another name for dielectric constant!

 

[JohnTH]

More years ago than I care to remember, I too was trained to clean terminals before connection and to use petroleum jelly (afterwards) to protect the joint. If, whatever it was, then had to live in a particularly harsh environment, it was to be wrapped in “denso” tape.

Decades, yes, decades later, I have pulled equipment out of service to find perfectly preserved, functioning joints.

Wire wool had been the tool of choice for cleaning until that green (why green) abrasive material came along.

Ah, happy days……..we all had to sing “all things bright and beautiful” before cleaning up to make a joint or slapping the flux on and soldering.

I had never ever imagined being able to qualify to recount stories like this, just goes with seniority I guess !

Oh, silicone grease (looks like Vaseline) is not (do I need to repeat that?) the same.

73s de

Johnth

 

[Trundlebug]

I know it's been common advice given by many for years to smear all things electrical in vaseline, but I for one have never done it, for a couple of reasons:-

1. Vaseline may be water repellant, but it's attractive to dust and dirt, which accumulate over time and may often be the cause of subsequent shorts, or at least some leakage or tracking.
2. Every time you go anywhere near the battery terminals you'll end up getting covered, somewhere, with the stuff on your clothes. Whether you notice or not at the time, either way it's a PITA.

If, because of (1) above you end up having to clean off the terminals and reapply regularly, I came to the conclusion it's not saving any great amount of time, or effort compared to just keeping the terminals completely clean and dry - which is what I do, and have done on cars and boats for 20+ years now. Cleaner, better, easier. With minimum effort - and I haven't (touch wood) had any problems AT ALL with growths of green corrosion etc.
So I begin to think this vaseline stuff is a bit of an old wives' tale.

Personal opinion of course!

 

[Alfie168]

A (perhaps) little known factoid for you. Do not use Vaseline or PJ while wearing latex gloves, as it dissolves the latex pretty quickly. .

The clue is in the name Petroleum Jelly..its the petroleum bit that does for latex PDQ.

I use vaseline and the idea of wrapping the battery connector/post in denso tape makes sense.

Tim

 

[boatmike]

In the book "Electrics Afloat", the author suggests using vaseline on thru deck glands to make them them waterproof but warns against getting any vaseline on the actual connections as it would act as an electrical insulator. I have read in numerous places to protect battery terminals with vaseline. Would this not diminish the electrical connectivity between post and cable?

Sorry, but on reading this thread my first reaction was .......what???? What has been said here contradicts everything I was ever taught. Vaseline is petroleum jelly and is in fact electrically conductive. That's why you use it in preference to other forms of grease.
It's purpose is to inhibit corrosion and fill any air gap that would promote ozone build up in the joint. You should always coat the MATING PARTS of the joint with it not make the joint then cover it with the stuff afterwards. For verification I looked it up in my handbook of electrical theory and have pasted the appropriate extract here.


4.2.1. Petrolatum.-Petrolatum (trade
name Vaseline) is perhaps the first- used
joint compound. It aids in preventing ox-
idation and aids in excluding moisture

ing copper and plated copper connec
tions.

4.2.2. NO-OX-ID.- This grade "A special"
is a petroleum base compound with
higher melting point, higher oxidation re-
sistance, and better weathering charac
teristics than petrolatum. It is widely used

4. Preparation of Conductors bus connections.
4.1. CLEANING CONDUCTORS.- Surface 4.2.3. Alcoa No. 2 EJC.-Alcoa No. 2
contamination, specially surface oxide, EJC, electrical joint compound, is a pat-
must be expected on all conductors. These ented compound of an active chemical in
surface oxide films are insulators and must a grease-type sealer. It penetrates oxide
be broken down to achieve the metal-to- film by chemical action and is recom
metal contact required for efficient electrical mended for aluminum- to-aluminum con-
connections. Aluminum oxide, in particular, nections, particularly bolted aluminum
forms very rapidly; therefore, aluminum cable connectors on weathered aluminum
conductors must be thoroughly cleaned by cable. Alcoa No. 2 EJC is corrosive to
use of an emery cloth or a rag immediately steel and tinned copper fitting and it
prior to making the connection. In addition should not be used on flat-pad bus con-
to cleaning, the surface should be covered nections in substations.
with a good joint compound to exclude
moisture, thus preventing the oxide from 4.2.4. Alcoa filler compound.-Alcoa
reforming. Somewhat better results may be filler compound has a fine grit of alumina
obtained by abrading the aluminum (not suspended in it and is used for transmis
copper) surface through the joint sion line compression dead- end, splice,
compound. When joining or terminating and terminal joints on aluminum or ACSR
insulated conductors, the insulation should conductors.
be removed from the contact area by
"pencilling" rather than by "ringing" with a 4.2.5. Pentox "A" (Burndy) and Alnox
sharp tool. This will limit conductor damage (Alcoa).- These are electrical joint com
and facilitate application of insulating tape pounds used for aluminum-to-aluminum
and/or compound. and aluminum-to-copper connections,
particularly of the bolted flat-pad type.
4.2. JOINT COMPOUNDS.-Joint com- Pentox "A" consists of a suspension of
pounds are used when making electrical zinc granules in a paste carrier which is
connections to (1) prevent formation of ox- workable over a wide temperature. The
ides on the cleaned metal surfaces and (2)

In cutting and pasting the paragraph sequence has been lost. Read the paragraph numbers in order to make sense.

 

[lw395]

The clue is in the name Petroleum Jelly..its the petroleum bit that does for latex PDQ.

I use vaseline and the idea of wrapping the battery connector/post in denso tape makes sense.

Tim

What do you mean by denso tape?

I find an effective way of lessening corrosion on battery terminals is to do them up clean and dry, then spray and wipe over with a silicone/ptfe aerosol such as GT85. It stops dirt sticking and repels water from the little gaps.
Vaseline is very good for multiway connectors, the ones on Moto Guzzi's used to corrode and fail in no time unless filled with the stuff.

 

[VicS]

What do you mean by denso tape?

Google. Youll soon find it. One of the messiest, gooiest, sticky things on the planet. Fortunately it does not also smell foul.

 

[boatmike]

Sorry I am **** at this! Every time I try cutting and pasting it comes out jumbled. Go to
http://www.usbr.gov/power/data/fist/fist3_3/vol3-3.pdf
and Para 4 (lets hope that works!)

 

[VicS]

Vaseline is petroleum jelly and is in fact electrically conductive

Nobody has told my multimeter and the jar of Vaseline we have here then.
Nothing it the description of the stuff would lead me to predict that it would be either.

The section of the above link only says about Vaseline:

4.2.1. Petrolatum.-Petrolatum (trade
name Vaseline) is perhaps the first- used
joint compound. It aids in preventing ox-
idation and aids in excluding moisture
from connections. It is still useful in mak-
ing copper and plated copper connec-
tions.​

No mention of being electrically conductive

 

[lw395]

Nobody has told my multimeter and the jar of Vaseline we have here then.
Nothing it the description of the stuff would lead me to predict that it would be either.

Perhaps he uses vaseline handcream instead of petroleum jelly. I vote we go to Boots with a multimeter and check the whole range of products?


I think in reality it does not matter, the terminals are done up tight enough to achieve metal to metal contact. The grease/whatever then fills the crevices, reducing corrosion.
It does tend to attract dust, which then holds water if it gets damp, so it can be counterproductive on poorly sited motorbike batteries, like mine where you have to take the fairing off to see the battery, but it sees a lot of road dust and spray.

 

[boatmike]

Nobody has told my multimeter and the jar of Vaseline we have here then.
Nothing it the description of the stuff would lead me to predict that it would be either.

The section of the above link only says about Vaseline:

4.2.1. Petrolatum.-Petrolatum (trade
name Vaseline) is perhaps the first- used
joint compound. It aids in preventing ox-
idation and aids in excluding moisture
from connections. It is still useful in mak-
ing copper and plated copper connec-
tions.​

No mention of being electrically conductive

Read the rest!!! It clearly describes a jointing compound. Jointing compounds go er....in the joint???? It also clearly states the best connections are made when the material is abraded THROUGH the compound which negates the further formation of oxides. It does NOT say clean it off afterwards or only apply to the outside of the joint. I have been making battery connections like this for the last 50 years. I have ALWAYS applied it to the post and connector mating surfaces. It has always worked perfectly.

 

[Trundlebug]

I once tried using copper grease on battery terminal posts, my thinking being that it would conduct better than vaseline (it didn't) and would still prevent corrosion.

It was just as messy though, and when it didn't even conduct properly (much to my surprise) I stuck with my tried and tested "keep it clean and dry" method.

 

[VicS]

Perhaps he uses vaseline handcream instead

Yep, tested some hand creams and other skin care products.
All conduct
All also highly perfumed ... so if you ever come across some high voltage switchgear that smells like a tart's boudoir you'll know who has been working on it