Vaseline on battery posts

[lw395]

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.

Yes it works, but you were wrong to say it is (electrically) conductive. (It is reasonably thermally conductive.)
Absolutely, provably wronger than Tony Blair.

Doing the right thing for the wrong reasons.

What is your source book by the way? It looks kind of dated, but the bit about joining copper to alu conductors is interesting.

 

[VicS]

Read the rest!!! It clearly describes a jointing compound. Jointing compounds go er....in the joint?

Personally not contesting that.

I was contesting the statement that Vaseline is electrically conductive. It isn't.

 

[JohnTH]

Oh boy, this looks like it is going to run and run.

Denso tape is a product manufactured by Denso. The description by Vics (above) is absolutely spot on although I would like to know what a tart's boudoir smells like so that I can suggest to Denso to add this smell to their excellent tape !

My belief is that it is some sort of lanolin product.

73s de
Johnth

 

[boatmike]

Personally not contesting that.

I was contesting the statement that Vaseline is electrically conductive. It isn't.

Vic, I have always assumed that it was. You may however be correct and the stuff isn't truly conductive (although hydrocarbon based). However, my main point was in it's usage. The contention that it should be applied over the connection after it has been made is wrong. In fact as others have said this just attracts dirt. I think the answer is possibly given here http://www.satcure.co.uk/tech/silicone2.htm where the manufacturers of silicone grease are promoting it for the same purpose. It may be that its rating as a lubricant is in fact very low and it breaks down easily under pressure where perhaps a lube grease would not. The description given here is however totally correct in that using either in the joint excludes oxygen and therefore prevents corrosion IN THE JOINT which in time can insulate it. In my experience this happens mostly on the negative terminal (for reasons I can't explain) and can give rise to a phenomenon known in the motor trade as "Ozone block". This may not be correct terminology but what happens is that a connection will pass a low current until the starter motor is engaged and then everything (lights, instruments etc) all go out. Wait 10 minutes and try again and everything works until the starter is hit again. The problem is usually either the "earth" connector to the chassis or the negative battery terminal which when removed is covered in fine grey powder. The "ozone" theory is that when a high current is passed the arcing in the gap causes an ionised gas to form which insulates the connector until it disperses. I can't stand by the theory but it certainly happens in practice over time with a dry joint. Never with one jointed over Vaseline.
Hope this helps to explain our disagreement as I have usually respected your posts as authoritative. My point is about what to do. I may be wrong about why!

 

[cimo]

Vasline definetily not electrically conductive.

Hello Mike - your "ozone block" is what we refer to as "arcing depoists" here in my world. Although, from my own experience, more typically observed on switched contacts. With battery terminals, the vaseline acts as a diaelectric, discouraging any arcing that may otherwise occur across relatively large air gaps. If this were a re-curring issue, I'd be tempted to address the problem head on and make changes to ensure a better surface area contact between clamp & post.

So putting vasline "in" the joint is perfectly legit. The metal parts push thru the film to make the contact. (I have seen conductive jointing compounds that have minute metalic bits to assist conduction but I can't ever see myself using them).

Getting back to the OP - I wouldn't recommend vaseline "in" the contacts of thru deck fitting. I'm thinking about dirt and contact wear that could eventually result in poor mating. I don't apply it inside my battery terminals either (I put a light film over the made connection to stop oxidation). Should you get alot of buildup between the clamp & the post - I would recommend increasing the surface contact area by metalic means -I recall my father using strips of lead to beef out ill fitting battery clamps on his numerous tractors - he seemed perfectly happy!

rgds
c

 

[Stu Jackson]

Unless your batteries are in a completely inaccessible place (in which case you should consider moving them or getting maintenance free batteries - an oxymoron if ever there was one!), it's not really that hard to check the posts from time to time. In the almost 13 years we've had our (this) boat, and having gone through three different sets of banks, we have never had corrosion problems on the posts. The banks are both in the main cabin under the settee. If they're wet cells you should be checking them regularly, and if not, then once every few months should do it. Why put an insulating material on the battery posts? They do make battery post cleaning tools, just a round piece of metal with brushes inside - one handy twist and you're done - never had to use it.

 

[nedmin]

I,ve never used anything on battery terminals for too many years to remember. just keep them clean.The reason you get corrosion on battery terminals is because there is a leak where the terminal comes out the case .The hydrogen gas carries acid particles and causes the corrosion.If your batteries sound you should not get any corrosion.

 

[alexrunic]

what about silicone grease, that's what i had recommended by an auto electrician. it about 2 or 3 quid from RS

 

[cimo]

what about silicone grease, that's what i had recommended by an auto electrician. it about 2 or 3 quid from RS

Yep - silicone grease does the same job. i use it now and again - I last saw it up in the bow I think. (The first aid locker is usually nearer ).

 

[boatmike]

what about silicone grease, that's what i had recommended by an auto electrician. it about 2 or 3 quid from RS

Click on the link in my earlier post and you will see why.

 

[ghostlymoron]

What's the answer then ? I've read over the years that you should use vaseline on the terminals but I've never done it because I couldn't decide whether to put on the battery terminals (posts) and then connect the leads or assemble the joints and smear it on top. I must say I haven't had troublesome corrosion on boat, car or bike. If Vaseline is non-conductive, smearing on top seems the best method.

 

[Trundlebug]

Just leave them dry!

Why make work for yourself?

Make sure they're clean, tightened up properly, and covered to keep them dry and prevent dirt build up. (Ventilation holes are required though).

Check them over from time to time, you'll have to anyway if you check the battery levels, and that's it. No mess no fuss!