Questions about Dielectric Greases

[JmanC]

Just a few questions as I have no experience with this stuff. Done a search online but cab't find anything.
How long do they provide corrosion resistance between mating surfaces? Like between a lug & busbar.

When the corrosion protection wears off do I simply apply another coat or is there some hard buildup/layer left that needs to be scrubbed or cleaned off?

cheers

[thinwater]

Originally Posted by JmanC

Just a few questions as I have no experience with this stuff. Done a search online but cab't find anything.
How long do they provide corrosion resistance between mating surfaces? Like between a lug & busbar.

When the corrosion protection wears off do I simply apply another coat or is there some hard buildup/layer left that needs to be scrubbed or cleaned off?

cheers

Dielectric greases generally contain very few additives, or they would conduct electricity. They inhibit corrosion by excluding oxygen and water. There are inhibiting greases, such as Al-noox and No-Ox-id that contain corrosion inhibitors.


In truth, you will do as well with a good waterproof grease, such as Green Grease or even Lanocote.


No, there generally is nothing to scrub-off, other than the typical grease residue.


It's not that complicated to get a lasting joint. Clean. Tight. Grease. (The clamping force push the grease out of the way,)

[Wotname]

What thinwater said plus.

Most dielectric grease are low pressure greases which means they will squeeze out easily under pressure.

I apply the dielectric grease (I use Dow Corning #4) to all the cleaned surfaces (lug/busbar/etc), assemble and tighten up and forget for a year or two. Then repeat

[sailormed]

Dow Corning #4 is what I use. Apply, assemble, tighten connection, forget. Grease is squezed out at contact area.

[a64pilot]

Silicone grease like the DC4 mentioned is just silicone grease, it’s just grease nothing special.
However silicone grease is clear and pure, won’t break down rubber and plastics like most petroleum greases will and will never dry out and turn hard and waxy, it will of course attract dirt and dust.

[smac999]

Originally Posted by JmanC

Just a few questions as I have no experience with this stuff. Done a search online but cab't find anything.
How long do they provide corrosion resistance between mating surfaces? Like between a lug & busbar.

When the corrosion protection wears off do I simply apply another coat or is there some hard buildup/layer left that needs to be scrubbed or cleaned off?

cheers

You don’t want anything between a lug a busbar. Deieletric grease dies not conduct.

There are things you can put over top.

[wrwakefield]

A light spritz of CorrosionX keeps all of my exposed electrical connections corrosion free.

Unrelated- It also works well on all the bronze throughhull valves to keep them pristine.

Cheers! Bill

[a64pilot]

Silicone grease is non conductive, it’s also very thin and squeezes out so that it causes no problem.
Go to the auto parts store, get a pack of “light bulb” grease meant to smear on the base of auto light bulbs to prevent corrosion, it’s simply silicone grease and works fine on light bulbs, and they have very little pressure compared to a screw down bus bar.

I’m a big fan of corrosion-x myself. In fact I keep my outboard and Yanmar and generator liberally sprayed with it, wash each engine every other year or so and re-apply, and hav easel corrosion on all three.
Try it, you’ll like it

[MarkI]

Is anyone willing to describe a recommended grease and application method to protect Shore power sockets? Like:
Use, Grease x, applied with tiny brush to male contacts???

What about female contacts, they seem important also.

I saw lots of indirect comments on the shore socket discussion, but nothing explicit.

[a64pilot]

Originally Posted by MarkI

Is anyone willing to describe a recommended grease and application method to protect Shore power sockets? Like:
Use, Grease x, applied with tiny brush to male contacts???

What about female contacts, they seem important also.

I saw lots of indirect comments on the shore socket discussion, but nothing explicit.

I fill up the female end completely with DC4, that of course gets all over the male side too.
If it makes a mess it wipes up easy

[Jdeuel]

Along this line of thought, what would be the best thing to use on an Apple Lightning connector? I've had the 'gold' (obviously NOT gold) contacts corrode and fall apart after a few days around salt. I read an account a couple years ago about a R2AK boat who had all the backup devices they could possibly need for navigation, but were stymied by a lack of working cables.

[cpisz]

Regarding the lightening connector. You have a problem because if you use a non conductive grease then you will not have reliable connections, but if you use a conductive product then you will short the connections together. They are small and close together. There is no great solution here I think. Clean it regularly and keep it dry.

[Mike Banks]

Before they were invented we used Vaseline.

[Wotname]

Originally Posted by smac999

You don’t want anything between a lug a busbar. Deieletric grease dies not conduct.

There are things you can put over top.

My experience is that you get superior corrosion protection by putting it between the contact areas before assembly and tightening.

Decades ago I was doubtful for the reasons you mention but after trying it and seeing the obvious improvement I became a convert. Later on I learnt about he differences between low pressure, high pressure and extreme pressure greases and the reasons why it worked became clear.

As an aside, we used to have a lot of corrosion problems on electrical connections behind the instrument panel of some flying boats. After introducing some DC4 into the connectors, the problems disappeared ten fold. If a push on connector has enough pressure to displace the grease, a bolted down lug on the busbar certainly has.

[Wotname]

Originally Posted by thinwater

Dielectric greases generally contain very few additives, or they would conduct electricity. They inhibit corrosion by excluding oxygen and water. There are inhibiting greases, such as Al-noox and No-Ox-id that contain corrosion inhibitors.


In truth, you will do as well with a good waterproof grease, such as Green Grease or even Lanocote.


.........

I would urge some caution about using some greases, in my mind they really should be of low pressure style of grease. I don't have hard evidence to support this claim but it kinda makes sense to stick to the LP greases.