Dielectric greases FAQ ?

Questions for you dielectric experts!

What kinds of dielectric grease are there? I am thinking I have seen and used three kinds (maybe they have different names) over the years.

Also why is callled dielectric grease (is that even the right name for it?).

(1) I have seen electrically conductive grease for things like fuse disconnect slide switch surfaces (good for large high amperage flat copper to copper contacts) in AC wiring.

(2) Heat conductive (but not electrically conductive) for computer CPU heat sinks/fans.

(3) and I think a non electrically conductive, oxidation inhibitor grease, paste..... to displace water, and keep low voltage electronic contacts from oxidizing.

I have read a lot about de-oxit (?), and generic names here in this forum for use with various connectors on the Jeeps.

I would like to know (and sure others would too) which ones (brand name and it class, 1,2 or 3, or type) you used and liked and where you used them successfully, as well as where not to use them perhaps!

Also, I am getting ready to buy some in bulk (type 3, I think), so I would like to know a good souce for a large quantity, not just 1/4 oz samples for $10, like I have seen at the stores lately, but more like 1 to 6 oz sizes for a reasonable price.

Thanks!

"Dielectric grease" is more a generic name than anything else, I think.

As far as using any sort of compound on any sort of electrical or electronic (or related) connection...

1) Dielectric grease is something I use on spark plugs to make the rubber boots easier to remove. I typically use Permatex. This seems to be what it is designed for - I wouldn't use it as a corrosion inhibitor, for instance.

2) Corrosion Inhibitor (Ox-Gard and the like) is something I use on nearly every wiring connection that isn't otherwise sealed (like Delphi Weatherpack or Deustch connectors,) or that I am building myself when I want to ensure high reliability. For instance, I use Ox-Gard to "pack" the connectors on all my mains cables that I make. This stuff is actually designed to help prevent corrosion on "live" connections - therefore the coating that it forms is highly conductive, and doesn't interfere with power or signal transfer.

3) Thermally-Conductive adhesive (temporary or permanent.) This is used to affix a heat sink to a heat source, and can be sold as a one-part compound (like heat sink grease) or a two-part compound (like thermally conductive epoxy.) Note that "thermally-conductive" doesn't always mean "electrically-conductive" - if you're using a semiconductor that grounds through the heatsink tab, make sure the adhesive/compound you use can conduct both heat and electricity efficiently (it isn't always a two-way street.)

I generally prefer to stick to name brands for stuff like this - like Permatex, Gardner/Bender, and the like. If someone has been around that bloody long, they should be doing something right! That, and I've developed a huge distrust of "Made in China" over the last dozen years or so. There are good manufacturing facilities on the Pacific Rim, but I haven't run across any in China...

By definition, dielectric means nonconducting.

The main purpose of dielectric grease is to protect electrical connections from salt, dirt, condensation, and corrosion, all of which can hinder good conductivity between metal contacts. Secondary purposes include heat dissipation and lubrication, though I wouldn't rely on it for either of those except when using it on spark plug boots.

A common misconception is that dielectric grease is conductive. In that sense, some may wonder why they should use it on electrical connections. It's usually not a problem because the grease is displaced when the connectors make contact. If the grease was conductive, it would allow the electrical signal(s) a path to ground or short to an adjacent signal, depending on the type of connection. That wouldn't be a good thing.

5-90,

Your reply jogged my memory, dielectric is short for hi-dielectric strength, meaning it does not break down readily when exposed to high voltages, i.e. its good for high voltage wires, in our case spark plug wires!!!

I only have one problem with your comments below. I do not think the Corrosion Inhibitors like Ox-Gard are actually electrically conductive. Perhaps some are and some are not?

My problem is this if they were elecritically conductive they would short out multiwire and bulkhead connectors!

The electrically conductive corrosion inhibitors (Ox-Gard?) would be great for battery cable connections, cable grounds and the like, but not for multiwire connectors.

So is Ox-Gard really electrically conductive, or does it just keep the connections oxide free and moisture free so that they conduct where they make contact?

Is there a good place online to get reasonable sized containers of Ox-Gard with out breaking the bank?

I am currently looking for an Ox-Gard like product that is not electrically conductive, one that is designed for multi-wire connectors, that stops moisture, acid vapors, and oxide formation and that does not dry out, evaporate, gum up.

Ecomike said:

Questions for you dielectric experts!

I have read a lot about de-oxit (?), and generic names here in this forum for use with various connectors on the Jeeps.

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I have had a lot of experience with de-oxit back in my copier tech days. It is a contact cleaner for pin/jack connections, especially the really tiny ones. I do use it on my vehicles. I did a little writeup on this recently. You have to remember that just cleaning a plug/jack is not enough if the contact is not tight. Corrosion can still build up between the mating surfaces, and corrosion equals resistance. The Jeep connectors are big enough that you can get in there with a tiny needlenose pliers and squeeze down on the female ends. This will ensure more contact surface when you replug the connection. I usually squeeze the contacts, apply a shot of de-oxit, then plug/unplug once to work the cleaner in, then connect for good.

Ecomike said:

5-90,

Your reply jogged my memory, dielectric is short for hi-dielectric strength, meaning it does not break down readily when exposed to high voltages, i.e. its good for high voltage wires, in our case spark plug wires!!!

I only have one problem with your comments below. I do not think the Corrosion Inhibitors like Ox-Gard are actually electrically conductive. Perhaps some are and some are not?

My problem is this if they were elecritically conductive they would short out multiwire and bulkhead connectors!

The electrically conductive corrosion inhibitors (Ox-Gard?) would be great for battery cable connections, cable grounds and the like, but not for multiwire connectors.

So is Ox-Gard really electrically conductive, or does it just keep the connections oxide free and moisture free so that they conduct where they make contact?

Is there a good place online to get reasonable sized containers of Ox-Gard with out breaking the bank?

I am currently looking for an Ox-Gard like product that is not electrically conductive, one that is designed for multi-wire connectors, that stops moisture, acid vapors, and oxide formation and that does not dry out, evaporate, gum up.

Click to expand...

It's possible that I've got a wire crossed there - perhaps it's just formulated to (technical talk here...) "squidge" out thoroughly between contacts, so it can protect them without inhibiting them? Sounds like I'll have to do some checking on my own one of these days - I've only ever really used it on "single contacts," and I'm not overly generous with it when I think it could spill over into another circuit (physically speaking.)

Meanwhile, I need to find a place to get larger cannisters of Ox-Gard myself - I've just been busy with other things for the moment...

Here is the Technical data sheet for Permatex dielectric grease.

Here is more info about Ox-gard (the GB website doesn't even list Ox-gard)

One company, Thomas & Betts make a product called copper coat and alumi coat, they are a grease based product with either copper or aluminum particles. They are used extensively in the home market and business markets in breaker boxes, where the main line comes in and goes into the lugs on the power panels, the ones you normally tighten down with a big allen wrench. You will find that higher end electricians use it, when I had my house done I had to give the electrician my can before he put the cables in from the meter to the box.
There are some other products that are made to be applied after you have made a connection, again by T&B and either copper or aluminum based wiring. The spray is actually rated for marine use on two of the products and is used to say seal a ground bolt and nut to prevent corrosion, stuff needs a solvent to remove it though if you ever want to unbolt it again, spray the solvent and get the nut or bolt off quick before it dries again

langer1 said:

Dielectric greases can be substituted for KY jelly but not the other way around.

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Why not....

Upon further research dielectric gets its name from diathermic electric blankets. It seems old style electric blankets used a particular heating element that broke down when combined with termal transfer paste. These were the first generation blankets back many decades ago. Anyway, they found that this "goo" had useful properties and became what we now know as dielectric grease. :dunce:

RichP said:

Why not....

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Why would anyone even want to substitute it in the first place?

Tom R. said:

Upon further research dielectric gets its name from diathermic electric blankets. It seems old style electric blankets used a particular heating element that broke down when combined with termal transfer paste. These were the first generation blankets back many decades ago. Anyway, they found that this "goo" had useful properties and became what we now know as dielectric grease. :dunce:


Why would anyone even want to substitute it in the first place?

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Ever heard the term 'never look a gift horse in the mouth', errrr, never mind

langer1 said:

Dielectric greases can be substituted for KY jelly but not the other way around.

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How do you learn this? :shhh:

AlabamaDan said:

How do you learn this? :shhh:

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The same way you learn cornstarch can be used to replace KY, and make it look like you are rubbing cocaine all over...