I posted this question on the electrical Board but thought that Dielectric Grease could be considered an all around usefull compound in the garage. Besides, you Garage folks are a strange lot and come up with some cool replies.

I need someone to confirm or deny my assumptions regarding the use and qualities of Dielectric Grease (DG).

I understand that DG is used as a lubricant for the Rotor within a distributor. It has been suggested in some places that DG can be used for plug together type electrical connections.

My assumption is that DG is both a lubricant and an electrically conductive element unto its self. That is the grease will act to improve the electrical connection due to its conductive nature. If it did not have this conductive quality a thin film of it on a connection would have an electrically isolating quality.

What are the conductive vrs isolating qualities of Dielectric Grease?
Are there other cool uses you all have heard for DG
I am going to do an Ohm test on a sample

Rob

 

There are several threads here that discuss wiring practices. Do a search on "dielectric".

Silicone Dielectric Grease (DG) is an insulator and is non-conductive. It keeps moisture out of connections when used on both spark plugs and regular low voltage connections. When you use DG in a connection and slide or bolt the connectors together you make a metal to metal contact that carries the current. The DG seals out air and moisture at these contact points which prevents corrosion. I use DG even on wires b4 I crimp them into connectors. I have not had a connector/connection failure in over 20 years using this method.

 

It's a good lube for brake caliper slides.

 

Re: other uses for dielectric grease: I use it as a floatant on dry flies when I fly fish.

 

i've heard that petroleum jelly (vaseline) does the same thing as this magic electrical grease, but way cheaper. is this true?

 

In my experience it works OK for a corrosion inhibitor but it doesn't work as well as silicone. It also melts off easier with just a little heat so it does not stay in place. If exposed to enough heat it will break down into carbon which is a conductor. You can't use it on high voltage connections because it absorbs water and will loose it's dielectric properties, if it had any in the first place. The heat will break it down on plugs and short them out.

 

Noalox By Ideal industries is the compound used by electrications This is only good for aluminum conductors The purpose of this product is to break through the aluminum oxide on the wire when used in a pressure connection
Ingredients are,
<80 Polybutene
20 Zinc Dust
<5 Silicon Dioxide
The zink dust is conductive but that is not what the compound in intended for. It is intended to prevent oxidation of aluminum conductors and termanials (the grease part of it) and break the aluminum oxide on the wire (the zink dust part of it)
If used on copper wire it does nothing other than plain old grease would do.

If you are going to bolt a copper ended battery cable to an aluminum engine block, put it on the block. For Copper to cast or steel just use plain old grease.

 

What about the DG that you're supposed to put on the back of a control module? It was explained to me that it is for heat reduction. Its kind of a thick white grease, whereas the kind you get with plug wires is lighter. Do they have different properties?

 

The "dielectric grease" you are referencing for putting on the back of an ignition module is not dielectric grease. Someone may call it that but they are incorrect. The white paste that is put on ignition modules and electric/electronic heatsinks is "Thermal Heatsink Compound". It contains silicon based oils but it is definitely NOT dielectric grease. DO NOT use them interchangeably, they are not the same stuff.

Use Silicon Dielectric grease (usually clear) for plug wires, electrical connections, and lubrication.

Use Heatsink Compound (usually white) for electronic component heatsinks and ignition modules (they are electronic components). Some high performance heatsink compounds are electrically conductive. The purpose of heatsink compound is to fill the microscopic voids between two surfaces (usually metal) and facilitate the transfer of thermal energy.

There are a few products that are described as "dual purpose" but they have a rather limited functionality for both uses. In other words they may "work" but not as well as the "real" stuff.

Use the proper product for the application.