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View Full Version : Electrical Dielectric grease on relays a good idea?



Redsquall
05-03-2016, 09:51 PM
I have Permatex brand - should I be putting that on all the relays when I change them? Thanks guys Guys

skill
05-04-2016, 12:06 AM
No. I wouldn't. I've disconnected connectors to find old dried up mustard colored dielectric gunk inside fouling up the contacts. Keep the connections clean -metal to metal. Now, if you want to prevent moisture from getting into the the connection put the dielectric grease around the connections. I really don't think the fuse relay area need it though.

Bitsyncmaster
05-04-2016, 06:00 AM
I don't use it. I have seen oils from your fingers cause problems with digital signal connections. But the power company's use it with aluminum wire connections.

DMC-81
05-04-2016, 07:41 AM
Agreed. I use it on the exterior connections, but not inside the car.

hmcelraft
05-04-2016, 09:14 AM
I use dielectric grease sparingly on contacts in the electrical compartment above the battery and externally. I began using it in the compartment when I used the a venting lead-acid battery. I found that the venting gases, even with the vent in the battery chamber, corroded virtually every connection in the compartment. The grease helped in preventing loss of contact. I use Optima batteries now but, I still use the dielectric grease. It seemed to really help in keeping corrosion off the contacts.

PJ Grady Inc.
05-04-2016, 04:38 PM
Dielectric grease is an insulator not intended for the actual electric connection but rather to lubrication and seal the rubber around it such as spark plug boots or other protective boots. A better solution is a compound made to conduct current as it seals and lubs the connections such as Kopr Shield by Thomas Betts. It's available from McMaster Carr in a 1.5 Oz brush top bottle for under $10-. Used sparingly as too much can cause multi-prong contacts to short across the protective housing if globed on carelessly.
Rob

David T
05-05-2016, 11:14 AM
The theory behind the use of "Die electric grease" is that when used around electrical contacts it prevents air and moisture from getting to the actual metal contacts preventing oxidation. One of the problems with it's use is if you use on on contacts carrying high currents, they can get hot and cause the grease to vaporize. The grease itself is not conductive but if it vaporizes it can cause problems with the connections.
What is normally done to prevent oxidation is the metal of the contacts is plated. Once the plating is removed by cleaning the contacts will oxidize much quicker. What also happens is the springiness of the connectors is lost when the connector is overheated so it no longer grips the other contact tightly leading to a bad connection, more heat and less contact. No way to fix that without replacing it. If fuses are oxidized the best way to fix that is not by cleaning or grease but replacing it with a new one. The copper grease is OK but messy and should not be necessary. Die electric grease is for use on the secondary ignition connections. It's main purpose is to prevent arcing of high voltage connections. Anywhere else is not recommended.

PJ Grady Inc.
05-05-2016, 11:53 AM
The theory behind the use of "Die electric grease" is that when used around electrical contacts it prevents air and moisture from getting to the actual metal contacts preventing oxidation. One of the problems with it's use is if you use on on contacts carrying high currents, they can get hot and cause the grease to vaporize. The grease itself is not conductive but if it vaporizes it can cause problems with the connections.
What is normally done to prevent oxidation is the metal of the contacts is plated. Once the plating is removed by cleaning the contacts will oxidize much quicker. What also happens is the springiness of the connectors is lost when the connector is overheated so it no longer grips the other contact tightly leading to a bad connection, more heat and less contact. No way to fix that without replacing it. If fuses are oxidized the best way to fix that is not by cleaning or grease but replacing it with a new one. The copper grease is OK but messy and should not be necessary. Die electric grease is for use on the secondary ignition connections. It's main purpose is to prevent arcing of high voltage connections. Anywhere else is not recommended.

"The copper grease is OK but messy and should not be necessary." Really David!!!! I find it indispensable for revitalizing corroded electric bulkhead terminals, marker light and T/S sockets, among other things. I use the stuff almost daily.
Rob