davekp78

What's the consensus on using dielectric grease on connectors? How to apply? How much to apply?

71scgc

Use it always. Too much is better than not enough,
Be aware that there are different types of dielectric grease.

Carter

Railroadman

An old-time locomotive mechanic I knew used to smear some Vaseline on the power contactor tips. Said it worked just fine. I followed that advice and put some on each time we did the maintenance. Nvere had a problem and the tips seemed to last quite well.

What's the thoughts on using that for Corvette applications? Sure why not, or No Way, Jose??

71scgc

It's better than nothing, especially in areas more exposed to weather, such as light bulb sockets.
I used to use Noalox on my battery terminals. It's used on electrical applications with aluminum cable, and should always be used on copper to aluminum connections.

My grandfather was a railroad electrician. Made the steam to diesel transition. He was a neat guy. He could fix ANYTHING.

Carter

GTOguy

Absolutely. Prevents oxidation of connector terminals, maintaining clean contacts. And because of this, prevents high resistance due to corrosion, and broken/frozen connectors. Out where I am, not as critical as it's dry and arid. I always use it on spark plug leads, though, and have on thousands of cars over the past few decades. Sure helps when it's time to pull the ignition wires off the plugs when you want to re-use the wires!

csherman

Dielectric grease is electrically insulating and does not break down when high voltage is applied. It is often applied to electrical connectors, particularly those containing rubber gaskets, as a means of lubricating and sealing rubber portions of the connector without arcing.

A common use of dielectric grease is in high-voltage connections associated with gasoline engine spark plugs. The grease is applied to the rubber boot of the plug wire. This helps the rubber boot slide onto the ceramic insulator of the plug. The grease also acts to seal the rubber boot, while at the same time preventing the rubber from becoming stuck to the ceramic. Generally, spark plugs are located in areas of high temperature and the grease is formulated to withstand the temperature range expected. It can be applied to the actual contact as well, because the contact pressure is sufficient to penetrate the grease film. Doing so on such high pressure contact surfaces between different metals has the advantage of sealing the contact area against electrolytes that might cause rapid deterioration from galvanic corrosion.

Another common use of dielectric grease is on the rubber mating surfaces or gaskets of multi-pin electrical connectors used in automotive and marine engines. The grease again acts as a lubricant and a sealant on the nonconductive mating surfaces of the connector. It is not recommended to be applied to the actual electrical conductive contacts of the connector because it could interfere with the electrical signals passing through the connector in cases where the contact pressure is very low. Products designed as electronic connector lubricants, on the other hand, should be applied to such connector contacts and can dramatically extend their useful life. Polyphenyl Ether, rather than silicone grease, is the active ingredient in some such connector lubricants.

Silicone grease should not be applied to (or next to) any switch contact that might experience arcing, as silicone can convert to silicon-carbide under arcing conditions, and accumulation of the silicon-carbide can cause the contacts to prematurely fail. (British Telecom had this problem in the 1970s when silicone Symel® sleeving was used in telephone exchanges. Vapor from the sleeving migrated to relay contacts and the resultant silicon-carbide caused intermittent connection.)

R66

I use NO-OX for electrical connections. Apply it to the contacts sparingly with a small painter's brush. It improves the electrical connection and protects from oxidation. Don't glob it on as it does conduct electricity and could create a short between two terminals on a connector.

I won't make up a connection without it.

mikem350

For my multipin plastic connectors, I spray WD40 both sides on the pins. Doing this on all my jobs for 30 years. Its good in electronics like volume controls and PC board connectors.

SWCDuke

As previously stated, dielectric grease is an insulator, so it should not be used on low voltage connectors. Use it sparingly on high voltage ignition system boots.

Use WD-40 on low voltage connectors. It repels moisture and will prevent corrosion, but not make a gooey mess that attracts dirt and add resistance to the circuit.

Duke

EMD645F3B

Interesting. I'm also a locomotive mechanic and we use Vaseline on low voltage connections like battery connections and to lube the battery knife switch. Don't know why he would use it on high voltage contact tips. Those tips carry up to 1500v and 4000 amps. I looked in the EMD SD40-2 service manual I keep here at the house and it states HV contact tips should be kept clean and dry. The 1940s drill press I have uses a multi position rotary switch to access different windings in the motor for speed control. The instruction manual says to use Vaseline on those contacts as well.