Quick question about dielectric grease

Thread Starter

Tifa

Joined Nov 5, 2009
14
Self confessed numpty here.

I wonder if there's anyone that can advise me on this stuff?
In the past I have used it on motorcycle electrical connectors.
A smidgeon on everything from lighting circuits to ecu multiplugs.
To date, everything has worked perfectly, with no problem.
Also, on strip down a few years later, the connectors appear to be good, with no signs of corrosion.
However speaking to a guy who repairs motorcycles for a living today, he advised me against it.
Confused now....have I been lucky up to now, or is it worth coating the connections?
Any advice would be great....thanks!
 

MaxHeadRoom

Joined Jul 18, 2013
23,924
Dielectric Grease is used to prevent water and vapour corrosion and as a moisture depletion product.
Primarily used in automotive use in spark plug shields.
Used in the right way I have found it an excellent product.
Max.
 

Hypatia's Protege

Joined Mar 1, 2015
3,226
Quick question about dielectric grease
FWIW the sole problem I've experienced in connection with said compound resulted from confusion of same with thermal transfer (AKA 'heat sink') compound -- $17k in 'burned' modules and four days sans electrical service because some fool (who shall remain nameless:oops::oops::oops:) couldn't be bothered verify consistency of intended application with product indicationo_O:oops:...

However speaking to a guy who repairs motorcycles for a living today, he advised me against it.
IMNSHO If he can't or won't tell you why - then he's only worth ignoring! --- That said, I don't advise application to 'open' moving parts (inasmuch as it would quickly become contaminated by airborne abrasives, etc...)

Very best regards
HP:)
 

user8192

Joined Nov 9, 2011
2
So-called "dielectric grease" is silicone grease or heavy silicone oil with an inorganic thickener added. Most rubber and plastics are not affected by it, so it is an excellent choice for excluding moisture from electrical connectors.

My dad used petroleum jelly ("Vaseline") on his car and trailer electrical connections for the same purpose since the 1950s to good effect. He'd put a dab of it in brake and turn signal lamp sockets, thus corrosion-proofing them and assuring the lights would work no matter how wet the weather. Silicone grease is a better choice now.

Some automotive manufacturers use white lithium grease in cable connectors to help keep moisture away from the contacts. If white lithium grease was previously used, silicone grease can safely be substituted. Fortunately, automotive electrical connectors have gotten much more reliable since the early 1980s, with elastomeric boots to help keep dust and moisture out.
 

DNA Robotics

Joined Jun 13, 2014
614
I have seen dielectric grease used on plug wires in distributor caps. Grease attracts dust / dirt and that attracts moisture, causing misfire when humid.
 

Hypatia's Protege

Joined Mar 1, 2015
3,226
I have seen dielectric grease used on plug wires in distributor caps. Grease attracts dust / dirt and that attracts moisture, causing misfire when humid.
What brand were you using?:confused: -- I've used the 'El-cheapo' Permatex brand (for many years) in dusty, humid, often corrosive (O3, NO2/HNO3) EHT applications with excellent results... Of course any 'gel'/'grease' will 'skin' with airborne particulate contaminants - hence the necessity of 'boots', covers, etc...

As an aside; Please be advised that it is the electric field (via ionization) that attracts contaminants -- the 'grease' is merely 'fly-paper' in that regard;)...

With constructive intent
HP:)
 
I use "chemical stuff" on everything.

Probably, the earliest use was when I was 10 and had an aquarium. It (Vaseline) was used on the florescent light bulbs. I always used it on any light bulbs, car or otherwise.

"conducto-lube and "Stabilant-22" are contact enhancers. The former is silver based.

Locktite 222 is a low strength thread locker. Used on eyeglass screws and just about anything. I used it to rebuild an ancient (1950's) X-ray power supply and a 30 kW 15 kV supply. The latter use was to prevent loosening, the high voltage divider made from a bunch of 625K power resistors.

Plumbing threads has it's special "stuff". Then there's O-ring grease.

And don't forget anti-sieze compound which is mostly a car thing.

I discovered this https://tom-pac.com/tp-2557-and-tp-2598-bearing-gel/ (TP-2557) when I had to select some grease for a vintage gas clothes dryer. The New Old Stock part was useless without new grease. I needed high temperature and water resistance.

Luber-plate is good for things like car hood latches.

A real tough one to find is "Christmas tree valve - a type of valve" gas valve lubercant. That's graphite based.

Locks get a graphite based lubercant.

Let's not forget Teflon tape for gas and water lines. The gas line "yellow" version is different.

One application, that still needs research is grease for a demolition hammer bit. It needs impact and sliding properties and should not be hydroscopic.

In some applications like vacuum systems and air conditioning O-rings, your finger oils are detrimental, so gloves are a must. That's also true in some electronics.

Properly selected, all have their place. Reliability is increased. Ease of repair is increased. Dust can be a problem.
 

AlbertHall

Joined Jun 4, 2014
11,607
Also, on strip down a few years later, the connectors appear to be good, with no signs of corrosion.
However speaking to a guy who repairs motorcycles for a living today, he advised me against it.
<cynical hat on> Maybe he says this as it reduces his potential work and profit.
 

Thread Starter

Tifa

Joined Nov 5, 2009
14
Thanks guys.....from your responses, it's going to be business a usual then.
Agree about grease attracting dust/dirt. I'm pretty careful about how I use it to avoid this.
Cheers.
 

bwilliams60

Joined Nov 18, 2012
1,419
This is always a well debated subject and after 35+ years in the industry, I am still on the fence. Dielectric grease or any grease for that matter is a petroleum based substance and with certain insulation materials, it will cause problems such as the insulation peeling back away from the terminal and leaving copper exposed. There is also the thought that grease attracts dirt which attracts moisture and a whole new can of worms opens up. I like glyptol and krown rustproofing spray which has worked very well for me. The bottom line is, as #12 pointed out, you go with history. If it has always worked for you, why change because "someone said". Also as HP said, get them to tell you why it doesnt work. Most times they can't.
 
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