Dielectric grease correct use?

[tirwin]

So I was reading an article the other day on an automotive topic and as I was reading, the author stated that dielectric grease should be used — because it is conductive.

I always believed that “dielectric” meant it was an insulator and not a conductor. I looked it up, and that indeed seems to be the definition.

So, I did a little more digging. I found other references where other people say it is conductive. Here is one example:

https://www.youtube.com/watch?v=zhl3bLzgq9A

I always thought the purpose of dielectric grease was to cover connections thereby preventing corrosion. For example, using it on the outside surface of battery terminals. I did not think it was supposed to be used on mating surfaces as it would impede conductivity. But this guy seems to advocate using it on connector blocks and alternators where you’d think it wouldn’t be advisable.

One of the recommended uses is spark plug terminals. I get using it to prevent moisture from getting in the boot, but if it is an insulator, then why is it recommended in a high voltage application between the plug and plug wire?

To add more confusion, I had to take Latin when I was in school. The prefix di- has two meanings: 1) “two” and 2) it is the short form of dia- when the first letter is a vowel as in “dielectric”. Di- in this case seems to mean “through”. Wouldn’t this suggest that the meaning would be conductor rather than insulator? Literally, “through electric”.

So what does the Pelican braintrust say? Is it a conductor or insulator? Should it only be used on the outside as a protectant? Ok to use on mating surfaces or not? Are the people who say it conducts electricity better simply mis-stating the facts?

I’m just wondering what the correct/incorrect use really is. Seems there are some urban myths around this topic.

[targa44]

Wikipedia - insulator.

[Bill Douglas]

Stabilant 22 is an electrical contact enhancer, if that's what you are wanting. And it doesn't let the current run to other pins of a multi pin connector.

[timmy2]

Used on electrical connectors for corrosion prevention. Especially dissimilar metals.
I’ve used it in one form or another for 30+ years in the electrical trade. We use it on station batteries, as well as for high voltage applications.

Yes, when thick enough it is an insulator, but when in a compressed connection it doesn’t have any measurable effect. Just works really well to prevent corrosion.

Here is a good article with some testing done.
https://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm

[dannobee]

Insulator. If we needed a grease that conducted we had this stuff. https://www.mgchemicals.com/products/greases-and-lubricants/conductive-greases/silver-conductive-grease-8463
But to use that stuff was extremely rare. And it is rather pricey.

[stownsen914]

I agree there is misinformation out there about dielectric grease. I had the same q at one point and found info. That was all over the place.

[tirwin]

Thanks everyone for the clarification. And glad I’m not the only one who has pondered this.

So to summarize... dielectric grease will not directly improve an electrical connection per se but it’s benefit is to prevent corrosion which could degrade the quality of a connection over time.

That is what I thought. Just seemed confusing that you find people saying it improves conductivity.

[Ctopher]

Yep, I too had read go/nogo on dielectric grease use but not knowing for years and years had applied it to spark plug wires. Later I was told never to use it on plugs, I think I even read a few posts on this site referring to negatives of dielectric grease on plug wires. From what I understand and have read in some tech type articles and fliers it’s mainly helpful as a preventive measure against corrosion. I ran across this a while back on bobistheoilguy forums.

https://www.nyelubricants.com/stuff/contentmgr/files/1/aadcc2c9aef3c2a34bb520cf86312242/en/product_overview___nyogel_760g.pdf

For what it’s worth I’ve used dielectric grease on plug wires, coil pack to spark plugs, electrical connectors and I coat the battery post/terminal prior to mounting. The grease protects and if installed correctly, metal on metal contact will conduct and the rest of the terminal should push out any grease.

CTopher

[walt]

I have always considered this grease an insulator and I use a light coat on spark plug boots. I've heard some use it on certain electrical connectors that can swipe the grease clear when connecting.

[911pcars]

Folks should be aware of a product called SuperLube, a non-silicone, food-grade synthetic grease that contains PTFE (Teflon). Most lubes are petroleum based and can affect various O-ring and sealant materials. Compare with the old standby, Dow/Molycote 111. Both are dielectric greases with good lubrication qualities:

https://www.lubricantspecialty.com/product/molykote-111-compound?gclid=Cj0KCQjw_absBRD1ARIsAO4_D3uTSo8XB2R 3Tfi6I-ukMWPt5LTnJe90nyhU0OQSEVjD7V7T7wwdxxMaAh07EALw_wcB

https://www.super-lube.com/faqs
(a one lb. tub is about $10 from HomeDepot)

Sherwood
(no affiliation)

[gtc]

Cue the Krytox/Molycote debate! Where are Henry and Laprikitis?

[A horse with no name]

A good question Tirwin, including of course Timmy2's reply...Over the years, I too have wondered exactly when to use it.

Question: About once a year I remove the fuses so as to remove some corrosion on them; would applying a thin film on their ends stop this from happening with out any impedance?

Thanks in advance

[timmy2]

Originally Posted by A horse with no name

A good question Tirwin, including of course Timmy2's reply...Over the years, I too have wondered exactly when to use it.

Question: About once a year I remove the fuses so as to remove some corrosion on them; would applying a thin film on their ends stop this from happening with out any impedance?

Thanks in advance

Yes, Just the thinnest layer will work. Better to put it on the fuse posts and springs actually.

[A horse with no name]

Thanks Dennis...I'm sure that, with this info, it will help many fix the ongoing issue with these type of fuse panels... They're 'just' a tad old fashion eh.

[timmy2]

NO-OX ID is some of the best to use.

[A horse with no name]

Good to know... Again, 'Thanks'!

[jjeffries]

That’s great stuff. I bought a can from the old-skool bearing supplier where I bought the bearings to overhaul my steering rack.

Originally Posted by 911pcars

Folks should be aware of a product called SuperLube, a non-silicone, food-grade synthetic grease that contains PTFE (Teflon). Most lubes are petroleum based and can affect various O-ring and sealant materials. Compare with the old standby, Dow/Molycote 111. Both are dielectric greases with good lubrication qualities:

https://www.lubricantspecialty.com/product/molykote-111-compound?gclid=Cj0KCQjw_absBRD1ARIsAO4_D3uTSo8XB2R 3Tfi6I-ukMWPt5LTnJe90nyhU0OQSEVjD7V7T7wwdxxMaAh07EALw_wcB

https://www.super-lube.com/faqs
(a one lb. tub is about $10 from HomeDepot)

Sherwood
(no affiliation)

[Ctopher]

Originally Posted by jjeffries

That’s great stuff. I bought a can from the old-skool bearing supplier where I bought the bearings to overhaul my steering rack.

Is this stuff similar to the 3m Silicon paste but food grade, as in no silicone? I’m always on the look out for another super lube.

https://www.3m.com/3M/en_US/company-us/all-3m-products/~/3M-Silicone-Paste/?N=5002385+3293194053&rt=rud

I’ve started to use the 3m stuff for brake caliper pins and coating rubber and once my little tube of dielectric grease runs out will use in its place.


Edit: I read the FAQ. Looks like a more refined Wurth PTFE/HHS2000/HHSK lube.

CTopher