Protective grease/spray for power terminals

[marchem]

This is my week for blasting the forum. That's what happens when I take a week off from work to finally do this big boat electrical project. Thanks to all for their advice.

Stupid question, but when connecting larger cables to terminals (or even small ones) what's the best process for applying protective grease/spray, and what are people's preferred products? Lube it up before or after assembly?

 

[Justin_NSA]

Practical Sailor had an article on spray-on protection if you have access
https://www.practical-sailor.com/is...t-Electrical-Equipment-Protection_5502-1.html

 

[marchem]

Practical Sailor had an article on spray-on protection if you have access
https://www.practical-sailor.com/is...t-Electrical-Equipment-Protection_5502-1.html

Thanks. I've read all of their articles. I'm also interested in what people here have experienced.

 

[Justin_NSA]

It was recommended somewhere to use Noalox. Haven't checked lately to see how it's working.
You can get it anywhere they sell wire terminations

 

[pateco]

Has anyone had experience with the TC-11 product recommended by Practical Sailor?

 

[Ralph Johnstone]

when connecting larger cables to terminals (or even small ones) what's the best process for applying protective grease/spray,

Simplest thing I've found is Vaseline applied BEFORE connecting terminals. Battery studs and terminals are like new after years of service.

Of course, almost every other product has superior cost and properties to Vaseline so ....................................

 

[gettinthere]

I like Boeshield T9 for electrical connections. It was formulated for that by Boeing. Have not used it on battery terminals. Actually, I use "nothing" on my 5 battery house bank terminals and have not seen any corrosion of any type in 8 years of full time use.

 

[JK_Boston_Catalina310]

I use dielectric grease. I dry fit everything and then apply the grease on the lugs and posts. Not pretty looking but effective .

 

[RoyS]

Dielectric grease is non-conductive.

 

[py26129]

If you have a little time, I found this dissertation on dielectric vs. conductive grease. It's not specific to boats but it quite detailed and I believe the principles will apply.

https://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm

Matt

 

[marchem]

I use dielectric grease. I dry fit everything and then apply the grease on the lugs and posts. Not pretty looking but effective .

Thanks. Makes a lot of sense to me.

 

[JK_Boston_Catalina310]

Dielectric grease is non-conductive.

Your point?

 

[SG]

Your point?

If you are simply covering the outside of the terminal connection, the substance is okay as long as you don’t get it into the “contact” surfaces. If it’s in or on the contract sufaces, it will retard (rather than enhance) performance.

 

[RoyS]

J.K., An Ohmmeter (as described in the article above) will not accurately indicate the integrity of a battery terminal connection. The terminal is (relatively speaking) huge in surface area in order to conduct the large current required when starting. Applying non-conductive grease to such a connection will only serve to limit the current flow. I believe that the original idea of applying grease to lead to lead battery connections came from the distant past when such connections in automobiles were prone to developing a white build-up of corrosion on the outside. This was probably due to the leaking caps on the cells splashing acid about. In any case, in those days the grease was suggested to be applied only on the outside as a paint, if you will. With a boat, the battery terminals are usually disconnected and cleaned annually and the cell caps, if present at all, are not prone to spillage. My point is that there is no need to coat or much less apply grease inside such a lead to lead high current connection.

 

[walmsleyc]

Did you guys read the article?

"In single low-voltage terminals or connections, such as metal-to-metal joints, grounds, or battery posts, almost any pure grease of light viscosity will be acceptable. Caution should be used with greases containing metallic powders to be sure any metal is compatible with the embedded grease metal. Connection enhancement from embedded metal powder is very minor, if it exists at all, and there is increased risk of bad connections if the metal powder has any interaction with the base metals."

The article basically says that reasonably suitable grease will not interfere with the electrical contact or current carrying ability of the connection. It wont retard any current, or cause a voltage drop.

Chris