Replating Electrical Terminals

Thread Starter

bwilliams60

Joined Nov 18, 2012
1,350
I am looking for a solution to an automotive problem if anyone has any suggestions. I work with components that have exposure to salt and corrosion and it ends with large terminals and posts becoming oxidized and suffering from the green monster. Does anyone know of a home replating method for large terminals or a coating that can be used to protect the terminal from further oxidation once it has been cleaned? When I clean these off, they are just copper terminals with plating eaten away. Suggestions? Imwould like something that will last for quite some time and have a similar finish
 

SamR

Joined Mar 19, 2019
2,812
I can't remember the name, something like Noalox?, that we used on copper conductor terminations. The plant was literally only a few hundred feet from the salt marshes in GA and oxidation corrosion was a problem so our maintenance and construction crews were required to use it. Similar or the same stuff that is required when terminating aluminum power conductors. A red grease-like material. Looked in McMaster-Carr and nothing rang a bell with me. Noalox says it's good for copper as well as aluminum so that may be it.
 

SgtWookie

Joined Jul 17, 2007
22,220
Search for "tin plating liquid" on the Web. Not exactly cheap, but quick to use. It's routinely used to tin copper PCB's. The plating won't be very thick. If you need a thicker plating, get yourself a solder pot, and hot-dip your connectors.
 

MisterBill2

Joined Jan 23, 2018
7,327
There is a product called "anti-corrosion grease" which looks a lot like wheel bearing grease, and it tends to stay on places where I apply it. The main benefit is it keeps air and moisture of of whatever I smear it on. NoAlOx is a good material to use with ALUMINUM wires or terminals to prevent the typical aluminum failure that otherwise always happens. The red battery terminal grease works and contains an additive to reduce acid vapor damage.
And at least one auto company had a gease made just or protecting the electrical connectors that went through the vehicle firewall. That stuff was very sticky, but it did work very well.
 

shortbus

Joined Sep 30, 2009
8,057
Having worked at Delphi/Packard, most of the terminals are tin plated. Some with gold on certain parts of the terminal. If your wanting to actually replate these are the guys to contact - https://caswellplating.com/electrop...-plating-kits/nickel-electroplating-kits.html

Can't you just replace the terminals in question? Should be cheaper and easier than replating. On the firewall connectors we made they used a DuPont silicone grease to stop corrosion. They pumped the same grease into spark plug boots too.
 

Thread Starter

bwilliams60

Joined Nov 18, 2012
1,350
@shortbus, I would love to be able to just replace these terminals but as you can see from the pictures, it may not be that easy. Very hard to find the source of such pieces as you must know coming from Delphi and the secret compilations of OEM proprietary data. I need to coat the large terminal and sometimes replace some of the smaller terminals around it due to corrosion. I usually steal them from another board.
 

Attachments

MaxHeadRoom

Joined Jul 18, 2013
21,639
" Permatex Dielectric Grease protects electrical connections against corrosion"
But do not apply to mating surfaces of an electrical connection. As it is also an insulator,
But can be applied after the connection is made, very good at defeating electrical based corrosion.
Max.

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MisterBill2

Joined Jan 23, 2018
7,327
I have seen plating pens marketed, but not recently. That would be one option. Unfortunately I have no experience with them at all, but possibly others do have some experience. Of course the way to solve the problem is to make the connections and then prevent any future corrosion by adequately protecting the items. THAT may be a rather hard task, I admit.
 

Thread Starter

bwilliams60

Joined Nov 18, 2012
1,350
I have been using dielectric for quite a number of years now with great success but I guess I should have told the front end of the story. I rebuild automotive modules and this one in particular has a terminal that is often exposed to corrosion and never coated during a new vehicle pre-inspection so after a few years of use, the unit fails and comes to me for repair/rebuild. Rather than put this ugly terminal back out there, I would like to re-coat it so that it looks new and send along a packet of dielectric grease for prevention once it has been reconnected. Right now I am looking at plating options but Dielectric is a great preventative.
 

sagor

Joined Mar 10, 2019
284
Add to what Max says in #10, there is heat shrink tubing that has hot melt glue already coated on the insides, and when you shrink the tubing, the glue melts and flows around the connections. This is fairly waterproof, and good for small connections. If buying this stuff, look for the 3:1 shrink ration, it shrinks more than the 2:1 tubing. But, if 2:1 works, fine....
 

SamR

Joined Mar 19, 2019
2,812
I have also used the shrink tubing w/ glue for submerged saltwater use and it lasted for years. In fact, it was still good when I retired the boat years later.
 

shortbus

Joined Sep 30, 2009
8,057
Very hard to find the source of such pieces as you must know coming from Delphi and the secret compilations of OEM proprietary data. I need to coat the large terminal
OK, I thought you were talking terminations at the end of a wire. Delphi does sell almost all of their products or did but you had to buy in whole reel quantities. That terminal is probably proprietary.

How about this kit? https://caswellplating.com/plug-n-plate-tin-kit.html It's been quite a while since I looked at Caswell's site, boy have prices went up. But their products are the go to ones or used to be.
 

Thread Starter

bwilliams60

Joined Nov 18, 2012
1,350
We have an electrplating company not far from us. I am checking to see what kind of pricing they offer. Maybe I will nust take up chemistry and make my own. Its not that difficult. Just don't have the time. @shortbus I can source about 90% of all automotive terminals being used right now. Its not that difficult once you figure out who the manufacturers are. Mouser carries a good deal of them, especially Delphi and Tyco
 

MisterBill2

Joined Jan 23, 2018
7,327
I have seen a plating handbook that describes HOW to plate for plating shop use. All the way to details like bath temperature and amps per square inch, for electroplating. So one does not need to study chemistry, which is a huge career, but just to get hold of cookbook on how to do it.
 

shortbus

Joined Sep 30, 2009
8,057
We have an electrplating company not far from us. I am checking to see what kind of pricing they offer.
But they probably would need you to remove the terminal from the board. The kit I linked to the plating could be done on the board, it's a *brush* type plater. They used to be popular back in the day, could be had in silver, gold, copper, etc.

That said, if you remove the terminal from the board I'd think that tinning it with lead would be a cheaper and more robust solution. http://www.johnsonmfg.com/temp/tinning.htm I've used that brand for doing lead work on old car bodies, you have to tin the surface before starting to build up the lead, or the lead won't stick to the steel. They also have it in lead free. just heat the removed terminal with a propane torch and brush the butter on and wipe it off.
 

MisterBill2

Joined Jan 23, 2018
7,327
The terminal in the picture looked a lot like copper with a faded tin plating. I know that there is electroless tin plating used on PC boards much of the time, and so possibly that may provide a useful link to something.
 
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