Any tricks for wire corrosion

vroom ZOOM

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Aug 15, 2017
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414
Hi, I am working on the wiring on my boat. Some plugs got wet and the wires started to tarnish. No green corrosion, but the wires do have that black oxide coating on them.

1. Is there some kind of crap I can buy that will soak up the wire and stop the corrosion?
2. How long will these wires last if I just clean up the ends to shiny copper and put new plugs on?

Idk - maybe I am overthinking this too much. I was going to grab some contact cleaner and clean the ends up some.

Need your thoughts on this.
Thanks!
 

airshot

Vice Admiral
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Jul 22, 2008
Messages
5,081
I can only say that I seal or coat all my connections with shrink tubes with sealant or keep a good coat of dow 111 silicone grease covering the wires. So far no corrosion issues after 15 years. I had boat trailer wires that turned black from dunking in the water. After sealing all the connections the black stopped.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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49,548
Hi, I am working on the wiring on my boat. Some plugs got wet and the wires started to tarnish. No green corrosion, but the wires do have that black oxide coating on them.

1. Is there some kind of crap I can buy that will soak up the wire and stop the corrosion?
2. How long will these wires last if I just clean up the ends to shiny copper and put new plugs on?

Idk - maybe I am overthinking this too much. I was going to grab some contact cleaner and clean the ends up some.

Need your thoughts on this.
Thanks!
1 - NO
2 - depends on the type of corrosion

quality tinned marine wire would not corrode like that, however cheap wire does. unfortunately most boat builders use cheap wire because as long as the boat lasts longer than the 5 year warranty period, that is all that matters. boats are designed to last about 15 years
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
16,074
Hi, I am working on the wiring on my boat. Some plugs got wet and the wires started to tarnish. No green corrosion, but the wires do have that black oxide coating on them.

1. Is there some kind of crap I can buy that will soak up the wire and stop the corrosion?
2. How long will these wires last if I just clean up the ends to shiny copper and put new plugs on?

Idk - maybe I am overthinking this too much. I was going to grab some contact cleaner and clean the ends up some.

Need your thoughts on this.
Thanks!

The dreaded “black wire” disease is a cancer. Once it takes hold your done.

It will continue to wick up the wire and there is nothing you can do to stop or slow it. It will spread until removed or the circuit fails outright from the buildup of resistance.

Copper terminations turn green naturally over time.. It’s the protective patina that protects copper from further corrosion

Old days you sprayed a coat of insulating varnish and hoped for the best. Now a days “marine” grade termination hardware is either gold or nickel plated.

A bit of advance from someone with 40 years of electronics manufacturing behind them…..do yourself a favor and use Ancor marine heat shrink terminations or equal .

Industrial quality, epoxy lined heal shrink will work as well but the cheap, heat shrink you buy at the big box stores is junk and should be avoided except in emergencies.

Don’t get me started on the use of the so-called “liquid wire” insulations…..the butt of industry jokes and a sure sign an amateur has been at work.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,844
Clean 'em up as best as possible and then apply good quality connectors, butt splices etc. I like the ones with the heat shrink tube, as they can (not always are) moisture proof.

Some will argue for crimp on connectors, but you need special crimpers, connectors and technique. I like to solder the connectors to the wire and cover with shrink tube. I also crimp and solder butt splices, and cover them with shrink tube, for connections I want to last a long time.

You will need a large wattage soldering iron (80W is good), and rosin core solder and flux, to have a chance to solder those older copper wires.

Marine wire is a very good idea, as the tin on each strand helps keep the wire clean enough to solder.
 

vroom ZOOM

Chief Petty Officer
Joined
Aug 15, 2017
Messages
414
1 - NO
2 - depends on the type of corrosion

quality tinned marine wire would not corrode like that, however cheap wire does. unfortunately most boat builders use cheap wire because as long as the boat lasts longer than the 5 year warranty period, that is all that matters. boats are designed to last about 15 years
It says it is marine grade on the jacket, but it sure as hell isn't tinned. I will post some pics of the wires later today.
 

vroom ZOOM

Chief Petty Officer
Joined
Aug 15, 2017
Messages
414
Clean 'em up as best as possible and then apply good quality connectors, butt splices etc. I like the ones with the heat shrink tube, as they can (not always are) moisture proof.

Some will argue for crimp on connectors, but you need special crimpers, connectors and technique. I like to solder the connectors to the wire and cover with shrink tube. I also crimp and solder butt splices, and cover them with shrink tube, for connections I want to last a long time.

You will need a large wattage soldering iron (80W is good), and rosin core solder and flux, to have a chance to solder those older copper wires.

Marine wire is a very good idea, as the tin on each strand helps keep the wire clean enough to solder.
Older? how does 2017 sound? oof! I am basically stuck with metri-pak 280 plugs, these plugs are the only ones compatible with my fuse box. They do have waterproof seals, but water somehow made it past those seals. And yes, it was saltwater. Some wires are shiny copper but others are turning black. I could just replace the entire harness, but that is a big project.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
16,074
It says it is marine grade on the jacket, but it sure as hell isn't tinned. I will post some pics of the wires later today.
Black wire disease (corrosion) is the result of oxygen and moisture in contact with the copper stranding.

While it makes soldering easier, the primary intent of tinned wire is to coat the copper wire with a thin layer of tin to keep oxygen and moisture away from the strands.

Problem being anytime you cut or nick a strand of copper you’ve compromised the tin’s protective coating. Ideally, you shoukd solder dip each cut wire prior to making your crimp connection to restore the protective coating.
 

airshot

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Jul 22, 2008
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When I use shrink tube, I always squeeze some silicone grease inside before shrinking the tube. As it shrinks the excess grease is forced out and seals the connection. So far no issues with any of those connections, some are 15 years old. Today you can buy shrink tubes with a sealant already inside, have only used those a couple times fairly recent so no idea in long term life.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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been using epoxy lined heat shrink for decades. great stuff
 

04fxdwgi25

Chief Petty Officer
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Mar 25, 2022
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Once that starts, only way to stop it is cut it back to clean copper. Solder won't even stick to it.
If replacing it, used the good marine tinned wire.

A stop gap I have seen used and actually works. IF the wire is in good shape, aside from the black, is to get some of the grease they use on the neg 48 volt battery plants in telecom facilities. Apply that to the wire before inserting in a solderless connector, then crimp and use sealing shrink tube.

I apply that grease to all connections on boats and trailers, even battery terminals, and have zero corrosion or continuity problems.
 

Chris1956

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Mar 25, 2004
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Gee, the best answer I know of, is to clean them up with fine sandpaper. The finer the better, separate the strands to get the corrosion off. As far as I know there is no chemical shortcut Then tin them with a large soldering iron, using plenty of flux. Flux new crimp on connectors and crimp, solder and shrink 'em. I welcome a better solution, as this one is a PIA.
 

04fxdwgi25

Chief Petty Officer
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Mar 25, 2022
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537
Never had any luck cleaning them up with sandpaper and trying to get solder to stick.

Best fix is cut it out and replace.
 

dingbat

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Nov 20, 2001
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16,074
Here is a chemical solution if the wires are not too far gone:

This process uses two solutions. One is table salt and white vinegar. The other is baking soda and water.

The salt and Vinegar solution works well to remove the "green" saltwater corrosion from chrome plated fishing tackle as well.

Step 1: Strip the wire(s) to be cleaned.

Step 2: Get 2 containers. They can be paper cups, plastic, glass, bowls, whatever you can find.

Step 3: Put 1 tablespoon of salt in one of the containers. Fill with vinegar and stir. Put as much salt in the vinegar as will dissolve.

Step 4: Put 1 tablespoon of baking soda in the other container. Fill with water and stir. Add enough baking soda to make the water cloudy. The amount is not important, as long as it is alkaline to neutralize the vinegar solution.

Step 5: Put the stripped end of the wire in the vinegar solution. Stirring the wire in the solution helps speed up the process.

Step 6: A couple minutes later the wire will look like new. Leave it in the solution longer if it is not perfectly clean throughout.

Step 7: Once the wire is satisfactorily clean, dip wire in the baking soda water for 10 seconds or so to neutralize the vinager/salt solution.
 
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