Corrosion on heavy gauge wire

[fixit7]

I was using this to go to a 2 plug outlet.

The corrosion bugs me even though the resistance is 1.0-1.6 ohms.

I have flux on order for my electronics (NT ZJ-18 150g Yellow paste Advance Quality Solder Flux Soldering Paste High Intensity Free Rosin)

Would that help in this case?

I had to return a whole role of automotive wire that was black throughout the entire 11 feet of wire.

Does copper wire have a short life?

[Brumby]

Generally, copper wire should last for quite a long time.  I've had stuff sitting in my garage for 10 years or more and I only need to nip off 1 centimetre (if that) to be greeted with pristine shiny copper on the outside of the strands.

What WILL cause problems is when it is being kept in an environment that is less than ideal.  This can include - but is not limited to - high moisture conditions and rubbish insulation.  Severe age can be a contributing factor, but for the whole 11 feet to be black would concern me.

The fact that the resistance is low indicates it will still perform as a conductor, but termination would be a concern - because even if you did clean it up, I wouldn't feel comfortable unless I checked the connection a few times over a period of time.

Truth is, though, if it looked like that, I wouldn't want to use it.


I'm sure there will be others who can offer more opinions and experiences.....

[Brumby]

Temperature!   Yes, of course, temperatures - but usually towards the upper end or outside the "habitable zone".   

[fixit7]

Generally, copper wire should last for quite a long time.  I've had stuff sitting in my garage for 10 years or more and I only need to nip off 1 centimetre (if that) to be greeted with pristine shiny copper on the outside of the strands.

What WILL cause problems is when it is being kept in an environment that is less than ideal.  This can include - but is not limited to - high moisture conditions and rubbish insulation.  Severe age can be a contributing factor, but for the whole 11 feet to be black would concern me.

The fact that the resistance is low indicates it will still perform as a conductor, but termination would be a concern - because even if you did clean it up, I wouldn't feel comfortable unless I checked the connection a few times over a period of time.

Truth is, though, if it looked like that, I wouldn't want to use it.


I'm sure there will be others who can offer more opinions and experiences.....

I remembered that I had some HCl. I made about a 15% solution and soaked the ends of the stripped wires in it for a minute.

I thoroughly washed it and then sprayed it with a strong solution of sodium bicarbonate to neutralized the acid.

I used a strip of ph paper to verify that the ph was at or below 7.0.

The treatment restored the copper color throughout, though it is not shiny.

I expected that.

Andy

[Ian.M]

... and now you probably have traces of salt and acid up under the insulation that wicked up there when you immersed the end.   Odds are, its going to die within a year or two.   

[fixit7]

... and now you probably have traces of salt and acid up under the insulation that wicked up there when you immersed the end.   Odds are, its going to die within a year or two.

<I made about a 15% solution and soaked the ends of the stripped wires in it for a minute.

No acid entered insulation.

Insulation was at least 2 inches above the bare wire.

[Ian.M]

The question is how far does an aqueous solution wick up bare stranded wire by capillary action?  Unless you separated and fanned the strands (to eliminate the small gaps capillary action needs) before dipping them, and took care to always keep it strands down till fully rinsed, there's still a significant risk there's salt and acid under the insulation.

[Gyro]

For goodness sake stop messing about with chemicals and do it properly. Strip the whole cable back until you reach clean, un-coroded cores. If you still find corrosion after a couple of inches then the cable is no longer fit for use.

[james_s]

I've encountered wire where something in tbe insulstion leaches out and corrodes the copper. I've seen this most often in automotive applications, particularly wiring in the engine compartment that is exposed to high heat.

[David Hess]

Kester used to sell small bottles of their Copper-Nu which works well for cleaning or soldering tarnished copper.  But I do not see anybody selling it in small quantities now.

[Jwillis]

If you have a fairly strong acid like hydrocloric or even lemon juice .Just dip the ends into the acid until the tarnish is a gone then rinse with water and dry well .Solder as usual . If your wire is tarnished badly for the length of wire,that indicates poor sealing against moisture. Capillary action  draws moisture along the full length  . This can lead to corrosion severing the wire later on if theirs still moisture inside the shielding. And with an electrical charge running through the wire it's much worse .In the long term it would be advisable to just replace the wire and seal the ends with shrink wrap or rubber electrical paste.
In the case of wire connections that are exposed to long term constant exposure to moisture I prefer to solder the connections.Although there will be objections with arguments of wicking that can  weaken connections there are benefits to  it because it blocks moisture from entering the wire at the connection end.You don't need a lot of solder just enough to seal and weld non-welded crimp connections. If done correctly wicking won't happen and the connection will be better and last longer.