wire turned black

[fstalfire]

Hello all, I went to wire a new bilge blower tonight and when i stripped back some wire the copper wire has turned black, I assume its from corrosion so i cut some wire off, about a foot, and stripped back the sheathing and again the wire had mostly turned black....at this point I'm curious if I need to replace this wire or is the staining harmless?

 

[Chip Chester]

Re: wire turned black

It would be best to use marine wire, in which each individual strand is separately tinned during manufacture. It prevents the corrosion you've observed.

 

[tpenfield]

Re: wire turned black

Yes, your wiring is not marine grade . . . at least some of it is not. You will have to use steel wool or some metal tarnish remover to get the surfaces back to clean copper. I usually solder any new wiring for the splices/connectors, etc. If you crimp the wiring, then you might want to use a shrink tube and apply some adhesive or epoxy around the connection to keep moisture out.

 

[Bob_VT]

Re: wire turned black

YES replace that wire since it's resistance will be climbing through the roof!! Check ALL of your wires and battery cables for the same issue.

I have found the cheapest place for Marine grade pre-tinned wire is my local Interstate battery store.

 

[fstalfire]

Re: wire turned black

So essentially what was supposed to be a quick, replace blower motor will turn into replacing wires? As far as I can tell this is all OEM bayliner wire... I solder and shrink everything, it's ashame the previous owner didn't

 

[Chip Chester]

Re: wire turned black

Well, this particular wire is a wire that you really want to do its job well. Many others are, too.
It would be worthwhile to check the wiring on nav lights, engine controls and instruments, and signalling devices to verify the proper wire was used. Secondary circuits, like stereo, livewell, and the like could wait. Marine wire is the right way to go, and for the very reason you've witnessed. If Bayliner used something else, well...

It's always possible that a previous owner replaced or added some wiring with whatever was kicking around the shop, or the auto parts store. And most anything will work for a season. Trouble comes when you're a few seasons down the road from the now-forgotten quick repair, and a bilge pump suddenly becomes "mission-critical".

Solder is good if you're good at soldering. Marine shrink tubing (with internal adhesive) is good, too.

 

[dingbat]

Re: wire turned black

It doesn't matter if you use marine (tinned) wire or not. Sooner or later the dreaded black wire disease is going to get you. The tinned wire only delays the inevitable.
Suggestion.
Crimp these on the ends of your bilge pump cables. Connect, then use a good quality heat shrink over the connectors to make a waterproof seal. The connectors make life easy when it comes time to trouble shoot or replace the pump.

http://www.iboats.com/Ancor-Adhesiv...41530470--session_id.459455752--view_id.49214

The other thing is to leave your bilge pump cables as long as possible so you can make the connection outside the bilge area.

 

[Radasaurus]

Re: wire turned black

It doesn't matter if you use marine (tinned) wire or not. Sooner or later the dreaded black wire disease is going to get you. The tinned wire only delays the inevitable.
Suggestion.
Crimp these on the ends of your bilge pump cables. Connect, then use a good quality heat shrink over the connectors to make a waterproof seal. The connectors make life easy when it comes time to trouble shoot or replace the pump.

http://www.iboats.com/Ancor-Adhesiv...41530470--session_id.459455752--view_id.49214

The other thing is to leave your bilge pump cables as long as possible so you can make the connection outside the bilge area.

Exact same thing I have found. My brother calls it Black Death and its literally impossible to avoid. Tinned or not, it travels up the wires - even through the plastic insulation - and when it hits your electronics, it will fry them as well. So every time I do ANY wiring, I check for Black Death now and replace the entire wire if I find any.

No way to stop it and I don't think its mold -- its a strange aggressive corrosion, but if it was mold it would need air to grow and along the insulation it gets no exposure to air, so rule out mold. My brother has messed around with it for 30-40 years and he still has no idea what causes it. I'm bewildered also. Crazy.

 

[alldodge]

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