Artic blue vs tinned copper wire

[KompetentKrew]

On previous threads here I believe I've seen tinned copper wire advocated as the best for 12v wiring and artic blue as the best for 240v wiring.

My understanding is that tinned copper wire is less likely to corrode, but artic blue seems to be only available in plain stranded copper.

Am I overlooking a variation of artic blue, or is there a reason that 240v cabling is less likely to be affected? Or am I overthinking it and it doesn't really matter that much?

 

[TernVI]

You should keep mains wiring dry.
If corrosion is a problem, it's already dangerous.

 

[matt1]

I don't believe you can get marinised arctic cable. I used tinned cable on 12v and std arctic on 240v when I built my boat. Even a little outer corrosion on the arctic cable is unlikely to affect it - it has many copper strands and voltage drop isn't going to be an issue. If you really wanted tinned throughout you would have to use battery cable for the 240v which I would imagine would be very expensive.

 

[jwilson]

You should keep mains wiring dry.
If corrosion is a problem, it's already dangerous.

Open up either end of any in-use shorepower cable and unless it's near brand new I'll lay odds that the copper wire strands inside are going black - corrosion. You often have to cut off a metre or more of the cable to get back to copper colour.

 

[TernVI]

Open up either end of any in-use shorepower cable and unless it's near brand new I'll lay odds that the copper wire strands inside are going black - corrosion. You often have to cut off a metre or more of the cable to get back to copper colour.

A little bit of black on the surface of a copper wire is not a corrosion problem.

 

[Graham_Wright]

A little bit of black on the surface of a copper wire is not a corrosion problem.

What is it then?

 

[Boater Sam]

What is it then?

Its surface corrosion but the amount that it reduces the cross sectional area of the conductor is minimal.

For any wiring outside in the weather a good spraying with varnish on all terminations when first made is a good idea. Multi stranded conductors act like a wick and suck in water at the ends by capillary action.
All admiralty wiring is coated with a conformal varnish when new.

A silicone spray works well too.

 

[RupertW]

A little bit of black on the surface of a copper wire is not a corrosion problem.

I certainly see it as that but admit I mostly cut off only a small amount then use a Stanley knife to scrape the splayed ends until they are shiny based on the idea that the rest of the bad contacts inside are still almost perfectly conducting strands which will join together uncorroded after a small distance. But I am not so precious about small voltage losses in AC compared to DC as I have only a finite source of the latter.

 

[dankilb]

If you add some solder to the stripped ends doesn’t that effectively ‘tin’ the cable? (courtesy of Mads on SailLife!)

Not that I’d bother with that... although I’m about to do some 240v re-wiring and I will leave some extra slack in the cables in case any corrosion subsequently needs trimming ??

 

[PaulRainbow]

Non-tinned cable is fine for a shore power lead, just the same is it's fine for the extension lead in the garage, the one in the garden, the electric mower cable etc etc etc. Before anyone starts shouting "harsh marine environment", i'm pretty sure all of the people who live on the coast use the same cable as people living inland

Surface oxidation is not going to cause a problem (unless it's extreme and has pitted the cable), current will still flow through the strands, electrickery flows through the whole cross section of the strands, not just along the surfaces. Minor oxidation might reduce the effective cross section area by a tiny amount, but we are using (or should be using) 2.5mm cable with has almost twice the current carrying capacity required for our 16a supplies and voltage drop is pretty much insignificant (our AC supply voltage is roughly 20 times that of our DC power, so voltage drop on our AC is roughly 1/20th that of our DC, about 0.2% on a 5m shore power cable.

** Pedants please note, figures are ball park for a boat with 12v systems and a 16a shore power supply ?

 

[PCUK]

Domestic three core used on 12 volt doesn't suffer from serious corrosion. The perceived problem is breakage from vibration. 30 years on I've not had any bteakages.

 

[Gary Fox]

The annoying thing about the surface blackening is trying to tin it for soldering

 

[penberth3]

If you add some solder to the stripped ends doesn’t that effectively ‘tin’ the cable? (courtesy of Mads on SailLife!)

Not that I’d bother with that... although I’m about to do some 240v re-wiring and I will leave some extra slack in the cables in case any corrosion subsequently needs trimming ??

It would on the bit you can see. It would also remove the flexibility and the strands would be more likely to break.

 

[PaulRainbow]

If you add some solder to the stripped ends doesn’t that effectively ‘tin’ the cable? (courtesy of Mads on SailLife!)

Not that I’d bother with that... although I’m about to do some 240v re-wiring and I will leave some extra slack in the cables in case any corrosion subsequently needs trimming ??

Best bet is to crimp bootlace ferrules onto the wires, this way the conductors within the ferrule won't oxidise.