[ltbarcly3]

The risks of using steel cable for power are going to be corrosion/rust. The primary way this will cause problems is around connections, but long term it is also an issue away from connections. At connections, corrosion can cause the wire to become loose, something like ox-gard can be used to delay this significantly. It isn't designed for steel but some kind of protection must be done at connections or arcing will be a major risk. Longer term the wire itself will rust, and at some point the conductive cross section of the wire will be compromised to the point it overheats and melts. This might be a year and it might be 100 years depending on factors which are hard to predict and control.

TLDR: connections must be protected by some kind of anti oxidation coating, if you have nothing else use grease but something designed for electrical connections is better. If you have nothing else, melt some lead and dip the exposed part of the wire in that to coat it. Lead should be readily available in a war zone? Long term the wire WILL melt at some random point along the wire so it is much better if this wire is kept away from anything flammable.

[codethief]

Maybe you should post this as an answer/comment in the OP?

[hinkley]

> Lead should be readily available in a war zone?

Goddamn, son.

[cbdumas]

You should post this as an answer to the question on stackexchange

[dheera]

It takes effort to sign-up though. Maybe that should be a lesson to stackexchange to not require login to post intelligent content.

[wizzwizz4]

Stack Exchange doesn't require login to post. It just requires an email address (and you can provide a fake one, if you don't have one for whatever reason).

[Gordonjcp]

> The risks of using steel cable for power are going to be corrosion/rust

Probably fine in Sudan in late spring, tbh. They have to pump water up from the ground with electric pumps, hence the need for cabling, so I guess they don't have much rain right now.

[zdragnar]

Sudan gets about 4 inches of rain a year or something like that. It's obscenely hot (compared to what I am accustomed to) and dry. For a temporary solution, rust definitely is not a limiting factor here.

[RheingoldRiver]

Btw, OP clarified in a comment that by "for how how long" they meant distance and not time. They're hoping it's a temporary solution.

[MisterTea]

> It isn't designed for steel but some kind of protection must be done at connections or arcing will be a major risk.

Not so much arcing but resistance between the terminal and the wire will increase as a coating of oxide builds up between the two. Eventually the resistance is high enough that dangerous amounts of heat will build up and ignite wire insulation or other flammable materials. What usually happens, is the conductor was nicked by the electrician during stripping and that becomes a mechanical weak point that becomes a fuse link and the wire sometimes just melts off at that point rapidly without starting a fire and goes open circuit.

> melt some lead and dip the exposed part of the wire in that to coat it.

Plain molten lead isn't going to "wet" the steel wire without some sort of flux. Rosin flux is made from tree sap of a conifer tree so go find a pine tree and harvest some sap.

[jaclaz]

You don't really need "rosin flux", the idea is to remove oxidation, chloridric acid is what was used for tin soldering, "saturated" with zinc.

https://en.wikipedia.org/wiki/Zinc_chloride#As_a_metallurgic...

Though I have no idea if either can be found locally.

[MisterTea]

> Though I have no idea if either can be found locally.

Which is specifically why I mentioned rosin. Though any acid could likely be used so citric acid or something that could work as well.

[jaclaz]

Yep, but I don't think that just acid is good enough.

Choridric acid + Zinc was traditionally used in tin (but lead isn't so much different) soldering/brazing, particularly of copper and brass because the Zinc had some role in the chemical reaction, AFAIK.

[hinkley]

borax?

[genewitch]

I would think that's a different type of "flux" as it's commonly used for cleaning gold and preventing gold from sticking to the crucible. then again, flux is just an acid, so who knows.

[hinkley]

I've been watching too much blacksmithing on Youtube. It can be used for laminating iron, that much I do know. Not sure about brazing.

[ethbr0]

Out of curiosity, does electron flow influence oxidation speed at all?

Or is its speed purely a consequence of temperature + environmental gases?

[rsync]

"Out of curiosity, does electron flow influence oxidation speed at all?"

Oxidation (and reduction) are literally electron flows.

Oxidation is a loss of electrons and reduction is a gain of electrons.

Since the oxidizing material is the anode in this (oxidation "circuit") you can connect a "sacrificial anode" to the material you want to preserve and the electrons will flow from that instead of the (material you want to save).

We have sacrificial anodes connected to our underground propane tank:

http://www.pettank.com/wp-content/uploads/2016/03/cathode-pr...

... which means a bag of magnesium does all the rusting instead of the tank they are connected to.

[ethbr0]

My understanding was that the speed of the reaction was dependent on temperature (and probably pressure/gas mix), and the electron flow was a byproduct rather than driver of the chemical reaction.

But it seems like you can indeed block the reaction from occuring by saturating the surface with enough electrons (i.e. by applying an appropriate amount of current) that it makes oxidation impossible from an electrochemical standpoint.

https://www.corrosionpedia.com/definition/1237/impressed-cur...

(In addition to the more common, passive bolt-on-a-sacrifical-cathode method)

[pitched]

I’ve found that having a charged, exposed cable laying around will start to rust within about 6 months. This is from cheap phone cables so it being copper-coated instead of full copper is likely.

I’ve also heard of cathodic protection or electronic rust proofing doing the opposite though? Maybe it has to do with moving charges vs static charges? Or ground a cable preventing rust vs charging it accelerates rust?

[scotty79]

Maybe if it warms up the cable it could speed up oxidation?

[ethbr0]

It would. I think that's what most people were figuring.

And also, assuming it's wrapped but not encased to cabling standards (e.g. there's oxygen between the insulator and wire, but the insulator itself is contiguous and airtight), oxidation would eventually deplete the available oxygen "inside" the cable, right?

[ltbarcly3]

The plastic on cheap farm cable like this is not going to be air tight, almost certainly isn't water vapor tight, and probably isn't even 'rust tight', in that I've seen rust migrate through plastic coated steel fencing and accumulate on the outside. I wouldn't count on it for anything other than making the rust slightly less obvious.

[jugg1es]

this is an interesting question. Electrical current creates an EM field that could repel water molecules and oxygen ions. Temperature could also slow oxidation down... like I'm trying to imagine a red hot piece of iron rusting. I wouldn't think it would rust as fast as a cold piece of iron.

[ethbr0]

High temperature speeds oxidation. Learned as a consequence of blacksmithing. ;) So red hot iron absolutely rusts, you just beat the (brittle) oxidation off as you work the piece.

[jugg1es]

learned something today - thanks!

[HeyLaughingBoy]

> Temperature could also slow oxidation down

Gonna have to guess that you've never had to replace a car exhaust :-)

[mauvehaus]

Car exhaust is a weird case though. The water vapor in the exhaust condenses on the cold metal. If you drive far enough, you add enough heat to evaporate the water back out. Else, you end up with a bunch of water in the exhaust facilitating the rusting.

In general, you have this problem with cold metal when there's enough humidity to cause condensation. Bare cast iron in an unconditioned space under cover will definitely rust from condensation.

[zmgsabst]

Anodizing (controlled oxidation) is done via water with a current through the piece to anodize.

https://www.youtube.com/watch?v=gIwvLuNzliI

I’d think that charge would create a faster rusting.

[passwordoops]

Great answer. And I love that the TLDR is almost as long as the main text