Power cords with wires impossible to solder - Page 1
Forum section: electronics / beginners

author: SnipTheCat
author_rank: Unknown
timestamp: October 03, 2016, 09:13:12 pm
content: I have been asking myself for a long time about this and didn't really find answer, and since I make my own power cords I am less faced with the problem than before.The problem is that those power cords seems to have pretty dark wires (multibrain), When you try to solder you can some bubling and a lot of dirt as you cet with enamelled wires, but here the soldering doesn't stick to it. If you are patient enough you may have something that seems soldered, but usually you pull it apart quite easily. I have tried flux, no help, tried higher soldering temperature, no help...Anyone knows any magic for those?

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 03, 2016, 09:21:07 pm
content: scrap off the blackish thing with knife..

author: Monkeh
author_rank: Super Contributor
timestamp: October 03, 2016, 09:22:14 pm
content: Get some decent cables.

author: Monkeh
author_rank: Super Contributor
timestamp: October 03, 2016, 09:28:02 pm
content: s/high quality/normal quality/

author: SL4P
author_rank: Super Contributor
timestamp: October 03, 2016, 09:35:43 pm
content: To increase flexibility, some wires are spun around, or interleaved with fibre/glass threads, these are notoriously hard to solder, and are designed to be welded or crimped - not soldered.

author: stj
author_rank: Super Contributor
timestamp: October 03, 2016, 09:57:03 pm
content: maybe using crimp bootlace-ferrules would help.if you do, get a 6-sided crimp tool - not a 4-sided one.like this:http://www.ebay.co.uk/itm/141578568204

author: SnipTheCat
author_rank: Unknown
timestamp: October 03, 2016, 10:17:20 pm
content: Thanks for all the quick replies :-) I would think of the oxidized/impure copper... I have also seen those cables interleaved with fiber, they are also a pain to solder. I guess I'll just get decent cables instead to try to reuse crap... What is sad is that these had preddy decent gauge (~1mm^2 per wire)About scrapping the dark parts or even trying vinegar+salt I had very very little success

author: tautech
author_rank: Super Contributor
timestamp: October 03, 2016, 10:24:04 pm
content: Quote from: SnipTheCat on October 03, 2016, 10:17:20 pmSometimes a solder with a more aggressive flix can save the day, along with a much hotter iron.A bit of a fiddle with some snippets can usually find a solution.When all else fails scraping the conductors to shine them up can and does sometimes work or you'll have to resort to crimping ferrules or some other suitable terminal.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 03, 2016, 10:25:46 pm
content: Probably copper coated aluminium (CCA) which is evil.Chop it & replace with proper wire.

author: bitslice
author_rank: Frequent Contributor
timestamp: October 03, 2016, 11:19:49 pm
content: Quote from: stj on October 03, 2016, 09:57:03 pmThanks for that,I was looking for a bootlace crimper but didn't realise they did hex versions in that size

author: Audioguru
author_rank: Super Contributor
timestamp: October 03, 2016, 11:37:06 pm
content: Copper wires that have been wet for a long time have black copper that is hard to solder to.

author: SnipTheCat
author_rank: Unknown
timestamp: October 04, 2016, 11:29:59 am
content: Quote from: mikeselectricstuff on October 03, 2016, 10:25:46 pmI have the feeling that's what it was... anyway, tossed it away and got proper cable ;-)

author: Lightages
author_rank: Unknown
timestamp: October 04, 2016, 03:20:16 pm
content: I have also seen many cables with copper coated steel wire.

author: rob42
author_rank: Newbie
timestamp: October 04, 2016, 04:50:46 pm
content: try aspirin or other active flux

author: george.b
author_rank: Frequent Contributor
timestamp: October 04, 2016, 05:16:36 pm
content: Quote from: rob42 on October 04, 2016, 04:50:46 pmAspirin?

author: Len
author_rank: Frequent Contributor
timestamp: October 04, 2016, 05:38:17 pm
content: Quote from: george.b on October 04, 2016, 05:16:36 pmIf soldering is giving you a headache, take aspirin and use a good flux.

author: Monkeh
author_rank: Super Contributor
timestamp: October 04, 2016, 07:02:02 pm
content: Quote from: george.b on October 04, 2016, 05:16:36 pmWorks really well. Say goodbye to your tip, too.

author: electr_peter
author_rank: Unknown
timestamp: October 04, 2016, 08:01:54 pm
content: Quote from: mikeselectricstuff on October 03, 2016, 10:25:46 pmQuote from: Lightages on October 04, 2016, 03:20:16 pmMetal strands can be made out of steel - check with magnet. Or it can be CCA, as Mike mentioned.Either way, I would toss this cable out and get proper cable with copper strands. Copper clad aluminium or steel is not good in mains power cables (it is a desperate cost saving measure from a manufacturer, which results in very high resistance cable).

author: stj
author_rank: Super Contributor
timestamp: October 04, 2016, 09:14:25 pm
content: could make a good flexable heating element!

author: george.b
author_rank: Frequent Contributor
timestamp: October 05, 2016, 07:15:07 am
content: Quote from: Monkeh on October 04, 2016, 07:02:02 pmNo kidding? Gotta try that one, sometime. Who knows when such a trick might come in handy...

author: rob42
author_rank: Newbie
timestamp: October 05, 2016, 01:46:13 pm
content: Quoteits just acetylsalicylic acid, you can use any other weak acid, like orthophosphor, acetic (vinegar), formic etc.or weak organic (used in no-clean fluxes): palmitic, oleic, succinic, glutaric, paraffine / stearine, glycerine...

author: george.b
author_rank: Frequent Contributor
timestamp: October 06, 2016, 02:53:11 am
content: Quote from: rob42 on October 05, 2016, 01:46:13 pmI know, but I thought it would decompose at soldering temperatures, didn't imagine it'd work!

author: helius
author_rank: Super Contributor
timestamp: October 06, 2016, 03:09:10 am
content: It may decompose, but it is an ester, so if it hydrolyzes at the ester bond it will produce two other acids: salicylic and acetic. I think water soluble fluxes frequently contain similar esters.

author: george.b
author_rank: Frequent Contributor
timestamp: October 06, 2016, 04:06:23 am
content: Aha, I see. Chemistry is not my strong suitthanks!

author: johansen
author_rank: Super Contributor
timestamp: October 06, 2016, 04:18:21 am
content: Quote from: blueskull on October 03, 2016, 09:27:22 pmIf they add the phosphorous as some kind of deoxidiser or something, that might make sense.But its hard to believe there would be enough beryllium in there to prevent it from soldering. unless they dumped a metric ton of relay contacts in with the 10 tons of copper. but i don't think that would be enough.. also if someone did have a metric ton of relay contacts, it would be recycled for the beryllium and silver, not dumped in a copper melt.but if someone were to melt down 100 tons of power strips.. there would be enough brass in with the copper cord to raise the resistance to unreasonable levels.. however, still no berylliumI have run across some 10 ohm, 6 foot long, iec power cords. not making that up. the servers they came with only pulled about 100 watts, so they would have survived, and their resistance was discovered after finding one of them was open circuit. the wires were not magnetic, had a color somewhere between brass and light brown..

author: rob42
author_rank: Newbie
timestamp: October 06, 2016, 04:56:01 am
content: I have used several times wires with inferior solderability, looked more yellowish, and not so flexible as a pure copper.maybe, some brass-type alloy.