Dark silver wire

I've had wire that sat for a few years, the ends can oxidize a little ways into the insulation, so when you strip it, you get oxidized wire and it sucks to solder. Not sure if that's what you have.

What you are most likely seeing is tarnished copper. The tarnish must be removed for solder to stick. Try using a little sandpaper or steel wool or a Scotch-Brite pad to scrub the dark coating off. Aluminum wire would be very hard to solder to. Probably impossible for you with what you have for solder and flux. Eric

I agree with what others have replied.

They do make and sell aluminum wire with a copper plating. The stuff is pure shit IMO. If the iron is too hot the super thin copper layer goes into solution with the lead or tin solder and you're trying to solder to aluminum.

The only time I can see using it is when it is terminated in a screw terminal and it will never ever be moved or disturbed in any way from installation to eternity.

The easiest wire to deal with is solid, soft copper, which has been tinned during manufacture. and if it is stranded more strands of fine wire is always better than a few strands of heavier gauge.

Pay attention to your iron tip too. It should take solder evenly all around. Black spots are not good.

Modern tips are hard drawn copper (stiff not soft) and get a plating of Iron, then are tinned. The Iron prevents erosion of the tip in solder but doesn't take solder well itself.

Lead and tin solder are solvents for copper. With large gauge wire you'd never notice it, but with fine wire like AWG 40 you can feed it into a very hot iron and it just disappears until the lead/tin is saturated with the copper. They also make solder with a percent of copper already added for this reason.

Over-heating or leaving the soldering iron on for hours without using it may kill the tip. It needs a fresh coating of new solder from time to time.

I think that is what I have. I salvage things I find or from things I throw away.

Sometimes I will cut the end off and then I find some fresh copper wire.

Andy

I have seen some flexiable aluminum stranded wire that is copper plated. Bought some off ebay that is low voltage or speaker wire. I use it for some radio speakers and the 12 volt power wires. Most of the time the connectors I use are crimp connectors, but have soldered some of it. Seems to take solder ok.

I would have liked for it to be all copper, Not sure how well it will hold up over a numberof years.

I have heard that some of the premade drop cords being sold are made out of the same stuff. Bad thing is if you buy some wire as number 12 gauge, it might only carry current like number 14 or even less. Seems that a few years back some of the big box stores got into trouble over that. Prebably not their real fault, but just got taken by China.

Some things comming in from China are ok, but I have a feeling they are dumping their toxic waste on up like the dry wall a few years back. It off gassed and ate up the copper in the wiring in the houses.

Aluminium wire is versy hard to solder

An easy chemical test for aluminium is caustic soda (sodium hydroxide) solution, which will dissolve it (but doesn't touch most other metals). there will be a vigorous chemical reaction and hydrogen gas (and corrisive vapour) will be produced, the resulting mixture will be colourless.

Tin plated copper is also common in consumer electronics, if badly oxidised it can be hard to solder, but using more flux will usully suffice to make a good joint

Yup. Old, cheap PVC insulated stranded wire is the worst. I have a couple of thousand feet of it lying around, in assorted colours.

The solution is to use Kester 44 solder, which has RA flux. In fact, Kester 44 plus a needle-tipped bottle of RA flux (MG Chemicals 835) is Good Medicine for this problem.

Cheers

Phil Hobbs