Wire in effect that won't take solder?

[JJGross]

I'm working on a Marshall compressor and some of the wires used in this thing won't take solder.
They look like they have some kind of black coating on the strands. When heated with my soldering iron, the black stuff bubbles a little like some kind of oil or something. That must be why many of the wires are in little plugs with crimp pins and soldered on the pins. I'm yanking out some of the pins because they're badly corroded (why I'm working on it).

Any way to make these wires solderable or am I looking at replacing them? Some way to clean them?
Should I dip the ends of them in FeCl to etch them a little?
I tried rubbing alcohol, but even after a 10 minute soak it didn't remove the black stuff from the wire strands.

Cheers

[dai h.]

I was able to clean up some of the blackened stuff (which I think is oxidation) from the switch contacts on an old Amdek delay by spraying Deoxit on them and putting them in a plastic container overnight. (There is a tech article on the Caig site suggesting this.) So you might try putting in a bag or container that barely fits the item you are trying to remove the oxidation from which can be sealed with a rubber band, zip(as in a ziplock type bag) or something with a top. The idea is to keep the Deoxit from evaporating so it remains concentrated and wet so it can do its thing. Otherwise, I've read of people sticking stuff in alcohol or some other solvent for however long to clean things up. Probably a good idea to take care if using large amounts of anything flammable.

[Enzo]

I use a fiberglass brush eraser. I bet an "ink eraser" would work. Also FIne grit sand paper or emery paper should work. Strip the wire, lay the exposed conductor on the benchtop, and sand the stuff off, stroking only one way - towards the end of the wire. Turn the wire every few strokes to get all sides of the strands. The strands wil spread out on the bench as you stroke.

[JJGross]

Thanks guys.
Since the wires are so small and even stripping back quite a bit of insulation still showed the exact same stuff, I just replaced the wires entirely rather than mess with it anymore than I already did. This isn't a vintage device by a long shot so all I wanted was for it to work - and it now does.

Cheers,
- JJ

[Sweetfinger]

I'll use the 'Enzo' method with a small chunk of green kitchen scrubber saturated with deoxit, or alchohol. I just fold the scrubbie over the wire and pull it off the end of the wire a few times.

[JJGross]

The problem with these wires I've found was that even if I cleaned the ends of the wire, as soon as I heated it to tin it, more of this oily crap would bubble out from UNDER the insulation. It's like the strands were coated in grease, then covered in the insulation cover. Cleaning worked ... until you got it hot and more goop boiled out onto the wire. I've never seen anything like it before. Dirty wires yeah everything we fix has dirty wires, but not like this stuff. That's probably why every wire in this thing has a crimp connector on it, then the crimp connectors were the only parts soldered to the boards (there are 3 of them in this thing). Ironic that they might have used this goopy stuff to prevent corrosion, yet every wire end is corroded like nobody's business - or at least was until I got my hands on it.

That's why I just yanked out all the wires & crimps and replaced them with just plain WIRE. Less work in the long run than screwing around with that bubbly goop boiling out from under insulation every time I tried to tin a (thoroughly cleaned) strand.

Cheers,
- JJ

[Paleo Pete]

I've run across very similar wire before, sometimes a small toothbrush size brass wire brush will help, then get out my jar of paste flux and flux it till it pukes, and still have trouble getting it to take solder. Found out one of my guitar cables was in that condition one night with 15 minutes to go onstage...managed to solder the jack on, made the night, then that cable and I parted company...

I've wondered what that is, I thought maybe it was only the first foot or so and I might get a short patch cord or two out of the middle. Nope, all 15 feet or so was black coated wire that would eventually take solder, but I had to heat it until the insulation was getting soft and gooey. After a couple of tries I threw the whole thing away.

[Le Basseur]

Assuming that we're talkong copper here (and not aluminium,zinc alloy or something else),I suggest using...an aspirin pill!
(...no,you don't have to drink it,not this time! )
On a piece of something that can be thrown away after the wire cleaning,put the aspirin and above it the wire and heat the wire with your soldering gun,using a little solder as you go.Remember the old-fashion way of cleaning wires with colophonium?It's the same thing except that aspirin is much more effective/corrosive.
There are two drawbacks:the melted aspirin tends to impregnate everything underneath (that's why you shouldn't do this on the dining table-remember WAF!) and,worst,the fumes eliminated during the process are VERY unpleasant (and maybe toxic),so keep your nose on fair distance and work in well-ventilated rooms.
Regards,

[petemoore]

Not really recommended for wires conducting heat to say actives...
cut the crud off as much as you can with..fingernail sand-file, file, something that leaves a scratchy surface, I like to use a cleaned fingerprint to knock the sand off before soldering, or clean rag?..
Oil can get on there, clean soldering tip, remove insulation [can exude oily stuff]. All that..you probably already knew.
some wires and especially some jack lugs, are just plain solder-resistant.
Try anything else that makes sense, I certainly don't recommend cold solders for anything [esp HV though]...bake whatever junk is on there off there, for a while at high heat, then apply some solder to the wire....caveat...overheated copper resists solder too, so only [not really] recommended if it works [akk]..don't burn actives up trying it.
I've used the 'tacked on crap joint' method, getting another piece of
solder-taking solid core wire, shaping it as possible around the crapwire and ~hard-crimping it, then getting the solder to flow through that, hoping a tack takes in there somewhere...