How solder to very fine enamelled woven wires in earphone lead?

I have some Sony in-ear headphones. The lead to one earpiece has been cut through completely and I want to rejoin the two wires
(which I will call 'conductors' to avoid confusion).
The two 'conductors' inside the lead are rather thin. And what is more, each of the two 'conductors' is made up of something like a dozen smaller copper wires which are woven around some very fine threads (perhaps the threads are very fine polyester yarn). The threads run along the lead as the core of the 'conductor'.
The wires of one of these two 'conductors' looks like bare copper and is unoxidised so I can probably solder to it. But the OTHER CONDUCTOR is the PROBLEM because its fine wires are enamelled.
How can I remove this enamel coating in order to be able to solder to the fine copper wires of the 'conductor'?
Below is what I have tried.
Can you advise?
Will
----------------------------
Maybe my general technique is not delicate enough or maybe I am being too clumsy but this is what I have tried with no success:
(1) Using fine glasspaper but it seems to tear the fine wires rather than strip their enamel away. Even if the wires don't break, there is still a portion of uncleaned enamel of the inner sides of the fine wires.
(2) Using a match to burn off the enamel but this leaves a black deposit which I have to scrape away with glasspaper and I am back to the beginning.
(3) Using a gas flame always seems too fierce as it burns through the wires.
----------------- END -----------------------------
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Both wires are covered with different color enamel. You can likely apply solder directly to the wires and the heat will burn off the enamel while the flux does its job. Some enamels are designed that way.
Regards,
Boris Mohar
Got Knock? - see: Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

They might be. However, the standard way is to burn them off with something like a cigarette lighter.
--
*Bigamy is having one wife too many - monogamy is the same

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat 14 May 2005 13:51:58, Boris Mohar wrote: <

Hey man, brilliant!
I just soldered the wires and, as you rightly said, the heat of the iron removed the enamel. It worked a treat.
Thank you.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Enamel is likely present on both conductors - the 'bare' group's enamel is just not dyed with distinctive color pigments.
Tin the leads using a soldering iron tip loaded with fluxed solder, starting from the cut end, where heat transfer to the copper is facilitated by direct contact. If there are a lot of wires, a solder pot speeds things up - dip in flux, then dip in the solder pot.
Do not overheat. Better to repeat the process, with fresh solder and a clean tip, than to persist with a hot tip that has burned out of flux.
The enamel used in commercial equipment is designed for solderability. Larger bundles of litz, or wires with heavy enamel, may require that this operation be repeated to contact all internal wires in the bundle. In this case, abrading the tip to increase bare copper surface area reduces time in the soldering operation.
Use of an open flame will contaminate, weaken and oxidize the conductors, making them harder to eventually solder.
RL
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

It's more likely to be tinsel wire.
--
N


















Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat 14 May 2005 16:57:13, legg wrote: <

Yup this worked a treat for me! I never realised I could solder straight onto this stuff by letting the heat of the iron remove the enamel.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

This is known as "self fluxing enamel". Doesn't work on the old style stuff though.
--
N


















Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Just watch out with that solder - through enamel. There is a warning in the Farnell catalogue about toxic fumes (Toluene di-isocyanate or something like that). It certainly hurts the eyes and so I'd use some kind of fume extraction or at least open the window.
Will wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 21 May 2005 01:24:36 +0100, Chris Jones wrote:

Double whammy - Toluene is the stuff that gets you high when you sniff glue, and di-isocyanate is superglue, so you run the risk of gluing your nostrils shut.
Cheers! Rich

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I've done this several times. The technique used is to put the tip of the soldering iron under the wire so that it just touches it. Then apply solder and it will melt on the iron tip and surround the wire. You will see a little dimple where the wire enters the solder blob. When the laquer burns away this dimple will disappear and the solder will flow a little way along the wire. Remember you will be burning off the laquer and the plastic fibers. After tinning all the wires then they can be soldered together. BTW, I think Sony uses clear, green, and red laquer. The wire with the clear laquer will appear to be bright copper but is actually coated. This wire is the common. ERS
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

This is "tinsel wire." It really doesn't solder well, and if you do manage to solder it, it will soon break at the joint. It's usually crimped. I don't know how to strip the enamel.
John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 14 May 2005 10:06:32 -0700, John Larkin

Tinsel wire is characterized by it's flat spiral winding around the core. It is not enameled and each conductor will be insulated conventionally.
It is solderable, but requires mechanical security to prevent vibration at the SJ. A crimped contact requires the same stress relief.
The OPs wire is not tinsel wire.
RL
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Oh, don't be crabby. It's a lot of fine conductors woven around a fibrous insulating core, and it's not very solderable. So it might as well be tinsel.
So, what's the absolutely correct name for this construction?
John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 14 May 2005 21:31:18 -0700, John Larkin

In North America, cables are described by their application class, UL Style number and construction.
As the wire that interests the OP is likely of Asian design and origin, it may be described somewhat differently.
Stranding count, gauge, serving style, core and jacket material would likely be required to fully describe flexible cable for consumer audio applications.
It's an interesting thought, though; just what off-beat permutations and combinations of events would be required for a Japanese manufacturer to label something with a North-American colloquialism associated with decorating material or dressmaking. Metalic threads were not unknown in centuries past, so they'd likely have their own terms for round or flattened varieties.
Last 'tinsel' wire I saw was in mono earplug leads, a la 1965. Biggest problem was normal conductor surface contamination from outgassing insulation, with age, and the further contaminating effects of burning core material at soldering temperatures.
RL
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'm at a los as to why you're posting this to a component newsgroup; it should only be in sci.electronics.repair. But anyway, each of the enameled wires is a separate conductor, and should be separate from one another. Like green might be left, and red right. And the other bare wires are the common or ground.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
My experience with Sony headphones was as above G=left, Red=Right & Copper=Common. Sometimes they're actually all wound together, you just need to tease the colors out. I've usually tinned them using a gun. Also check the cord down aways as there is probably damage further along. All the tinsel cord I've seen used crimp connections or mechanicaly attached plugs. That goes back to the '50s and my crystal radio set. My stepdaughter dances around her room with her headphones on. I've repaired the cord ~ 10 times. Richard
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Same here in the Atari 2600 and Super Mario Bros years back in the '70s, when a neighbor bought one for his kids. I must've repaired the joystick at least a half dozen times.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

My kids were just hitting their teens when the Atari 2600 came along. We bought one, and it was almost never turned off... After two power supplies burned out, I built a supply robust enough to last. The joysticks and the switches on the main unit were all rebuilt *many* times. That Atari finally just got too hard to maintain, and we bought another one and, except for the power supply problem, started the whole sequence again.
It was fascinating to watch the kids learn to fix those things. Initially I had to work on it, but it wasn't long before they did all the repair work.
Another fun thing about that Atari was the process that we went through with every new game. I could understand the instructions better, so I'd win at most of the games... for about the first half a dozen iterations. That's when the kids would catch up in understanding what the point of the game was. Then their reflexes took over, and by the time they had the experience of maybe 10 or 12 games, there was simply no point in me even attempting to play against them.
--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson
Ukpeagvik (Barrow, Alaska) snipped-for-privacy@barrow.com
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

It's easier and better to just replace the entire headphone cable. Get oneoff a pair of cheapo headphones.(I get them for a buck at my local dollar tree and just desolder the leads at the transducers.) As for removing the varnish insulation you canuse a standard exacto knife and gently scrape it away or a clean solder tip to burn it off. Resolder the leads to the Sony transducer elements using a 20-30 watt soldering pencil, any higher will just melt half the project.(You can also use a hemostat clamped on the downside of the wire to act as a heatsink to keep from melting any of the lead.) Helps to use a good brand of flux and solder.(I use a high silver content solder, not the 60/40 tin/lead stuff.)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.