How to solder very thin stranded wire?

[DaveC]

This is one conductor in a cable from some iPod earphones:

http://www.tinyuploads.com/images/mizPu4.jpg

What is the best way to deal with the fibre strands and to tin the wire?

Thanks,
Dave

 

[N_Cook]

This is one conductor in a cable from some iPod earphones:

http://www.tinyuploads.com/images/mizPu4.jpg

What is the best way to deal with the fibre strands and to tin the wire?

Thanks,
Dave

Wire-wrap was considered an adequate technique for a decade.
2 pieces of very fine stripped wire, lay alongside each one , ends laying
together, a microdot of hotmelt glue on the ends and then when cool gives
something to twist between fingers, then coat with more hotmelt as
insulation. No actual soldering

 

[DaveC]

Plan A: Find a short length of very fine uninsulated wire. A single

strand from some stranded wire is what I use. Wrap it around the
insulation about 2 times, and then continue wrapping around the tinsel
wire. Clip off the excess at the end. Solder the wrapped wire to the
replacement connector.

Sounds good.

Plan B: Buy a new iPod earphone. They're cheaper than the replacment
connector.

Not using it as earbuds. Just re-purposing the cord for a corded
single-earphone-with-mic unit. Have both, and am an avid "not to the landfill
will you go" kind of guy...

And beside, I'll learn something new (ie, soldering tinsel wire).

Dave

 

[DaveC]

Wire-wrap was considered an adequate technique for a decade.

2 pieces of very fine stripped wire, lay alongside each one , ends laying
together, a microdot of hotmelt glue on the ends and then when cool gives
something to twist between fingers, then coat with more hotmelt as
insulation. No actual soldering

Very interesting.

But how does this apply to my particular need?

Dave

 

[George Herold]

This is one conductor in a cable from some iPod earphones:

http://www.tinyuploads.com/images/mizPu4.jpg

What is the best way to deal with the fibre strands and to tin the wire?

Thanks,
Dave

I did something like that... I just teased the wire away from the
fibers, cut the fibers, and the enamel on the wire burned off from the
heat of the soldering iron.

George H.

 

[mike]

Plan A: Find a short length of very fine uninsulated wire. A single
strand from some stranded wire is what I use. Wrap it around the
insulation about 2 times, and then continue wrapping around the tinsel
wire. Clip off the excess at the end. Solder the wrapped wire to the
replacement connector.

Plan B: Buy a new iPod earphone. They're cheaper than the replacment
connector.

You can tin the wire in a solder pot...or blob of solder on the end of
an iron.
Problem is that it will break almost instantly at the transition point from
stiff to flexible.

The technique mentioned above seems to be an excellent solution to that
problem.

 

[notme]

Plan A: Find a short length of very fine uninsulated wire. A single

Problem is that it will break almost instantly at the transition point from
stiff to flexible.

The technique mentioned above seems to be an excellent solution to that
problem.
Mike

I don't understand the technique.

The wire is enameled (insulated). Do I prepare the wire by burning (or
sanding) off some of the enamel first?

I start wrapping back a way and wrap toward the end of the wire?

Then I solder not the tinsel wire but only the wrapping wire beyond the end
of the tinsel wire? This looks like there is no actual soldering of the
tinsel at all (which is intentional, I presume, to avoid stress points).

 

[DaveC]

Then I solder not the tinsel wire but only the wrapping wire beyond the end

of the tinsel wire? This looks like there is no actual soldering of the
tinsel at all (which is intentional, I presume, to avoid stress points).

No, I think the wrapping wire creates a strain relief for a way back from the
point where you solder both the wrapping wire, the tinsel wires, and the
mating wire.

I think...

 

[micky]

Sounds good.


Not using it as earbuds. Just re-purposing the cord for a corded
single-earphone-with-mic unit. Have both, and am an avid "not to the landfill
will you go" kind of guy...

And beside, I'll learn something new (ie, soldering tinsel wire).

My kind of guy/

 

[micky]

I did something like that... I just teased the wire away from the
fibers, cut the fibers, and the enamel on the wire burned off from the
heat of the soldering iron.

Yes, even before I r ead your post, I remembed reading that enamel
insulation burned off during soldering. I've never relied on that,
but I guess I should have, since trying to scrape off the insulation
is enough to break the metal fibers.

 

[micky]

Another problem with very fine wire is that it dissolves in solder.

Is this for the same reason solder tips dissolve in solder (slowly).

I only use resin core, never acid core, and still the tips disappear
after years. I wouldn't mind except I had trouble finding new
screw-on tips a few years ago, because in the hobbyist-priced irons
they've gone back to screw-in tips.

 

[Spehro Pefhany]

From the graph, it appears that pure tin is the worst, with 60/40
being a close second. However, if there's any copper in the solder,
the copper wire doesn't want to dissolve. I'm not sure what's in the
RoHS solder on my bench. The label fell off long ago. I'll find some
more that doesn't have copper in it and see what happens.

I'll see if I can find some finer wire and try again. I want to see
the wire "disappear".

The cheap lead-free stuff I have has 0.7% Cu.


Best regards,
Spehro Pefhany

 

[Jamie]

Thanks. That makes sense, but I'm still skeptical. So, I tried it
again, this time with a thicker #28 bare copper wire on both my 750F
lead-tin (60/40) iron tip and my 850F RoHS tip. 15 minutes of applied
heat and I get the same result as before... nothing happened (except a
well tinned piece of wire and a pile of dross).

Digging, I found:
"Properties of Alloys of Multicore.. Solder Wires"
<https://www.distrelec.cz/ishop/Datasheets/M-POFA_eng_datasheet.pdf>
Multicore Savbit Solder is produced especially to
overcome the problem of ordinary tin/lead solders
dissolving copper. It is an alloy to which a precise
amount of copper has been added so that no further
copper absorption should take place during soldering.

From the graph, it appears that pure tin is the worst, with 60/40
being a close second. However, if there's any copper in the solder,
the copper wire doesn't want to dissolve. I'm not sure what's in the
RoHS solder on my bench. The label fell off long ago. I'll find some
more that doesn't have copper in it and see what happens.

I'll see if I can find some finer wire and try again. I want to see
the wire "disappear".

Did you first dip the wire tail in acetone to clean off the fibers and
any form of coating on the wire?

After do so, you then use a small amount of flux..

It has worked for me in the past for types of fine wire bundle in fiber
fillers.

Jamie

 

[Jamie]

The cheap lead-free stuff I have has 0.7% Cu.


Best regards,
Spehro Pefhany

really, the junk I have has 5% in it and it hate it !

Jamie