Making connection to very fine wire?...

B

Bob Engelhardt

Guest
I have a length of wire that\'s from an ear-pod. The outer diameter is
only about 1mm and there are 2 conductors, each consisting of 8 strands
of very fine filaments twisted together:

https://imgur.com/a/ybBRxHQ (the scale is mm\'s)

Each filament is insulated with a varnish. How can I make a connection
to these conductors? Strip the varnish & solder, or can a crimp
connection be made through it? If strip, how to? Is it not copper &
not solder-able? Or is it not even practical to re-use this wire at
all? So many questions, but I hope that I can save a LOT of trial &
error if somebody has experience with this.

BTW - I want to use this for its size & flexibility, to attach an LED to
be fed into small spaces for illumination.

Thanks, Bob
 
Bob Engelhardt <BobEngelhardt@comcast.net> wrote:

... How can I make a connection
to these conductors? Strip the varnish & solder, or can a crimp
connection be made through it?
Click to expand...

My experience with trying to connect enamel-coated wire (much thicker
gauge than yours) to a \'chocolate block\' terminal was that the screw cut
through the copper before it punctured the enamel. I doubt if you could
expect much success with a crimp terminal. Modern self-fluxing varnish
usually breaks down if you can get it, and the wire end, up to soldering
temperature.

In the past I have connected fine wires made of \'unsolderable\' material
using a \'Mitcham tagstrip\', (so called because Philips and Mullard
radios used them). Wind about 6 turns of thin tinned copper wire around
the shank of a small drill bit, then thread the unsolderable wire
through it and fill it with solder. This usually results in a
connection, especially if you scrape the wire a bit while it is
surrounded by molten solder.

If that is a bit too big for your purposes, you could try something
similar by lacing the wire through a solder blob on a small piece of
perforated Veroboard.

Good Luck.

--
~ Liz Tuddenham ~
(Remove the \".invalid\"s and add \".co.uk\" to reply)
www.poppyrecords.co.uk
 
On Saturday, November 27, 2021 at 8:58:40 AM UTC-5, bobenge...@gmail.com wrote:
I have a length of wire that\'s from an ear-pod. The outer diameter is
only about 1mm and there are 2 conductors, each consisting of 8 strands
of very fine filaments twisted together:

https://imgur.com/a/ybBRxHQ (the scale is mm\'s)

Each filament is insulated with a varnish. How can I make a connection
to these conductors? Strip the varnish & solder, or can a crimp
connection be made through it? If strip, how to? Is it not copper &
not solder-able? Or is it not even practical to re-use this wire at
all? So many questions, but I hope that I can save a LOT of trial &
error if somebody has experience with this.

BTW - I want to use this for its size & flexibility, to attach an LED to
be fed into small spaces for illumination.

Thanks, Bob
Click to expand...

Some sort of chemical etch to remove the enamel would be ideal but I don\'t know of any. Maybe some experienced ppl that have done this and that hang out here can be of help.
What has worked for me is to use some extremely fine sandpaper, e.g. >500 grit and gently drag it across the strands. It is a delicate balance of using enough force to mechanically remove the enamel and not stress/break the strands. I\'ve also use a exacto/modeling knife to scrape away the enamel but not nicking the wire to the point of breaking it is tricky. A magnifying glass comes in hands for this kind of work.

You can then use flux to help remove remaining impurities & enamel when soldering. Wrapping the strands around a thicker piece of copper conductor, tie in place with a piece of copper wire to secure it may be helpful.
There is also a technique where thin solder is wrapped around the joint, heat the wires and at some point the solder will melt.

I don\'t know of any crimp that would work in this situation as they use mechanical force to make a connection. With this fine a wire, I don\'t think it would hold up.
Good luck
J
 
In article <gQqoJ.126330$IW4.67570@fx48.iad>, BobEngelhardt@comcast.net
says...
Each filament is insulated with a varnish. How can I make a connection
to these conductors? Strip the varnish & solder, or can a crimp
connection be made through it? If strip, how to? Is it not copper &
not solder-able? Or is it not even practical to re-use this wire at
all? So many questions, but I hope that I can save a LOT of trial &
error if somebody has experience with this.

BTW - I want to use this for its size & flexibility, to attach an LED to
be fed into small spaces for illumination.
Click to expand...

Depending on the varnish there are several ways to get it off not
counting the scrapeing . Some will burn the varnish off with the heat
of the soldering iron. On others I have taken a butane lighter and
burnt off the insulation then clean off the burnt part.
 
Depending on the varnish there are several ways to get it off not
counting the scrapeing . Some will burn the varnish off with the heat
of the soldering iron. On others I have taken a butane lighter and
burnt off the insulation then clean off the burnt part.
Click to expand...

Most varnish will break down at soldering temperature. To get up to temp work against a firm insulating surface ( newspaper) (rather than working in mid-air) so you get good pressure and heat transfer. Tin the wires the same way. having extra flux to brush on may help.
 
On 11/27/2021 11:03 AM, Liz Tuddenham wrote:
My experience with trying to connect enamel-coated wire (much thicker
gauge than yours) to a \'chocolate block\' terminal was that the screw cut
through the copper before it punctured the enamel. ...
Click to expand...

That saves me some time & frustration of trying it myself, thanks.

In the past I have connected fine wires made of \'unsolderable\' material
using a \'Mitcham tagstrip\', (so called because Philips and Mullard
radios used them). Wind about 6 turns of thin tinned copper wire around
the shank of a small drill bit, then thread the unsolderable wire
through it and fill it with solder. This usually results in a
connection, especially if you scrape the wire a bit while it is
surrounded by molten solder.
Click to expand...

Great idea. Even if the strands are solderable, this could be a good
way to manage such small strands.
If that is a bit too big for your purposes, you could try something
similar by lacing the wire through a solder blob on a small piece of
perforated Veroboard.
Click to expand...

Maybe as the last resort :)
 
On 11/27/2021 12:12 PM, Three Jeeps wrote:
> Some sort of chemical etch to remove the enamel would be ideal but I don\'t know of any. ...

I have a bottle of methylene chloride (the stuff good paint strippers
used to be made with) - it would be worth a try.

> What has worked for me is to use some extremely fine sandpaper, e.g. >500 grit and gently drag it across the strands. It is a delicate balance of using enough force to mechanically remove the enamel and not stress/break the strands. I\'ve also use a exacto/modeling knife to scrape away the enamel but not nicking the wire to the point of breaking it is tricky. A magnifying glass comes in hands for this kind of work.

\"it is tricky\" indeed - I have had the frustration of trying. I might
come to being desperate enough to do it again.

....
> There is also a technique where thin solder is wrapped around the joint, heat the wires and at some point the solder will melt.

That would be a good way to keep all those tiny strands in place

> I don\'t know of any crimp that would work in this situation as they use mechanical force to make a connection. With this fine a wire, I don\'t think it would hold up.

I agree

Thanks for the help
 
On 11/27/2021 12:23 PM, Ralph Mowery wrote:
Depending on the varnish there are several ways to get it off not
counting the scrapeing . Some will burn the varnish off with the heat
of the soldering iron. On others I have taken a butane lighter and
burnt off the insulation then clean off the burnt part.
Click to expand...

I\'ll try the soldering iron. I suspect that any flame might destroy the
copper along with the varnish - it is really thin. Either way, the
burnt residue would have to be dealt with. RA flux might do it.

Thanks
 
On 11/27/2021 3:06 PM, malua mada! wrote:
Depending on the varnish there are several ways to get it off not
counting the scrapeing . Some will burn the varnish off with the heat
of the soldering iron. On others I have taken a butane lighter and
burnt off the insulation then clean off the burnt part.

Most varnish will break down at soldering temperature. To get up to temp work against a firm insulating surface ( newspaper) (rather than working in mid-air) so you get good pressure and heat transfer. Tin the wires the same way. having extra flux to brush on may help.
Click to expand...

Heat is beginning to sound like the best approach, thanks.
 
Bob Engelhardt <BobEngelhardt@comcast.net> wrote:
I have a length of wire that\'s from an ear-pod. The outer diameter is
only about 1mm and there are 2 conductors, each consisting of 8 strands
of very fine filaments twisted together:

https://imgur.com/a/ybBRxHQ (the scale is mm\'s)

Each filament is insulated with a varnish. How can I make a connection
to these conductors? Strip the varnish & solder, or can a crimp
connection be made through it? If strip, how to? Is it not copper &
not solder-able? Or is it not even practical to re-use this wire at
all? So many questions, but I hope that I can save a LOT of trial &
error if somebody has experience with this.

BTW - I want to use this for its size & flexibility, to attach an LED to
be fed into small spaces for illumination.

Thanks, Bob
Click to expand...

With earphone cables it has been my experience that you can simply
solder the wires without stripping them. The coating seems to
vanish under the solder flux.
 
On Sun, 28 Nov 2021 09:55:34 -0500, Bob Engelhardt
<BobEngelhardt@comcast.net> wrote:

On 11/27/2021 12:12 PM, Three Jeeps wrote:
Some sort of chemical etch to remove the enamel would be ideal but I don\'t know of any. ...

I have a bottle of methylene chloride (the stuff good paint strippers
used to be made with) - it would be worth a try.

What has worked for me is to use some extremely fine sandpaper, e.g. >500 grit and gently drag it across the strands. It is a delicate balance of using enough force to mechanically remove the enamel and not stress/break the strands. I\'ve also use a exacto/modeling knife to scrape away the enamel but not nicking the wire to the point of breaking it is tricky. A magnifying glass comes in hands for this kind of work.

\"it is tricky\" indeed - I have had the frustration of trying. I might
come to being desperate enough to do it again.

...
There is also a technique where thin solder is wrapped around the joint, heat the wires and at some point the solder will melt.

That would be a good way to keep all those tiny strands in place

I don\'t know of any crimp that would work in this situation as they use mechanical force to make a connection. With this fine a wire, I don\'t think it would hold up.

I agree

Thanks for the help
Click to expand...
Methylene chloride is what we used as a stripper when we soldered ends
on Monster rca cables.
 
On 11/28/2021 11:09 AM, root wrote:
With earphone cables it has been my experience that you can simply
solder the wires without stripping them. The coating seems to
vanish under the solder flux.
Click to expand...

We have a winner.

Trying the simplest first, I used a soldering iron to burn off the
varnish. And threw on some solder to conduct the heat better. To my
great surprise, the solder stuck. Worried that maybe it looked good,
but was just sticking, without making good contact, I checked the
resistance. 0.7R with a so-so DMM. That\'s over 4 feet of conductor.
Good enough for me.

https://imgur.com/pmAyafu
 
In article <MPG.3c0c338eb52d0d5e989b75@news.eternal-september.org>,
rmowery42@charter.net says...
In article <gQqoJ.126330$IW4.67570@fx48.iad>, BobEngelhardt@comcast.net
says...

Each filament is insulated with a varnish. How can I make a connection
to these conductors? Strip the varnish & solder, or can a crimp
connection be made through it? If strip, how to? Is it not copper &
not solder-able? Or is it not even practical to re-use this wire at
all? So many questions, but I hope that I can save a LOT of trial &
error if somebody has experience with this.

BTW - I want to use this for its size & flexibility, to attach an LED to
be fed into small spaces for illumination.




Depending on the varnish there are several ways to get it off not
counting the scrapeing . Some will burn the varnish off with the heat
of the soldering iron. On others I have taken a butane lighter and
burnt off the insulation then clean off the burnt part.
Click to expand...

Decades ago I recall a varnish that was specificaally formulated to
become a flux when soldering. So I am sure it is possible, but whether
that is what you have got is a different matter!
 
Mike Coon <gravity@mjcoon.plus.com> wrote:

In article <MPG.3c0c338eb52d0d5e989b75@news.eternal-september.org>,
rmowery42@charter.net says...

In article <gQqoJ.126330$IW4.67570@fx48.iad>, BobEngelhardt@comcast.net
says...

Each filament is insulated with a varnish. How can I make a connection
to these conductors? Strip the varnish & solder, or can a crimp
connection be made through it? If strip, how to? Is it not copper &
not solder-able? Or is it not even practical to re-use this wire at
all? So many questions, but I hope that I can save a LOT of trial &
error if somebody has experience with this.

BTW - I want to use this for its size & flexibility, to attach an LED to
be fed into small spaces for illumination.




Depending on the varnish there are several ways to get it off not
counting the scrapeing . Some will burn the varnish off with the heat
of the soldering iron. On others I have taken a butane lighter and
burnt off the insulation then clean off the burnt part.

Decades ago I recall a varnish that was specificaally formulated to
become a flux when soldering. So I am sure it is possible, but whether
that is what you have got is a different matter!
Click to expand...

It\'s very common nowadays, so the chances are that these wires will be
insulated with it.


--
~ Liz Tuddenham ~
(Remove the \".invalid\"s and add \".co.uk\" to reply)
www.poppyrecords.co.uk
 
On Sun, 28 Nov 2021 12:37:40 -0500, Bob Engelhardt
<BobEngelhardt@comcast.net> wrote:

We have a winner.

Trying the simplest first, I used a soldering iron to burn off the
varnish. And threw on some solder to conduct the heat better. To my
great surprise, the solder stuck. Worried that maybe it looked good,
but was just sticking, without making good contact, I checked the
resistance. 0.7R with a so-so DMM. That\'s over 4 feet of conductor.
Good enough for me.

https://imgur.com/pmAyafu
Click to expand...

Back in the stone age, when telephone coil cord wiring was made of
\"tinsel\" (copper foil), we had a similar problem. I would strip off
any insulation from the tinsel wires with either furniture stripper,
desoldering braid or Xacto knife. However, instead of soldering
directly to the tinsel, I would find the smallest diameter uninsulated
wire strand and wrap the tinsel with the fine wire. To give it more
strength, I would continue wrapping around any remaining insulation.
After wrapping, apply solder. From the photo, you might need to
remove some of the solder you added.


--
Jeff Liebermann jeffl@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
 
Bob Engelhardt <BobEngelhardt@comcast.net> wrote:

I have a length of wire that\'s from an ear-pod. The outer diameter is
only about 1mm and there are 2 conductors, each consisting of 8 strands
of very fine filaments twisted together:

https://imgur.com/a/ybBRxHQ (the scale is mm\'s)

Each filament is insulated with a varnish. How can I make a connection
to these conductors? Strip the varnish & solder, or can a crimp
connection be made through it? If strip, how to? Is it not copper &
not solder-able? Or is it not even practical to re-use this wire at
all? So many questions, but I hope that I can save a LOT of trial &
error if somebody has experience with this.
Click to expand...

There is a further hazard which nobody has mentioned yet: if the wires
are very fine (48swg or higher) and they are made of copper, they will
dissolve in ordinary solder. The way to overcome this is to use a
solder that is already saturated with copper, such as \"Savbit\".

It rarely causes a problem with normal work, but becomes significant in
the repair of moving coil meters and similar fine work.


--
~ Liz Tuddenham ~
(Remove the \".invalid\"s and add \".co.uk\" to reply)
www.poppyrecords.co.uk
 
On 11/28/2021 4:13 PM, Mike Coon wrote:
Decades ago I recall a varnish that was specificaally formulated to
become a flux when soldering. So I am sure it is possible, but whether
that is what you have got is a different matter!
Click to expand...

I probably do have it, given the ease with which I was able to get
solder to stick. What a great idea - I hope the company that invented
it made a lot of money from it.
 
On 11/29/2021 5:34 AM, Liz Tuddenham wrote:
There is a further hazard which nobody has mentioned yet: if the wires
are very fine (48swg or higher) and they are made of copper, they will
dissolve in ordinary solder. The way to overcome this is to use a
solder that is already saturated with copper, such as \"Savbit\".

It rarely causes a problem with normal work, but becomes significant in
the repair of moving coil meters and similar fine work.
Click to expand...

I didn\'t measure the strands, but 8 of them twisted together made a
0.01\" diameter conductor. Pretty fine. Time will tell, but with any
luck I\'ll be dead before it\'s a problem.

Thanks
 
Bob Engelhardt <BobEngelhardt@comcast.net> wrote:

On 11/29/2021 5:34 AM, Liz Tuddenham wrote:
There is a further hazard which nobody has mentioned yet: if the wires
are very fine (48swg or higher) and they are made of copper, they will
dissolve in ordinary solder. The way to overcome this is to use a
solder that is already saturated with copper, such as \"Savbit\".

It rarely causes a problem with normal work, but becomes significant in
the repair of moving coil meters and similar fine work.

I didn\'t measure the strands, but 8 of them twisted together made a
0.01\" diameter conductor. Pretty fine. Time will tell, but with any
luck I\'ll be dead before it\'s a problem.
Click to expand...

I really hope I have misunderstood your reply: the copper dissolves
during soldering, not afterwards; so unless you are doing something
remarkably careless, you should still be alive at the end of it.

:)

--
~ Liz Tuddenham ~
(Remove the \".invalid\"s and add \".co.uk\" to reply)
www.poppyrecords.co.uk
 
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