Ethernet cable difficult / impossible to solder?

[Bucic]

Recently  I needed a crossover on the double. So I proceeded with cutting a cable  and re-soldering. Try imagining my face during the attempt I'm a  fixeverything guy, I've been soldering this and that for years, from  audio jacks to some PCB repairs even. But this... THIS! After an hour I  failed to establish a single fusing of solder with any of the wires.  Literally!  
I'm using this solder

[https://www.cynel.com.pl/en/products/117-pb60sn40-sw26](https://www.cynel.com.pl/en/products/117-pb60sn40-sw26)

It  has flux in it. I even used additional liquid flux, various  temperatures from 360 to 420. Not a single piece of solder tinned a wire.

The strands of the wires were silver in color.

 

Any thoughts? Is there something mysterious about Ethernet cables in general as far as soldering is concerned?

[okopanja]

Ethernet cables are not re-soldered, ever. Even if you succeed you will not end up with cable of high speeds.

Ethernet cables are pressed together with special tool.

If you need a longer cross over cable, either buy one finished or buy connectors, cable and something like this:

https://www.amazon.de/LogiLink-WZ0012-Netzwerk-Werkzeug-Tasche/dp/B003Y3S0U2/ref=sr_1_4?keywords=lan+kabel+zange&qid=1699783293&sr=8-4

 

Here:

 

[Johnny Dioxin]

Yes, I did this myself - bought the necessary bits from Amazon and put the connectors on myself after cutting a reel of cable to the required length. It's very easy - I made a simple picture showing the correct order of the wires (by colour) so that it was an easy reference for future jobs, too.

Much easier than it looks.

[Bucic]

I know, I know. But I'm curious what's so special about the wires. I'd accept difficulties. Hey, they might be chineesium steel or something. But for not a single drop of solder fusing... I simply must know why.

And yes, im putting a handful of Ethernet connectors in my next electronics order. A box of audio mini jacks and Ethernet connectors is a must nowadays.

[okopanja]

1 hour ago, Bucic said:

I know, I know. But I'm curious what's so special about the wires. I'd accept difficulties. Hey, they might be chineesium steel or something. But for not a single drop of solder fusing... I simply must know why.

And yes, im putting a handful of Ethernet connectors in my next electronics order. A box of audio mini jacks and Ethernet connectors is a must nowadays.

The main problem is that when you join 2 metal materials, the join is never perfect. The resistance will some somewhat higher, but worst is the forming of so called parasitic capacitance. These can interfere with the signal. Even worse when you do it with 2 different materials. And btw: soldiering is not quite bendable.

Do it properly or you will suffer from inexplicable connection losses.

[kksnowbear]

Well, I can tell you, though you might not like it much...

Solder, as you may know, is an alloy.  This is done for a lot of reasons, obviously electrical conductivity, but also to obtain a low melting point.

The specific alloy used (in your case 60:40 tin/lead) will in turn alloy with other metals (as you termed it, 'fusing', but it's very important to recognize that what's actually happening is alloying).  You're using heat to create or modify an alloy - and therein lies the problem.

An alloy means the composing metals are actually combined to create a new material; for example, solder is composed of base metals tin and lead, but the end product is neither tin nor lead.  It is a new metal which is 60% tin and 40% lead (in your case, although I would strongly recommend you consider using 63/37 - but that's a much longer conversation).

Certain metals will not alloy with certain other metals.  You can't solder stainless steel with tin/lead alloy.  The solder won't 'stick' or as you put it 'fuse'.  The metals won't alloy.

You either have to use solder intended for the metal you're attempting to solder, or use another means (usually this means mechanical connectors as discussed above).

We all know the wire used for electrical cables is copper, at least at it's core.  However, it's not uncommon that the copper wires are plated ("tinned") with another metal, for a number of reasons, like cost or corrosion resistance, etc.

Since ethernet wires are not intended to be soldered, the manufacturer of your cable has chosen to tin the individual strands of wire with a metal - probably an alloy itself - that cannot be alloyed with tin/lead alloy.

The solder and flux used for any soldering operation depends on the work:  Electronics usually 63/37 (if lead is allowed) with rosin flux, 50/50 tin/lead with acid flux if you're sweating copper plumbing.  Jewelers and other metal workers sometimes solder with what is called 'silver solder' which is yet another type of alloy.  Again, it depends on the work.

In any case, it is likely you won't find a solder composition that will alloy with those wires.  They aren't intended to be soldered, and are thus tinned/plated with a metal that cannot alloy with tin/lead alloy.

HTH

(EDIT: For reference, I was a US Navy micro-min certified avionics repair tech for 10 years.  This involved 8 weeks training for the first level, and two other four week courses just for the 'micro' cert, plus required annual recertifications.  This is not  DIY homeowner or basic electronics soldering.  It is a recognized military specialty of itself.  In fact, first thing they told us on the first day is "Forget all that sh!t you think you already know about soldering".  We then spent two days discussing metallurgy and other factors involved in soldering electronics - including alloys - before even so much as turning on an iron.)

Edited November 12, 2023 by kksnowbear

[Bucic]

1 hour ago, kksnowbear said:

Well, I can tell you, though you might not like it much...

Solder, as you may know, is an alloy.  This is done for a lot of reasons, obviously electrical conductivity, but also to obtain a low melting point.

The specific alloy used (in your case 60:40 tin/lead) will in turn alloy with other metals (as you termed it, 'fusing', but it's very important to recognize that what's actually happening is alloying).  You're using heat to create or modify an alloy - and therein lies the problem.

An alloy means the composing metals are actually combined to create a new material; for example, solder is composed of base metals tin and lead, but the end product is neither tin nor lead.  It is a new metal which is 60% tin and 40% lead (in your case, although I would strongly recommend you consider using 63/37 - but that's a much longer conversation).

Certain metals will not alloy with certain other metals.  You can't solder stainless steel with tin/lead alloy.  The solder won't 'stick' or as you put it 'fuse'.  The metals won't alloy.

You either have to use solder intended for the metal you're attempting to solder, or use another means (usually this means mechanical connectors as discussed above).

We all know the wire used for electrical cables is copper, at least at it's core.  However, it's not uncommon that the copper wires are plated ("tinned") with another metal, for a number of reasons, like cost or corrosion resistance, etc.

Since ethernet wires are not intended to be soldered, the manufacturer of your cable has chosen to tin the individual strands of wire with a metal - probably an alloy itself - that cannot be alloyed with tin/lead alloy.

The solder and flux used for any soldering operation depends on the work:  Electronics usually 63/37 (if lead is allowed) with rosin flux, 50/50 tin/lead with acid flux if you're sweating copper plumbing.  Jewelers and other metal workers sometimes solder with what is called 'silver solder' which is yet another type of alloy.  Again, it depends on the work.

In any case, it is likely you won't find a solder composition that will alloy with those wires.  They aren't intended to be soldered, and are thus tinned/plated with a metal that cannot alloy with tin/lead alloy.

HTH

(EDIT: For reference, I was a US Navy micro-min certified avionics repair tech for 10 years.  This involved 8 weeks training for the first level, and two other four week courses just for the 'micro' cert, plus required annual recertifications.  This is not  DIY homeowner or basic electronics soldering.  It is a recognized military specialty of itself.  In fact, first thing they told us on the first day is "Forget all that sh!t you think you already know about soldering".  We then spent two days discussing metallurgy and other factors involved in soldering electronics - including alloys - before even so much as turning on an iron.)

 

Wow, thank you for the comprehensive answer. In my mind the only thing composition of solder influences is the degree of ease of soldering. The total inability to solder to the slightest degree boggled my mind with that Ethernet cable!

You had an interesting career. May I ask in which direction you moved afterwards?
 

In the subject of soldering, just yesterday I also managed to crack an SMD thermistor at the bottom of my 3D printer. One day after finishing an overhaul and re-calibration It's stuck at 50kOhm and the printer thinks it's -50 deg C.

[kksnowbear]

On 11/12/2023 at 8:08 AM, Bucic said:

You had an interesting career. May I ask in which direction you moved afterwards?

Thank you, of course 

In the Navy my primary training/duty was as a flight simulator tech, but in the early 80's the Navy decided to contract that work to civilians.  We were all forced to change jobs and re-train etc. I wound up going back to electronics school for a further year (a very difficult course called "C school" in the Navy) and changed over to anti-submarine warfare tech.  Because of this, I was reassigned to Jacksonville FL to the Master Patrol Base...and because of that, when I got out 5 years later, I applied to the F/A-18 maintenance program at NAS Cecil Field and was offered an avionics position by McDonnell Douglas (the Hornet's original manufacturer; at the time Cecil Field was a Master Jet Base supporting the F/A-18).

However, between when I applied and the offer, I had already taken a job doing computerized systems maintenance with a company out of Atlanta.  I felt compelled to decline the McDonnell Douglas offer, as I'd already made a commitment to the other company.

That other company wound up being owned (two decades later) by Xerox.  I worked with them in one role or another for 26 years; my last full time position was a National Service Manager in computerized revenue control systems (not copiers lol!!)  Over that time I worked with design, installation, and maintenance of systems at over 20 of the 25 biggest international airports in the US.  These systems had 20-100+ workstations each, as well as associated backend servers, data warehousing etc.

I really liked the technical work, but career wise I needed to move into management, which I didn't care for at all, though the money was good.  I left at the end of 2016.

Since the mid-90s, I've been doing custom PC builds as a kind of part-time enterprise, and I still do 15 or 20 a year now.  I do computerized systems design and maintenance by contract, and I also do commissioned electronics assembly work (with my wife, who was actually a micro-min certifier in the Navy) for local companies, which includes through-hole and SMD components.  Here's some solder work I've done/am doing:

 

 

 

Edited November 13, 2023 by kksnowbear

[Bucic]

On 11/12/2023 at 4:24 PM, kksnowbear said:

Thank you, of course 

In the Navy my primary training/duty was as a flight simulator tech, but in the early 80's the Navy decided to contract that work to civilians.  We were all forced to change jobs and re-train etc. I wound up going back to electronics school for a further year (a very difficult course called "C school" in the Navy) and changed over to anti-submarine warfare tech.  Because of this, I was reassigned to Jacksonville FL to the Master Patrol Base...and because of that, when I got out 5 years later, I applied to the F/A-18 maintenance program at NAS Cecil Field and was offered an avionics position by McDonnell Douglas (the Hornet's original manufacturer; at the time Cecil Field was a Master Jet Base supporting the F/A-18).

However, between when I applied and the offer, I had already taken a job doing computerized systems maintenance with a company out of Atlanta.  I felt compelled to decline the McDonnell Douglas offer, as I'd already made a commitment to the other company.

That other company wound up being owned (two decades later) by Xerox.  I worked with them in one role or another for 26 years; my last full time position was a National Service Manager in computerized revenue control systems (not copiers lol!!)  Over that time I worked with design, installation, and maintenance of systems at over 20 of the 25 biggest international airports in the US.  These systems had 20-100+ workstations each, as well as associated backend servers, data warehousing etc.

I really liked the technical work, but career wise I needed to move into management, which I didn't care for at all, though the money was good.  I left at the end of 2016.

Since the mid-90s, I've been doing custom PC builds as a kind of part-time enterprise, and I still do 15 or 20 a year now.  I do computerized systems design and maintenance by contract, and I also do commissioned electronics assembly work (with my wife, who was actually a micro-min certifier in the Navy) for local companies, which includes through-hole and SMD components.  Here's some solder work I've done/am doing:

 

 

 

 

 

 

 

Holly molly! That's a huge chunk of history. Thank you for sharing. I wish you did a walkaround through all the major milestones of your career as a trip video with interviews    I'm kiiind of, little bit involved with electronics component obsolescence right now.