Why is it almost impossible to solder this wire

[akis]

I have this wire (in many colours) http://www.farnell.com/datasheets/1581908.pdf

Solder simply runs off it and even when you think you have made a joint, it soon comes loose. You can make joints by mechanical friction, ie a blob of solder completely surrounding the wire and holding it in place, but soon the wire comes loose. Compared to any other wire this is on its own league, extremely similar to enamelled.

Any ideas why it is so difficult to solder on it?

[tautech]

Are you using a flux cored solder?

[Wh1sper]

Is it NOS?
Because after 10th of years the tin can become inactive.
Colophony helps.
Or fine sandpaper

[grumpydoc]

It's tinned copper wire so oxide on the tin would be a posibility if it is old stock (as has been suggested)

Make sure the wire is clean an that you have enough heat and flux to make a good joint

[akis]

it is tinned copper and in that it should not differ from the leads found on resistors capacitors etc all of which may have been years in my drawers, blackened and dirty and yet solder at the first touch of the iron, but this wire being new and shiny like a mirror, solidly refuses to solder unless I file it or apply a lot of extra flux and even then it is dodgy. I can pick the oldest and dirtiest resistor and I can solder it much easier than this wire, which I have just removed the insulation and it's clean.

There must be another explanation. maybe it is too shiny.

[London Lad]

What iron are you using, is it hot enough? It's a solid single core and relatively thick.

I'm in the UK, pop 6" in the post to me if you like and I'll soon tell you what's going on with it.

[dexters_lab]

i seem to find a hot iron and flux helps a lot when soldering troublesome wire like 30+ year old car loom wiring

if you have a large tip on your iron you can also get a blob hanging from the tip which you can pass the wire completely into, it's a bit messy but once it's properly tinned you can resort to normal soldering

[mamalala]

Besides all the good suggestions so far, have you checked if it _really_ is copper? This may be a far stretch, but after all there are cheap sources that sell cables where the conductors are made of iron or steel, or even aluminium. Especially the aluminium stuff is then coated with a thin copper layer, they call that crap "CCA" for Copper Clad Aluminium.

It wouldn't be the first time that some company sourced stuff from external suppliers and then didn't really get what they expected, while not really checking what they got either.

Greetings,

Chris

[Richard Crowley]

The data sheet claims: "Solid Tinned Annealed Copper Wire, PVC Insulation" But it is also "ROHS Compliant" which means it has some dodgy "tin-like"plating and may require higher heat and/or weird flux, etc. It could also be simply a bad batch that was plated with the wrong alloy that is impervious to solder unless you break through to the real copper conductor.

[Scrts]

There's a really old method: take one tablet of Aspirin, put the wire on it and apply some heat with your soldering tool. It will smell badly, but that should remove the oxide. Use at least 280-300deg temperature, because of RoHS when solering later on. Don't forget to use some soldering flux.

[jlmoon]

My suggestion: To avoid unknown trouble or issues with the device this wire is being used in, throw all of that wire out and replace with new current date coded wire as per your specifications.  The time and energy spent trying to figure out the failures in the future are not worth it   

[Richard Crowley]

I agree with jlmoon.  Just throw it out.  Or, better yet, return it to the dealer and report it as defective.  Who knows what undesirable (or potentially even life-threatening) outcome could be prevented by removing this batch from the market.

[akis]

I have 4 *  100 metre rolls of it, different colours. I will call Farnell where it came from and complain.