Jumper wire

[Kerkana]

Hello, I wanted to know are jumper wires like this for example

Supposed to make contact once soldered?

I have to be sure that the end of the wire falls on the weld to have continuity, however it is indicated that by heating the cover melts

[Kim Christensen]

It's mislabeled. That is called magnet wire. Used for winding coils, transformers, motors, etc. It has a very thin polymer film on it that must be scraped off or chemically removed before soldering.
What you want is insulated buss wire, or just the right gauge of stranded wire, depending on what you want to use it for.

[Gyro]

It sounds like the stuff that is / was used in wiring pencils in the UK (search 'Roadrunner wiring pencil'). If it's the same stuff, then it is Polyurethane insulated wire with insulation that melts (burns off) under soldering heat.

I used to use it at work for prototyping many years ago. Note that it is a smelly operation, needs a high tip temperature to work properly and (I think) gives off Cyanide fumes, among others, during soldering. You need a well ventilated space. Not recommended.

[Kerkana]

Thanks for your help, it looks like it.

I solder at 320°C with lead solder, and maybe that's not enough to melt the layer

It's used to make bridges when tracks no longer make contact, it says enameled/non enameled I don't know the difference

[Gyro]

No, irrc it required 400'C+. One of my collegues had his iron set so that it glowed very dull red in the dark - I'm not sure off-hand what temperature that would have been!

[barshatriplee]

Here is also a good article about best wire for breadboard: https://www.allaboutcircuits.com/news/the-best-wire-for-breadboarding/

[Kim Christensen]

The idea of melting insulation while trying to solder sounds like a bad idea to me. It just contaminates the joint and makes a mess. That's the whole point of using flux on relatively clean copper: To clean off the minute amount of oxide to ensure a good bond. Adding a bunch of melting/burning plastic is just dumb.

[mwb1100]

it says enameled/non enameled I don't know the difference

It should say only one or the other (since it can't be both enameled and not enameled).  If the wire is enameled it should be sanded to remove the enamel before soldering.

[langwadt]

The idea of melting insulation while trying to solder sounds like a bad idea to me. It just contaminates the joint and makes a mess. That's the whole point of using flux on relatively clean copper: To clean off the minute amount of oxide to ensure a good bond. Adding a bunch of melting/burning plastic is just dumb.

you cut to length and dip the end in a blob of solder on the soldering iron, is fantastic for bodge wires

[tooki]

Here is also a good article about best wire for breadboard: https://www.allaboutcircuits.com/news/the-best-wire-for-breadboarding/

This thread clearly isn’t about breadboard jumpers.

[Haenk]

AFAIR there are/were scraping tools for this kind of laquered wire, essentially two blades mounted on some kind of pliers. Certainly way better than burning off the laquer.
I would use this as patch cable for PCB repairs with only limited space available, for normal use, there are better options.

[Berni]

Yep this is "magnet wire"

It indeed needs a soldering iron set to 400°C or more to melt away the thin coating of insulation. This works well for making bodge wires on PCBs since it is commonly available in very thin diameters and the insulation coating takes up almost no space, so you can solder it onto tiny components like 0402 passives or 0.4mm pitch chips nicely. It also blends into the PCB pretty well, making the bodge less visible.

Some flux also helps eat away the insulation, so i will usually tin the end of it on a hot soldering iron by adding some solder to it. There is so little insulation material that it doesn't really make any mess.  Scraping it off on such thin wire is way too fiddly and time consuming. It is designed to be simply soldered at high heat, that's how tiny transformers, relay coils etc... are terminated, first wrapped around a post then soldered.

Tho personalty i tend to use Kynar/PVDF wire for this. The wire i got is also often tin or silver plated, making it easy to solder without tinning. The insulation is a bit bulkier, but has a nice property of shrinking slightly when exposed to soldering iron heat, yet not melting. So you can just cut it to length then press the soldering iron against the end to make the insulation shrink away and expose about half a milimeter of wire for you to solder onto a IC pin.

If you want jumper wires for breadboard use, just cut up a solid wire CAT5 ethernet cable. Those are the perfect size for breadboards and you get lots of colors.