Need help soldering copper wire for LED cube project

Other Hardware General Electronics
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Hi, I’m a beginner working on my first electronics project – a 4x4x4 LED cube using an Arduino Nano. For the frame, I picked 14 AWG single-core copper wire.

My issue is that the solder just won’t stick to the copper wire. I tried sanding off the coating with sandpaper, and I’ve also tried both tin-lead solder and lead-free rosin core solder, but still no luck.

Did I pick the wrong wire size? Or am I doing something wrong with the soldering process? Any advice or beginner tips would really help me out. Thanks!

2

What coating? Copper wire should solder easily. Please post a link to the wire you are using.

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Use real lead solder with rosin core BUT I would also apply liquid flux, I use it all the time and my soldering goes quickly. Make sure the temp of your soldering iron is hot enough for the solder. I use 350C/700F. I use about 60/40 Sn/Pb

5

That page says

Ideal for electric application

I think you could ask for a refund because not taking solder is definitely not ideal for electric application!

I think it may be enameled. Sanding off the enamel should allow easy soldering, if you truly have sanded off all the enamel.

I think you will know when you have sanded off all the enamel when it will take solder.

Another possibility: could this be enameled, copper-coated aluminium wire? If you sand off the enamel and the copper, the wire will look dull grey and will be difficult to solder.

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Maybe. That is prety heavy gauge wire and if you have long pieces and several pieces to join, you neet to get it very hot in order for it to take solder. A 30W-50W iron won't do.

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14AWG is 1.62814mm D. I have never seen that gauge enamelled, but I guess it's possible. If it was enamelled, then what @PaulRB said is bang on.

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If it's a simple cube, then tin the wires first where they will connect. Now wrap one wire around the other and use a butane type torch to heat the joint hot enough to take a large diameter rosin core lead solder.

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  • It might help to tin the wire lengths first, should be considerably easier once all the wire is prepared.
  • Sand paper, a 60W iron with a large tip, and liquid/paste flux will make the job easier.
10

Use solder that is at least 1mm.

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My 600 Ohm feed line which is 125 feet plus is all 14 AWG and coated with insulation, perhaps some type of nylon, no one uses enamel any more. It is perfectly good after 15 years in the weather. I had to scrape the insulation where solder was needed. That is also over 15 years old.

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Here is something I soldered using AWG 12 and AWG 18. Needed a 200W soldering gun to get it hot enough to take solder

image
image1600×1200 202 KB

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@antonydarwin

It would be helpful if you could show some photos of your project, especially your attempt at soldering.

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:face_with_spiral_eyes:

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The OP needs to buy/use only tinned wire! Leave the bare copper until more experience is gained. I discovered some tinned copper wire I had for years was actually stainless steel and would not take solder at all.

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To my knowledge, enamelled wire is for wrapping transformers. I am not aware of it being used anywhere else.

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The link shows BRASS wire, copper / zinc alloy. Never tried to solder brass...?

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Nice work!

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@antonydarwin It's doable if you are experienced, but brazing is easier.

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@antonydarwin If it is BRASS, that explains his problem. The underpowered ill prepared surface will allow the zinc to oxidize and prevent the solder from sticking.