Enamel coated wire question.

[mikepukmel]

Hi All,
I tore the cable out of the jack, on my cheap headphones, by accident. I had saved the cable from my (sob, sob) great old Audio Technica's that died a few years ago. I was surprised to find very thin enameled wire, like transformer wire, in the cheaper Sennheisers. At first, i thought it was aluminum, as solder would not hold. THen, holding it up to my mag light, I scraped it a bit with a xacto knife and could see copper. I could flatten out the strands, and sand one side, and get solder to hold, but its really weak.
Is there some solvent that can remove that enamel coating? Im using the term "enamel" but no idea what it is. Its on the wire pretty solid. I used very fine sandpaper to get some off, but there must be a way to make a small section clean.
Thanks
mike

[The Dude]

I'm sure it's not recommended, but I usually CAREFULLY burn off some of the coating with a cigarette lighter at the ends of that type of wire.

[Helmholtz]

A similar method was used with RF Litz wire.
The end of the bundle was dipped in denat. alcohol and then lit with a lighter. Directly using the lighter could have caused the tiny strands to melt.

[SoulFetish]

Same.
I've seen that a lot in premolded auxiliary/8mm cables and headphones.

[J M Fahey]

Mechanical sanding/scratching/scraping is not recommended.

In modern wire, neither a lighter flame.

Modern enamel is "self stripping", a *hot* soldering iron tip makes it evaporate with no residue and leave behind shiny clean copper, perfect to solder on.

[Wal_zz]

A hot iron is the method I've sucessfully used in the past. Just for interests sake I'll try the lit alcohol method and see if it is better or worse.
Can you still buy Litz wire these days? (Good for making high Q RF coils)

[nosaj]

A hot iron is the method I've sucessfully used in the past. Just for interests sake I'll try the lit alcohol method and see if it is better or worse.
Can you still buy Litz wire these days? (Good for making high Q RF coils)

[tedmich]

some use molten NaOH, but its very dangerous!

[mikepukmel]

Cool, thanks I'll try alcohol method and re-solder.

[Chuck H]

I usually try to strip back to untarnished lead and then splice. Copper oxide is impossible to solder. I've read that alkali rather than acid solutions should be used. I've seen baking soda and a toothbrush recommended.

I do love Juan and all his practical experience, but in bad cases where you don't have much wire to strip or the lead may be oxidized throughout the enamel jacket I think that physical abrasion can be a practical answer. Other than baking soda I've seen that some people use salt and lemon juice or vinegar. The acid and salt is a bad idea. I think it's just an internet hack method promoted by DIYers at the end of their rope that managed to get a surface clean more with elbow grease. You certainly don't want to LEAVE any salt or acid on the copper once it's clean. So I think a little baking soda and a toothbrush followed by a rinse with clear water and then dried with a cloth. Alcohol is fantastic for removing most anything else that migh be involved so you can finish with that. It evaporates quick enough and there's no rinsing needed.

My own experiences with oxidized stranded and solid copper lead are mixed. Good luck.

[mikepukmel]

I usually try to strip back to untarnished lead and then splice. Copper oxide is impossible to solder. I've read that alkali rather than acid solutions should be used. I've seen baking soda and a toothbrush recommended.

I do love Juan and all his practical experience, but in bad cases where you don't have much wire to strip or the lead may be oxidized throughout the enamel jacket I think that physical abrasion can be a practical answer. Other than baking soda I've seen that some people use salt and lemon juice or vinegar. The acid and salt is a bad idea. I think it's just an internet hack method promoted by DIYers at the end of their rope that managed to get a surface clean more with elbow grease. You certainly don't want to LEAVE any salt or acid on the copper once it's clean. So I think a little baking soda and a toothbrush followed by a rinse with clear water and then dried with a cloth. Alcohol is fantastic for removing most anything else that migh be involved so you can finish with that. It evaporates quick enough and there's no rinsing needed.

My own experiences with oxidized stranded and solid copper lead are mixed. Good luck.

Thanks Chuck, will give it another shot tomorrow. with baking soda, and also will try alcohol its holding up but only due I think to a very ugly tape job. For cheap headphones they sound OK and got me through virtual meetings during this covid thing. I could not believe how thin these wires are.