Soldering Guru's!

[Phil G]

Hey all,

So I've encountered something strange, a new one for me anyway.

I'm attempting to solder some leads to some purple/pink led rope light and it absolutely will not take the solder. I have a nice clean Hako soldering station which is easily hot enough. In fact I'm able to heat the wires to a temp that will melt the solder, but the solder simply balls up and will not flow into the wire.

I changed tip, cleaned and cleaned. Still same results. Then I checked on some blue led rope light and it worked just as it should, took the solder like a champ, as it also did when I soldered the electrical chord leads. Just for kicks I then jumped back the purple rope light and once again, no dice, won't solder.

Have any of encountered this before? I'm a sound engineer by trade and have soldered countless cables in addition to plenty of electrical repairs etc... I've never had this happen.

Any tips would be really appreciated. Also, FWIW I'm wiring up mine and my fiance's bikes with a simple 12v battery system, and as such the rope light is the 12 variety.

Thanks so much!
Phil

[Captain Goddammit]

Is the wire clean, and did you try using some flux on it?

[Jackass]

Sounds to me like you have some contamination in that copper if the hot solder just keeps rolling off. Could be from the manufacturing process.

[Phil G]

I'm off to buy some flux right now. I'm using rosin core, but I'm gonna pick up some of the chunky stuff. Wire is super clean, brand spankin' new, I've even cut and re-stripped multiple times.

So, contaminated copper? Would not surprise me, its chinese. Any suggestions?

Thanks!

[Jackass]

Flux. I've had that same thing happen only it's usually on older wire that's been exposed and has lost it's bright and shiny status.

[GreyCoyote]

Scrape it with a scalpel under high magnification and see if the substrate is actually copper and not aluminum. If so, you will need a special solder and flux, but it can be done.

With the current price of copper, it would not surprise me to see aluminum in there. They are already starting to use it in one type of EL wire.

[Jackass]

I bet you're right GC, they are supplementing copper with aluminum more and more these days. Transformers are almost always wound in aluminum anymore, that's why all these new chargers are much lighter than their predecessors (that and micro pulse "smart" technology).

[Phil G]

Alright I just loaded up on flux and some silver solder. Its worth a try and not bad to have regardless.

However I'm starting to suspect its aluminum. If thats the case what are my options?

Cheers!
Phil

[BBadger]

I'm guessing that the wire is not fully stripped, especially if there is waterproofing gel on the wire. The wire may appear to be completely stripped, but there's actually a thin layer on there. The soldering iron then melts the solder, but the wire itself doesn't get hot and the solder just beads up on top of the rubber/plastic.

Try really scraping that wire down. Get out a knife and strip it until you see the wire looking shiny. Better yet, see if you can find a soldering pad or something like that to solder onto. Finally, maybe you'll just have to take a knife and puncture into the wire itself so that you can reach the core.

[Phil G]

Alright, so here is where it stands. I fluxed the shit out of it, no deal, I used the silver-bearing solder, didn't matter. I scraped and sanded and all kinds of shit, still nothing would stick. As a matter of fact I could heat up the wire enough the melt solder (without touching the iron) and it just balled up and ran right off.

I think its aluminum, its gotta be. I'm not sure if there is such a thing as aluminum solder but I'm going make some calls tomorrow.

That being said, I just said screw it and used a couple male-female crip connectors and made the best of it. I also made sure to heat shrink the hell out of all my connections. Everything works, just not as stable as I'd like. Fortunately if anything happens on the playa I'll be able repair it no prob.

Thanks for everybodies help! Can't wait to be at BRC!

Phil

[BBadger]

Looking around, supposedly you can use some heat resistant oil and put it over the aluminum, scrape, and then do the soldering without the aluminum oxidizing.

[FossaFerox]

If you're okay with totally cheating and doing something that's NOT okay, but will probably work: Form a good mechanical connection by tightly twisting/splicing the wires together and solder the twisted connection. You will form 95% cold solder connections on the aluminum wire, but about 5% of it will be solid/conductive, and a mechanical connection isn't terrible to begin with. I had to do this on one of my projects and it works fine, just make sure you have some kind of strain relief so nothing tugs hard on the connection. Ask us if you don't know what that means.

[GreyCoyote]

There is indeed aluminum solder and flux. They must be used together. There is also a paste version designed for reflow soldering that will do in a pinch. Do NOT use aluminum brazing products. Very different composition and high melting point. Useless for this work.

Contact Indium Corporation. They make an indium-based solder and flux pair. Expensive as hell, but works nicely. FWIW, a variation of this same solder allows you to solder to glass. No joke. Google it.

[rufus13]

Crimp a terminal to clean scraped wire.

Aluminum caused a lotta house fires in the 1970's. High TempCo of Al wire causes pulling away of connector until it's bouncing around sparking in a wall, after a couple of years, well after warrantee period. Al wire essentially banned for domestic service.