Large Scale Central

Soldering Oxidized and Corroded Copper Wire

Electronics
#1

Anyone who uses direct burial, copper feed wires to power trains, lights, or whatever in the outdoor environment knows that regardless of how well you try to seal the wire, it oxidizes and corrodes within its insulation in the damp environment. The oxidation forms a dark/black film on the strands that will not take solder.

In the past, I would used sand paper or an X-acto on the wire to scrape off the film enough to get the wire to take solder.

I am now redoing my ground signals, changing the wooden stantions to concrete, and many of the wires going to the LEDs had corroded apart from their direct burial Malibu feed wires. All of the wires (even those still connected to the Malibu wire) had the oxidation film.

This wire to teh LEDs is small gauge and sanding it for soldering would probably remove most of the strands. The connections at the LEDs were still good, and I really didn’t want to replace the wires and deal with those again.

Having had such good luck cleaning the brass track with vinegar, Linda suggested that I try it on these wires. I put some vinegar on a paper towel and wiped the strands. This did a bit to remove the oxidation, but not enough.

So I stripped back some insulation and soaked the ends of the wires in a small cup of vinegar for two days. When I pulled it out, the copper was bright and shiny and the wire took solder like it was brand new.

#2

just dip them in brick acid and neutralise with water, 2 minutes,

#3

might want a weak solution of baking soda for neutralizing, if it’s soaked for 2 days, then you might need the neutralizer to soak a bit too, dipping in water might leave some acid behind.

Greg

#4

A vinegar and salt solution cleans brass and copper quite well. Todd next time add a pinch or 2 of salt to the vinegar.

The navy, way back when, used a solution that contained vinegar and salt to clean the brass on ships, it was called Ketchup.

#5

a with any acid use inc vinegar you must flush well with water, just yesterday i dipped some door furniture and polished it up

it gets into areas that are hard to get too, you still need to polish it but its so much easier with all the paint and oxidation removed

and lets face it they use acid to etch kits, you dont see those covered in acid corrosion so it must be ok provided you clean it after

i find vigorous shaking in water is enough

#6

Optic fibre might be a way to go for signals…

(Not that I know anything about it) but I saw that some of the aero guys have been using it to control servos.

Just wondering if it could be applied to rail signals???

Just a thought.

#7

The reason I mentioned the extra effort, is you cannot wash stranded copper that is under the jacket, the water or acid solution wicks up out of sight.

Quite different from washing a flat sheet of metal that has no hidden nooks or crannys.

It’s much more difficult to wash this “hidden away area” out completely… and some residue will still live there…

Greg

#8

good point greg and worth noting

#9

I’ve learned this the hard way, I have a small lot, but a lot of outdoor lighting, run by 8 (yep that’s eight) 300 watt transformers. I have not counted the number of lights, but I’ve learned a lot about landscape wire, I have a lot. I learned what it took to keep corrosion out of connections buried in the ground and/or subjected to moisture.

I also wired my layout with 10 gauge stranded wire and have had corrosion issues up inside the jacket. Clearly, the gauge of the strands in the 10 gauge home wiring is different than the landscape wire.

But, even with the much larger strands, I have had issues with the 10 gauge stranded up under the insulation. You just cannot stop moisture wicking up inside.

Regards, Greg

#10

I have had some success with dipping the bare ends of stripped wire into polyurethane varnish and letting that wick up under the insulation.

You then have to remove the varnish prior to soldering.

Encapsulation joins in epoxy can prevent moisture ingress, I once mad a waterproof joint by mixing epoxy and filling some heatshrink tubing with it, the heat given off actually shrunk the tubing,

#11

I’ve been soldering old copper and old brass for several years now, even to repairing rail clamps that have started to split. What works for me is to mechanically clean them with a wire brush, the dip the copper into flux. Solder the collected wires together, then twist the two wires together and solder them together. If you’ve got shrink tubing, place that on the wire before soldering, otherwise use electrical tape to cover the solder joint. In a dry climate that should be all you need to do. In wet climates, you may still be some corriosion, but unless the copper corrodes through ALL the strands electricity should make it thought. Electrons are tricky devils!

#12

Dick, yes they are. the other day they melted the insulation off a wire and burned the skin on my finger. And I didn’t even know that I had made them mad.