Soldering Corroded Wires

[Bestathook]

I think all of us have found a situation where there is a short stub of wire, dark with corrosion, that needs to be soldered, Often, the solder just beads up and won't lay into the wire, regardless of heat application.

There is a solution. Here in Florida there are lots of pine trees. If you find one that has been cut, or battered by drifting logs in a storm, there are often beads or gobs of hard dried pine resin near the broken bark. Dried resin can be found on some pine stumps.

Gather a quantity of these resin balls and chips, and melt them in a small tin can. Pour the clean clear resin into a mold (plastic jar bottom works well), and let it harden to form a large ball of crystalized resin. When the resin (or rosin) has hardened, cut away the mold.

I scrape the strands of wire as much as possible with a knife, then twist them back together into a strand. I then push the strand into the gob of resin with the heated tip of a soldering iron, till the wire is totally coated and penetrated with melted resin. Expect a bit of smoke. Then it is soldered in the normal way.

We have all used rosin core solder, but the small amounts in the core are insufficient for some jobs, The heavier coating of rosin works much better.

I suspect hard rosin can be purchased as well. My fiddler friend got some at a music store for his bows. Here in the South, resin has been gathered for centuries for turpentine, and the old "cat face cuttings" are still fairly common, though the cutting ended in the 50s. But there is still hard resin around the cuts. The Indians made glue mixing resin and tallow.........but that is another story for another blog.

[captain58sailin]

Thanks for the insight! I'll start gathering some in the spring.

[Jim Cate]

Another approach is to buy a tin of resin (rosin?) based soldering flux,available commonly.

But IME, soldering corroded wires is not always a good idea, even if possible!

Cheers,

Jim

[goboatingnow]

Rosin is available widely , if you are really pushed use something like an acid flux , like Bakers soldering fluid . Just wash the connection well afterwards ( isopropyl alcohol )

Acid flux will outperform Rosin but has obvious drawbacks


Dave

[tbodine88]

Draw back, If you fail to wash well, the connection falls apart long after you are paying attention to it, but now there is no wire left to solder.

[Cheechako]

or just buy a little tin of NOKoRode soldering flux. Been using it for about 50 years now. Working on antique electronics it's pretty much mandatory... old solder joints just wont melt without it. It would be nice if you could clean the wire though, maybe with weak acid? and then do a good crimp terminal or solder.Probably a big PITA to do that though. (acid, rinse, dry etc)
http://www.amazon.com/C-R-Laurence-N...A3980GNRT360TO

[Jim Cate]

If you use acid flux, rinsing with a sodium bicarbonate solution rather than plain water does a good job of neutralizing the acid.

Jim

[Bestathook]

Using insulated wire, any liquid moves up the wire and under the insulation by capillary action. A neutralizing liquid may neutralize it or may move it farther along. That leaves me unsure if I got it neutralized or not, and leaves salts where the liquid was.

A dip in acid is fine with bare wire, with disolved baking soda rinse to neutralize it.

I'll try some NoKoRode. Does it need any rinsing or neutralization after being used?

And yes, soldering corroded wire is not ideal, but I have yet to see a floating hardware store on the water. Sometimes I have to make do until......

But as one friend put it, temporary measures often end up permanent until they fail again.

[Cheechako]

NoKoRode: Nope just use as is.. it flows the solder like heck. For those black copper wires, I would wire brush them with a dremel circular wire brush regardless. I hate resusing those wires really, but sometimes you just need to I 'spose....

[Wotname]

Agree with all the points made so far and especially with the undesirability but the occasional necessity of soldering corroded wires. This is another reason I prefer tinned wire.

Tinned wire does not stop the wire from corroding but does slow it down a lot. I have always found corroded tinned wiring re-solders a little easier than untinned. YMMV

[Canibul]

In a pinch, you can use most grocery store toilet bowl cleaners to clean the corrosion off. Active ingredient is hydrochloric acid. Dip the black wire in undiluted Sno-Bol, for example and let it sit for a few minutes. It will take black wire back to shiny. Then neutralize and rinse and solder. If the wire is corroded to the point where it's brittle, forget it.

[LagunaPaul]

I'm was a process engineer for an electronics assembly plant and know a thing or two about soldering. While using pine rosin will work, its a lot of work when you can buy a tin of solder flux and keep it in the soldering tool box. It will last for years. Electronics stores and plumbing stores will have various tins of the stuff to choose from . Plumbers and Electronics Technicians use the same basic stuff.

Basically, a flux removes the oxide layer that forms on all metal surfaces when exposed to air. Oxide is corrosion. Rosin, Mildly Activated Flux, or RMA Flux as its known in the industry isn't the most aggressive flux. It does have the advantage in that if you don't clean it completely off the solder joint with a solvent when you're done soldering, it won't eat through your solder joint for several years. Another way to go, and the flux I use is an Organic Acid Flux, or OA Flux. It is water soluble, but it is aggressive. You must do a thorough job of cleaning it with water (De-ionized water is best) or it will eat up your solder joint. It is an acid after all.

But, if you're lost at sea and need something to work as a flux, pine pitch will work. You just need to have that pine tree float by ....

Edit: I wouldn't clean OA flux residue with soda. Although soda neutralizes acid, it will leave a reside on the circuit/wire. This can cause current leakage; not good on wires because it can lead to sparks/arcing in high voltage applications and really, really not good on sensitive digital electronic circuit boards. Just clean it with DI water if you have it.

[bill good]

My method is to scrape all the wires & re tin as much as you can, retwist & then wrap a strand of clean wire along the length to solder like a splice. re tin the length & you can solder the worked lengths together. GUD was the brand name of a paste flux used for electrical work that came in a small tin. It would help to keep some thing like that on board.

[GordMay]

Greetings and welcome aboard the CF, LagunaPaul.

FWIW: Nokorode Paste Flux is NOT recommended for electronic use.
➥ Nokorode(R) Regular Paste Flux

[d design]

I like to soder wires to NASA specifications...lol basicly it requires you not to twist the two wires togeather and solder but to tin each wire and solder them togeather parallel to each other. This method was tested by nasa by stretching a wire with this type of solder joint untill it snaped, and it dident snap at the solder joint!