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I'm 60. Been soldering electronics and wires intermittently since 10 years old. Started with a radio shack kit using a soldering gun like in the pic. Too much heat they told me / that's why the kit didn't work after I was done.

Fast forward to now. Trying to solder some speaker wires, using a 100w soldering gun I got at a garage sale.

I know long wire will conduct heat away. So that's why I am using the gun - heat quick and get done, rather than a soldering iron with the heat getting wicked away / never gets hot enough to heat the wires to melt the solder (yeah, I know that - the wire should be hot enough to melt the solder, right?)

What am I doing wrong? Soldering iron gets hot. Will melt solder if touched to it directly.

I have the tip heating the splice. Solder not melting unless I get right next to tip.

Meanwhile plastic jacket is charring from the heat!

I cleaned thip of iron when hot with wet rag.

I cleaned / tightened the connections of tip / iron.

Use a smaller iron? Larger gun?

By the way, this is 14 AWG speaker wire. 1 lead is silver color, 1 is copper color. They run to speakers outside under an eave (doesn't see water, but does see humidity) to the finished basement with dehumidifier - not all that humid in general

The cable is likely 15 years old?

The copper color wire is greenish under the jacket along the entire length. Is that just age? never saw that before. Or humidity wicking along the length of the 100' run?! The middle of the run and the ends are the same greenish / copper mix. I'd wonder if that is part of the soldering problem. But the silver conductor is solver still / no oxidation.

THANKS!


charring of insulation

Old gun, but it DOES get hot / melts solder

What the joints look like before soldering

The copper colored leads have green oxidation.
 

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The green is corrosion.I think it is a reaction to something in the plastic insulation. I have seen this before.The wire is still fine.
However you won't solder that wire unless you get it clean and shiny.
 

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My Weller behaves the same way, so I’m curious to see what answers are suggested here. This thread did just prompt me to put new tips for the soldering iron on our shopping list for the next trip to town, thinking that might be the problem.

The solder that is used for electronics and other wiring projects has a core made from flux, so separate application of flux is not required.
 

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I have never use a soldering gun of that type. Only the pencil type. I'm only a novice all things considered. Green or other corrosion on wires will prevent it from wanting to solder. I also think the gun would be way too hot if the wire melts that much that quickly. Often dealing with some outside lighting wire that's acting up a bit and seen too much moisture. I try to clean wire ends with some abrasive pad, like the blue stuff to clean copper water pipes with and with a light acid wash, wash, rinse, rub, spread wires out, rub, wash, rinse ... to get them to look like copper again. Then I straighten the wires out, I pre-tin the individual wire units. before I bring them close together and join them with a bit more solder.

I should try to throw some flux on them next time :)

For what looks like an inline splice ... I'd probably just some crimping fastener. Clean the wires best you can. Slide in both sides into the unit. Crimp down once or twice. Done. If you want to prevent it from snagging in case you need to pull it behind a cabinet, desk, ... . Put some heat shrink tubing on before the crimp repair. Then shrink over the splice.
 

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My Weller behaves the same way, so I’m curious to see what answers are suggested here. This thread did just prompt me to put new tips for the soldering iron on our shopping list for the next trip to town, thinking that might be the problem.

The solder that is used for electronics and other wiring projects has a core made from flux, so separate application of flux is not required.
Even with rosin core solder, flux makes a huge difference in transferring the heat where you want it

Sent from my SM-G970U using Tapatalk
 

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Do not use plumbing flux for electronics. Residues of the flux will gradually eat the wires for months or years after you finished soldering.

Electronic flux (rosin) won't cause long term corrosion of the wires but is also not as strong as plumbing flux at getting off the last vestiges of green to make the soldering succeed.
 
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Check this out below and also this article

Is copper solder the same as electrical solder?



Image result for is there a special solder for copper


Electrical solders have a lower melting point (around 360˚F), while solders used in plumbing have higher melting points, usually well over 400˚F. This is why electrical soldering can be done using a soldering iron while most plumbing soldering uses a gas torch to heat up the metals.
 

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This is from memory.
  1. Put about 1/4 cup white vinegar in a glass. Add 1 tablespoon of salt and stir until salt is dissolved. Add a dash of salt and stir; repeat until no more salt will dissolve.
  2. Put about 1/2 cup water in another glass, add 1 tablespoon baking soda and stir until dissolved. Keep adding baking soda and stirring until water remains cloudy.
  3. Splay the stripped wire slightly, put it in the vinegar solution and stir with the wire for about 2 minutes. Individual strands should be nice and shiny. If not, stir a until all strands are shiny.
  4. Quickly immerse it in the baking soda solution and stir with the wire for 10-15 seconds.
The acid in the vinegar/salt solution should should remove corrosion. The alkali in the baking soda solution neutralizes any remaining acid.

Keep us posted.

73's
 

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I have been soldering for many years also. Like previously mentioned clean the wires as best as possible. Is the solder rosin core? If not must use a flux. The gun is ok as you said just heats up faster. I always puddle a little solder from gun to wires to conduct the heat.
 

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Clean the wires, forget the flux.
Use a thinner solder, and a lower wattage gun.....your gun is more than twice what you need.
You can't solder corrosion.....as you are finding out.
For speaker wire you can use the crimp on connectors.
It sounds like for 50 years you have been soldering incorrectly.
 

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Soldering electrical/electronic items you should use a rosin core solder. The soldering gun is fine for wires but not for heat sensitive components. As soon as the wire is hot enough to melt the solder it flows and job done. The big issue is the wires must be clean and free of oxidation.
 

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The soldering gun is fine for wires but not for heat sensitive components.
And some provide dual heat; pull trigger half-way for lower heat, all the way for full heat.

Weller
 
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Discussion Starter · #20 ·
Wow! Thanks everyone! I am using an (old) spool of really thin electronics solder. .032 " flux core. AS for the green being the issue for not being able to solder..... what about the tinned wire? Same issues of the (high) heat being drawn away from the joint enough to char the plastic.... but not melt the solder.

Found this page. now the debate of rosin vs. flux : ) ??


AS for why to solder? 'cause I thought it would be easy, I have the tools and thought it's better than crimp connectors.

And I was hoping the flux would deal with the corrosion / green for me.

Does flux dry out / dissipate on the spool? That page is from 1981.... I wouldn't doubt that solder is....40 years old! I had thcker solder (I usually wind some around the power cord so I always have some handy). but that was used up / found this thin stuff before the 'normail' diameter spool.
 
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