How to solder loose ends together (1 Viewer)

[RobertCharlotte]

Very basic question.

I noticed in a different thread someone mentioning soldering the loose ends of speaker cable together to keep them from unravelling and I was wondering if I could get some pointers on this technique.

 

[Dave Poehlman]

Just twist the wires together and then cover the twist with solder.

 

[RobertCharlotte]

I guess I had a picture of making a little puddle of molten solder and dragging the wires through it. Thanks!

 

[Marc Rochkind]

Some more detail:

As I learned when I was about 10 years old, "solder is a conductor, not a glue."

So, here's how to solder:

1. The wires must be clean.

2. The joint must be mechanically sound absent the solder. In other words, the solder should be almost superfluous.

3. Twist the wires tightly and then clamp the wires by their insulation so they don't move while you are soldering.

4. Place the hot iron or gun on the joint from below, as heat rises. After a few seconds, touch the solder to the wire far from the tip of the soldering iron or gun. Do NOT touch the solder to the iron or gun, as it will melt right away and therefore you can't tell if the WIRE is hot enough.

5. When the wire is hot enough to melt the solder, it will flow towards the heat. You don't need much at all. Just enough to flow into the joint.

6. Remove the solder and the iron or gun and let it cool.

SPECIAL ADVANCED TECHNIQUE: When you touch the iron or gun to the wire to begin heating it, touch the iron or gun directly with the solder to create a pool of molten solder between the iron or gun and the wire. This helps the heat transfer. This amount of solder plays no part in the joint itself--it's just there to help with the heating. The rule about not touching the solder that will flow into the joint directly to the iron or gun still applies. In other words, you touch the solder once to the iron or gun, and (after a few seconds) a second time to the end of the wire.

Hope this is clear!

By the way, you use rosin core solder for electrical stuff, never acid core, which is for a different purpose.

 

[Bob Jr]

Marc Rochkind
Thanks Mark. You should re-post this under, “what every newbie should know”.
I’ve soldered many times and it takes discipline to wait for a hot joint and not touch the iron and say, “now I finally see a puddle.
Kudos
Bob R.

 

[RobertCharlotte]

Very excellent reply, Marc, and I think much more what I had in mind when I asked the question. Thanks!

 

[Marc Rochkind]

Thanks for the kind words... I added it to the "What Every Newbie..." thread, although I think that thread has now gone way beyond newbie's!

 

[Wayne A. Pflughaupt]

An excellent primer, Marc, from a guy who has been soldering for almost 20 years.
Only a couple of things I would add:

• Be sure and tin the iron as well as the wire.
• Make sure the soldered area is not disturbed or moved until the molten solder hardens (or appearance-wise, goes from “wet” to “dry”). If you do you will get a “cold solder joint” which will quickly fail. Properly applied solder will have a somewhat shiny appearance; a cold joint will look like flat silver spray paint.
• As Marc mentioned, don’t over do it. The wire should be fully saturated with solder, but not to the point that you can’t make out the texture of the wire. There should not be a glob of solder hanging from the finished product.

Re the “Advanced Tips:”

When you touch the iron or gun to the wire to begin heating it, touch the iron or gun directly with the solder to create a pool of molten solder between the iron or gun and the wire. This amount of solder plays no part in the joint itself--it's just there to help with the heating. By the way, you use rosin core solder for electrical stuff.

The rosin is a flux that serves as a cleansing agent and purges oxygen from the process (most welding processes use a burning flux [that’s the smoke you see] or forced inert gas to purge oxygen), which (I think) is actually what helps the solder flow. Try to solder with solid-core (no flux) solder – it doesn’t work well (if at all).
Again Marc, great job.
Regards,
Wayne A. Pflughaupt

 

[Juan Castillo]

Wayne says :
"Make sure the solder point is not disturbed or moved until the molten solder hardens (or appearance-wise, goes from “wet” to “dry”). If you do you will get a “cold solder joint” which will quickly fail. Properly applied solder will have a somewhat shiny appearance; a cold joint will look like flat silver spray paint"
Wayne, would you say that this should be done to all soldering irons before using ? Kind of like burning in the soldering iron? I guess my question really is, if you use the same kind of solder all the time (which I am sure you do not, considering your extensive use of these tools for different projects), would it be necessary to do it more than once? Should a desoldering braid be used to clean the tip after each use, and reapplied for next solder? Or can more be added to existing coated tip? I have never cleaned mine, and am wondering if this would help it heat up quicker? I am sure your is prolly a nice unit which heats up fast, but since mine is a cheap RS unit, would it help?Thanks for your advice.. sorry if I ticked you off on the other soldering thread, really not my intention

 

[Tom Morgan]

Marc has a good response, and I will just add that:

"By the way, you use rosin core solder for electrical stuff, never acid core, which is for a different purpose"

The different purpose for acid core is for soldering componets to circuit boards, where the is no insulation. Acid core board solder will do nasty things to insulation. One advantage is it cleans with water.

 

[Wayne A. Pflughaupt]

Juan,
I can see I’ve done it again (see my reply to your most recent post on the “Splicing” thread) That’s what I get for trying to compose technical replies when I’m tired and bleary-eyed. :b
By “solder point” I meant the place or thing that is being soldered. I've edited the comment. You can’t move it until the solder has hardened or you will get a cold solder joint, which looks “flat” instead of “shiny.”
I can see you are talking about the tip of the actual soldering iron. Obviously any solder residue on the iron will remain molten until the iron cools down after it is turned off or unplugged.
Since you mention it, I overlooked on Marc’s post that it is normal to “tin” the iron (melt a dab of solder on it) just before you start soldering. He did allude to essentially the same thing in the first sentence of his “Advanced Techniques,” but this is more accurately a “standard” technique that should always be used. As mentioned, the flux will help the solder flow when the wire (or whatever you are soldering) reaches the right temperature.
After the solder joint, connection or splice is completed the tip should be immediately cleaned. This is typically done by thoroughly wiping the tip on a wet sponge. There are “special” sponges you can buy for this, but after I lost mine I started using a common kitchen sponge – works just fine. The wet sponge immediately hardens the solder residue (by reducing its temperature) so that it is easily removed from the tip of the iron.
So, you tin the tip just before you start each solder joint, and clean it immediately afterwards, before you proceed to the next joint. Hope this makes sense.
Also, make sure you thoroughly clean the tip after the project is completed before you turn off the iron. As I mentioned on the “Splicing” thread, old flux becomes a corrosive agent and it will shorten the life of the tip. You might even see the tip become pitted over time as a result of latent flux residue.
Cleaning has nothing to do with the time it takes the tip to heat up. Juan, if you’ve noticed your iron takes longer to heat up than it used to it is probably because the tip needs to be replaced. They don’t last forever, even if you keep them properly cleaned. Another sign of a bad tip is that doesn’t get as hot as a good one. If you notice you have a hard time soldering stuff that used to be easy, that’s a sure sign the tip is on its last legs.
Solder braids are most commonly used for removing solder on circuit boards locations where a bad component (resistor, capacitor, etc.) needs to come off.
I have three irons, but none of them are fancy or expensive: a 10-watt for delicate work, a 40-watt for general use, and a 100-150 watt gun for heavy-duty stuff. If you solder often, Juan, or even only a couple times a year, I recommend getting a decent iron. Since I’m no longer in the install business I don’t solder as often as I used to, but I still seem to find something to solder several times a year, and I’m glad I have a good iron when I do. I recommend the Weller WP series; been using mine for 10 years now. They are excellent “semi-pro” irons and reasonably priced. The 35-40 watt irons cost a little more than the 25s, but I find the 25w’s are just a little “weak.” I find my 40w iron meets about 95 percent of my soldering needs. If money is an issue you should have no problem picking one up on ebay for no more than your “cheap RS” iron cost.
Hope I covered everything. If not let me know.
Regards,
Wayne A. Pflughaupt
P.S. We passed by Bryan on the way to Dallas last weekend. Someone needs to tell the Chamber of Commerce to put some more restaurants on Hwy. 6!

 

[RobertCharlotte]

a 100-150 watt gun for heavy-duty stuff

I started to work on this project a this past weekend when I noticed that my solder gun is 100 watts. Do I run the risk of damaging the wires I'm soldering, or will I just get them warm faster? Or both?

 

[Ted Lee]

great info on soldering!
btw - for ends of speaker wire, aren't you only supposed to solder the very ends of the speaker wire and not the entire exposed part?
i've heard solder may inhibit the wires "sound conductivity"?

 

[Richard Travale]

This is a great thread especially to the solder newbie.

Wayne, so you are saying that if I were to get just one iron/gun that you would recommend the 35-40W model. It would be delicate enough that I wouldn't destroy some things yet powerful enough to do heavier solders with a little more work?

 

[Wayne A. Pflughaupt]

I see this thread has been resurrected!

I would again like to recognize Marc Rochkind’s excellent instructions early in the thread. It was never my intention to “hijack” this thread; since Marc was the first one to take it on, I’m going to give him the opportunity to respond to these questions first, if he wants to.

Regards,

Wayne A. Pflughaupt

 

[Wayne A. Pflughaupt]

Robert,

Wayne, so you are saying that if I were to get just one iron/gun that you would recommend the 35-40W model. It would be delicate enough that I wouldn't destroy some things yet powerful enough to do heavier solders with a little more work?

I use my 40-watt iron for probably 95% of everything I solder. You can use a super-skinny tip for wire gauges down to 22ga., (again, you might have to be careful to get in and out as fast as possible with the more delicate stuff) and even some board work with care. A broad tip will cover most larger wire gauges to 12 ga.

Regards,

Wayne A. Pflughaupt

 

[Richard Travale]

Thanks Wayne.

 

[RobertCharlotte]

Thanks, indeed, Wayne! I'll try that cold-on technique and let you know how it goes.