Soldering - Part 1

I have not had a chance to solder in a while, so I am taking this opportunity to start the soldiering series to help out those who are just getting into soldering. Today, at the makeshift Midnight Mods base, we are going to discuss soldering wires together. This is one of the easiest way to practice soldering. How much solder you use is very important to the bond of the components. To much solder can make it weak and not enough can not give you the desired effects. I will discuss more of what a proper solder looks like in the next article.

We need some soldering tools and some wire today. My wire happens to be the stereo harness for my truck. We need to solder these two wires together to complete the speaker harness for the stereo head. The harness is different from my 95’s, so we need to make this one work.

I’ve stripped the wires and put a little twist on them to keep them neat. The twist helps them pull solder in easier. A good twist is important. Over twisting can be bad, the twist also helps with structure. If you just solder the wires together strait, they will bend easily and that will break the solder. Remember, solder is a fusible metal alloy. We are heating up the wire and draw the metal into the object we have heated up.

To do this properly, we are going to use heat shrink tubing (in the picture above). These looks like little rubber sleeves, which is what they are. They shrink when heat is applied to them, and they protect the joint. You do not need to use this for practice, this is for a finished product.

I slipped the tubing on before soldering, cause, well you cannot put it on after you have completed the joint.

Here is the soldering iron we are using today. Lets plug it in and warm it up. This is a 40 Watt iron. I use an 18 watt at home. Heat is the killer for your components, you want to use the least amount of heat possible when you solder, this will reduce the risk of damaging components while soldering. Also, a higher watt iron is more likely to carbon up.

The tip looks really carboned up. Most people don’t know how to care for the tips, which is okay, I can fix this!  You can see the solder is not melting on the tip and sticking like it should. An iron, when taken care of, will hold solder on the tip when you apply solder to it, this is called “tinning the tip.” Just a hot iron will not transfer heat into the object, you use the solder on the tip as the medium to get a good transfer.

 

I could only find some steel wool. I usually use a scotch brite pad. They work good. Unfortunately, the steel wool was not abrasive enough, lets go to drastic measures.

 

You should file these while they are cold. it works much better so you can start the iron up with solder on it to tinn the tip properly. I already had it running. You can see in the second picture that it finally held some solder. I didn’t want to spend much time working on it, the tip was really flimsy compared to what I am used too. They generally are copper, because copper is a very good medium for transferring heat!

To get warmed up, we are going to practice some soldering to make sure the iron is hot enough, and the solder is flowing well. I have stuck this piece of wire into the vice and have twisted the end, now to give it a test.

Aww rats, that is way to much solder. Lets try this again.

There we go!

It is important to try and practice some while you do this, no matter how good you are, we always need practice, otherwise we end up with fried components, or over soldered connections.

Lets get these wires soldered together. You can see I have twisted them together in the middle trying to make one wire. The quick way would be to do it like a twist tie, but that makes the wire large, and the heat shrink would not fit over top of them.

I am actually not moving the iron. The iron is sitting in a stand on the bench, I am holding the wire over the tip with one hand and applying the solder with the other. This is a good work around when you do not have a pair of helping hands. It just takes more time because I cannot isolate the joint as easily. Also, with this method, the wires do not like to stay twisted together, so it takes more effort to keep them together before soldering, cause you are using one hand for solder, and the other to hold the wires.

We got them all together now, and we can start soldering. Make sure to keep the tubing away from the joint, this is another reason to use the least amount of heat. Wire transfers heat, and it will shrink the tubing. If you are really worried, throw on an alligator clip as as heat sync, The heat will travel to there, because heat’s goal is to even out across the surfaces, so it will go to the cold clamp. Do not use to tight of a clamp though, it could damage the wire.

 

To shrink the tubing I used a torch. This is not really the proper way to do it, but it works in a pinch. Do not ever hold the flame on the tubing, it will melt. You want to move the heat towards the tubing until it starts to shrink, and make sure you move it around and don’t hold it directly on one spot, this will also damage the tubing and cause it to curl up. The proper way to shrink it is to use a heat gun. You can still melt the tubing, but it is much harder. The gun is also more safe than an open flame. In a really big pinch, you can use a lighter as well.

 

And for the final touches, I’ll zip tie the wires together, and we are done! I know this article might sound a bit incomplete, but this is a practice type introduction for people wanting to solder. Take your time and practice on junk wire. If you are unsure if it is a good solder, send in a photo! I’ll be more then willing to help. If you are melting the casing on the wire while soldering, you are holding the iron on too long while soldering. Get the solder on and watch it flow, when it stops flowing, pull the iron away. Stereo is working great by the way, if anyone is wondering.