Jan. 17, 2012
So I remember when I didn’t know how to solder and everything I tried to solder I messed up and would get extremely frustrated because I knew it was simple. I just didn't know what I was doing wrong... It would have been great if College had taught me that... But no... They didn’t. I learned soldering from a friend of mine at Lexmark who used to solder for NASA. I thought I put some basic stuff together to help others.
In this tutorial we will be making wire unions. THIS IS NOT THE PROCEEDURE FOR SOLDERING INTEGRATED CIRCUITS, CIRCUIT BOARDS, OR OTHER ELECTRONICS. THIS IS ONLY FOR WIRE TO WIRE JOINTS.
- Soldering Iron
Soldering Iron doesn't have to be an expensive one. The one I was using was a cheap one from Radio Shack.
- Solid Core Solder (No Acid or Rosin)
Solder could have rosin in it but I find it easier to work without it and rely on the flux.
- Liquid Flux
Liquid Flux works best... In a tight situation I've used plumbers Flux and it work...
- A File and/or Brass Shavings
- Shrink wrap
- Heat gun or lighter
Maintaining your Iron
Before you start and/or If you leave your iron on too long and it gets black you'll have to clean that puppy with your file to get it back down to the copper then put some flux on it. Corrosion is why you can’t get the solder to stick to the Iron... Once filled the Flux will clean any other impurities off of the iron (when it’s up to temp).
Flux cleans the metal of impurities and makes the flowing of solder much easier.
They will help you clean your iron of Solder so that it doesn’t become corrosive when left on the iron. Its optional.
Locking hook principal
Using locking hoops generates a mechanical bond that has a higher tensile strength than just solder alone. Wires soldered together this way will have a stronger bond allowing much more tension to be applied to the bond.
Part 1: Soldering bare wires only
Take your wires and shave it back using a knife or speed strip tool (I like the speed strip tool myself).
This is a good time to put some shrink wrap on
Twist the wire threads to make it easier to work with and give it some rigidity.
Apply some liquid flux to the wires to be joined.
Apply your heated iron to the fluxed wires.
Get some solder on your iron. And I don’t mean a heaping GLOB. Just a little
Apply the heated Iron with solder to your twisted and cleaned wires. It should take no more than 3 seconds to get the solder on the wire... If it takes longer your Iron is not hot enough or the wire was not cleaned properly.
Take some needle nose pliers and put a hook in both of your wires by rolling your pliers.
If you forgot your shrink wrap slide it on now or your regret it.
Interlock the hooks in the wires.
User your pliers to close the hoops.
Put a little more solder on the interlocked hooks but don't overdo it.
Put your shrink wrap into position.
Heat your shrink wrap with your Heat gun. Make sure to move from side to side... Don't hold the heat in one spot to long... Especially with a lighter. You will burn the Shrink wrap easily with a lighter.
With any luck you should have a good solid fairly water tight and strong union. (Water tight.... that is if you use the proper size heat shrink)
Part 2: Soldering with crimp connectors
The basic idea behind soldering wiring with crimp connectors is the same as that without. You'll want to start out by stripping the wire. These are some different wire strippers and crimpers. The yellow handled one is an 'automatic' stripper which will cut an remove the insulation in one squeeze of the handle, the middle one is a 'manual' stripper, with this one you'd insert the wire into the appropriate sized cutting hole which will cut through the insulation this pair also has a few various crimping sections (typically for insulated crimps), the blue handled one is a crimper only, and is the type of crimper which is used mainly for uninsulated crimps which is the kind we will be using here so that we are able to solder them.
I prefer to use the automatic type stripper, they're easy to use and easily handled. Here we put the portion of the wire that we want stripped out to the right of the centerline, as we start to squeeze the handle together, the little holders come down and grip the wire:
As we continue squeezing the handle, the holders pull apart and separate the insulation, and remove it from the wire:
Just like in part 1 we'll twist the wire strands together. Then slide them into one side of the crimp, you'll insert this into the correctly sized part of the crimpers and squeeze the handle together to crimp the wire strands in there:
You want to put on your heat shrink tubing at this point, and slide it up the wire a little ways. Then you'll do the same with the other wire on the other side of the crimp. You'll notice the small opening in the center of the crimp itself, this is the part where we'll start soldering at.
Now take your soldering iron and heat up the crimp. How we want to do this is to apply the heat to the crimp and heat it up enough to melt the solder itself. When it gets hot enough (which shouldn’t take long, maybe 10 seconds or so) keep the soldering iron on it applying heat, and touch a little bit of your solder to that opening on the crimp, the solder will flow freely into the opening, keep adding small amounts until you feel there is enough in the, or that little opening gets filled. It won't take much solder. Then I like to also flow a small amount of solder into each of the ends of the crimp, you can see in this pic how there is a small amount of solder at the strands coming out of each end of the crimp. In this example I used rosin core solder rather than fluxing. The conductivity of the joint will be just as good, but the rosin will leave a discoloring to the solder.
Then you'll want to seal the solder joint up. you can either do this with double walled heat shrink, which has an adhesive in it, that when heated, activates and seals the heat shrink to the wire and solder joint to achieve a watertight seal. Or if you have single wall common heat shrink you can add a little RTV on the solder joint before you pull the heat shrink tubing over it. That way, as you heat it, the shrinking of the tubing will spread the RTV around, and once the RTV is dried, you will also achieve a watertight seal.