How to Solder Two Electrical Wires Together

Click to enlarge - Finished job

This article will describe how to solder two electric wires together properly so the joint will virtually last forever and not corrode or come loose.

Things You'll Need

• Soldering gun or iron.
• Soldering paste or tinning flux
• Solder, lead free, rosin core.
• Electrical tape and/or Liquid electrical tape

Instructions

1. 

   This picture shows the two wires that are to be soldered together. Also shown in the picture is a wire stripper that's used for stripping the insulation off the wires. Stripping can also be done with a knife.

2. 

   This picture shows the wires being stripped of insulation back about one half inch or so. This dimension is not critical. The wires just need to have enough wire showing to be easily soldered to one another.

3. 

   Shows dipping one of the wires into the tinning flux. Each wire will be dipped into flux just before soldering. This is a critical step. Flux is needed to chemically clean the wire so the solder will adhere properly to the copper. If flux is not used the chances of getting a poor soldering joint is almost guaranteed. Poor soldered joints have a tendency to heat up and the chances of them coming apart is very good.

4. 

   If you have some heat shrinkable tubing now is the time to slip a little of it over the wires before you join them. Line up two of the wires parallel and touching each other, heat up the soldering gun and melt some solder over the joint, flowing it evenly along the whole joint.

5. 

   This shows the Tinning Flux (it is sometimes called soldering paste) and the roll solder. The flux is about the consistency of Vaseline and it sticks readily to the wire if you just dip the end of the wire into it. Don't need a brush or anything. The solder is rosin core and lead free. It is most important to use rosin core. Some rolls of solder have acid in them and this will corrode an electrical joint. Do not use it.

6. 

   Once you get the two wires soldered together it is time to slide the heat shrinkable tubing over the joint and heat it up with a match or lighter to shrink it. You have to keep the two wires insulated from each other or a short will develop. You can wrap the joint with electrical tape being sure to keep the wires separated. In this case heat shrink tube was used and it is covered with Liquid Electrical Tape.
   Job is now complete.

Tips & Warnings

• It cannot be stressed enough that tinning flux must be used when soldering copper together. If the wire happens to be aluminum solder will not stick to it.

• Use safety glasses to prevent any spatters from getting into the eyes.