How to solder joints?

In this article, we will show you the basic techniques for making soldered joints. Most electrical and electronic faults in home appliances are caused by loose connections. So if you know how to solder, you'll be able to save a fortune in repair bills!

The basics

What is soldering?
Soldering is the process of using a soldering iron or soldering pen to melt solder around a connection. As an alloy of tin & lead, solder is a metal with a very low melting point (less than 300C) but with excellent electrical conductivity. This makes it ideal for repairing wires, faults and PCBs. What is a PCB?
A PCB is a printed circuit board. Whenever you open up an electrical item, PCBs are the green or brown boards that contain the electrical components. Two of the most common electrical faults are blown capacitors and loose wires. If you can solder, you can repair both of these problems.

Preparation

Prepare your tools
Use a heat proof board and a good quality soldering iron. If you are buying your first iron, make sure that it is of at least a power of 35W. Soldering guns are best avoided for delicate repairs. Prepare the joint
Most modern solder contains flux so you do not need to worry about buying an extra tub of this product. However, for the flux to work properly, the joint needs to be clean, so clean the area you wish to solder first and consider sanding it with a little wet & dry paper. Prepare the wire
If you are soldering a wire, then make sure that the stranded wires are twisted together to prevent them from fraying. Tin & clean the hot soldering iron
"Tinning" is the process of adding a little solder to a hot soldering iron tip. It removes any old oxidized material and is the first step in making a good connection. Make the joint
Heat the wire or PCB connection with the soldering iron for 3 seconds. Next, add three short dabs of solder whilst you continue to heat. The solder will follow the heat. Remove the heat and allow to set.

De-soldering

If you make a mistake or need to remove solder prior to repair, there are several ways to do this. De-soldering can be done through solder wick that soaks up melted solder or through a de-soldering pump. Ask your local electronics shop if you can buy these tools from them.

Safety note

Remember that soldering irons are extremely hot. Soldering releases some toxic gases and some unpleasant smoke. Be sure to work in a well ventilated area. If you prefer, wear a mask to protect yourself.