This is important, as solder sometimes has a tendency to spurt, sending small droplets of molten solder into the air. Since the droplets are small, they do not generally cause damage to the skin or clothes, but have the potential to cause serious damage to unprotected eyes.
The tip of the soldering iron can get as hot as 700 degrees during use, which can cause serious burns to skin and melt most plastics. This means that caution must be observed when handling the iron.
Metal objects like wires and resistor leads conduct heat very well, and may be heated several hundred degrees by the soldering iron, which can lead to severe burns.
Ensure that the parts or wires that need to be soldered are held securely in place. Devices like clamps, vices, or tape can help with this. Ensure that nothing sensitive to heat is touching the area that is going to be soldered.
Turn on the iron and set the temperature to 700°F (370°C), and give it around a minute to warm up. Next clean the tip of the iron by wiping it on a wet sponge or a metal sponge.
Hold a strand of solder in one hand and the soldering iron in the other. Place the iron on the joint you want to solder and feed the solder onto the joint. The solder should melt as it touches the iron/joint. Apply enough solder so that the connection is mechanically and electrically stable. Applying too much solder can make a connection difficult to desolder, so be careful not to use too much.
A good solder joint should be shiny and cone shaped. If the joint is dull, it is the result of "cold solder," which occurs when molten solder is added to the joint, instead of being melted onto the joint itself. If the joint is blob shaped, that might mean that the solder spread to other connections, so be sure to check for shorts.
Always wear safety goggles/glasses, be careful with the iron, and don't touch anything while it is being desoldered
Since braid is made of finely woven copper, it conducts heat very well. This means that when the braid touches the iron, it heats up very quickly and will burn your hands if you are holding on to it.
Ensure that the parts or wires that need to be desoldered are held securely in place. Devices like clamps, vices, or tape can help with this. Ensure that nothing sensitive to heat is touching the area that is going to be desoldered.
Turn on the iron and set the temperature to 700°F (300°C), and give it around a minute to warm up. Next clean the tip of the iron by wiping it on a wet sponge or a metal sponge.
Get a clean strand of braid to desolder with. Pick up a strand of braid with a pair of metal tweezers in one hand and the pick up the soldering iron with the other. Use the tweezers to press the braid onto the area to be desoldered, then apply the soldering iron onto the braid. After a short amount of time, the solder should melt and be absorbed by the braid. Be careful not to keep the iron on the connection too long, as you run the risk of burning the parts/board you are trying to desolder. It is often best to wait a couple minutes between desoldering attempts to give the parts and board a chance to cool down.
How much solder is still left on the joint? Sometimes multiple attempts need to be made to get all the solder off of a connection. Sometimes it helps to add more solder to a joint you are trying to desolder. Also check that while desoldering, you did not inadvertently solder or desolder other connections on the board.