Soldering is the act of merging different pieces of metal together by using heat. The metal of two different pieces are melted and fused together so they remain stable.
Solder is a often made of several metals mixed together used to fuse other metals together that cannot be melted themselves. Soldered metals are not as strong as the original metals, but can be strong enough and conductive enough for electronics, pipe soldering and making jewelry.
Electronics soldering is one form of soldiering that requires a lot of precision. A soldering gun with a very small tip is needed so that the parts of the electronics that need to be soldered can be sealed without damaging or interfering with other electronic parts.
The type of solder used for electronics is usually a combination of lead and tin. Lead was once extensively used in soldering, but there was a significant concern for lead poisoning, since the lead soldering would corrode over time and would release lead flakes.
While lead is still used in electronics, lead is not used as much when soldering products such as pipes because leakage in the pipes can cause lead to seep into drinking water.
Copper and Brass
Copper and brass solder very easily, binding to other kinds of metals. When some metals are bound together, they need to have special fluxes that help facilitate the binding and these fluxes can be very hazardous.
Tin is a solder that tends to be used in place of lead soldering to avoid lead poisoning, though copper and silver are also commonly used. Silver is often used as a solder for jewelry.
Jewelry melts at a high melting point, so a torch is usually used to solder the jewelry.
Flux is a type of soldering metal that is used as a catalyst for transferring heat to an iron so that the solder will chemically bond with the metals that are being soldered. Flux comes in different forms depending on what the needs are of the welder, such as gel, paste and liquid.
Most solder is not just one metal by itself but is a combination of different metals, usually tin and lead. As mentioned above, lead is usually avoided.
Instead, tin is usually used with small amounts of other metals mixed in. These types of solder work just as well as those with lead in them, except they are not as good at putting film over bronze.