Soldering is the process of joining two metal pipes together with a substance called solder.
It works by heating the two parts as they are held together and then adding solder that softens as it heats up. The solder will melt and in the process flow into the gap between the two pipes, creating an airtight joint.
Soldering can refer to both soft soldering and hard soldering. The differences between the two lie in the type of solder used to join the materials and the temperatures required to melt them.
Soldering and soldering rods are pieces of metal alloys whose melting point is lower than that of the metals to be joined. Brazing or brazing alloys are made from alloys containing silver, copper, or nickel that have a melting point above 450 degrees Celsius (842 degrees Fahrenheit).
On the other hand, solder wire is made from a combination of zinc, copper, lead, bismuth and antimony or palladium. These metals have a melting point of 180 to 190 degrees Celsius (356 to 374 degrees Fahrenheit).
Lead-free solder must be used for plumbing work. Lead-free actually refers to solder that has a lead content of less than 0.2%, not lead-free at all. This is enough to prevent lead from entering the water.
