Soldering is a relatively simple and inexpensive method for joining metal pipes, wiring, and sheets. Although a well soldered joint should last indefinitely, it can be opened without damage to its parts by heating it to the solder's melting point which is 360-460 degrees. This cannot be done with welded joints. The two secrets of soldering are to clean the joint thoroughly and to heat the work, not just the solder. The choice of proper solder and flux is also important.
Common solder is a mixture of tin and lead.
Flux is used to clean the metal surfaces to be joined, to prevent oxidation of the metal when it is heated, and to lower the surface tension of the molten solder so that it spreads and penetrates more readily. Several types of flux are available in liquid or paste form. Flux-core solders are also available, and they eliminate a separate fluxing step when soldering small objects. Successful soldering requires just enough heat to melt the solder. The work should be held by wooden clamps, clothes pins, or vise jaws.