Dip soldering a small tank containing molten solder. PCB with mounted components is dipped manually into the tank when the molten solder sticks to the exposed metallic areas of the board. Dip soldering is accomplished by submerging parts to be joined into a molten solder bath. Thus, all components surfaces are coated with filler metal. Solders have low surface tension and high wetting capability. There are many types of solders, each used for different applications. Such as Lead-Silver for strength at higher than room temperature. Tin-Lead is used for General Purpose; Tin-Zinc is used for Aluminum; Cadmium-Silver is used for strength at
Group 11 element is used widely in mission-critical applications as electrical contacts, and is also used in photography (because silver nitrate reverts to metal on exposure to light), agriculture, medicine, audiophile and scientific applications. Gold, silver, and copper are quite soft metals and so are easily damaged in daily use as coins. Precious metal may also be easily abraded and worn away through use. In their numismatic functions these metals must be alloyed with other metals to afford coins greater durability. The alloying with other metals makes the resulting coins harder, less likely to become deformed and more resistant to wear. Gold coins: