Solders-Silver Soldering-Custom Design Circuit
Board Electronic Pcb
"Hard soldering" or "silver soldering" is used to join precious and semi-precious metals such as gold, silver, brass, and copper. The solder is usually referred to as easy, medium, or hard. This refers to its melting temperature, not the strength of the joint. Extra-easy solder contains 56% silver and has a melting point of 1,145 °F (618 °C). Extra-hard solder has 80% silver and melts at 1,370 °F (740 °C). If multiple joints are needed, then the jeweler will start with hard or extra-hard solder and switch to lower-temperature solders for later joints.
Silver solder is absorbed by the surrounding metal, resulting in a joint that is actually stronger than the metal being joined. The metal being joined must be perfectly flush, as silver solder cannot normally be used as a filler and any gaps will remain.
Another difference between brazing and soldering is how the solder is applied. In brazing, one generally uses rods that are touched to the joint while being heated. With silver soldering, small pieces of solder wire are placed onto the metal prior to heating. A flux, often made of boric acid and denatured alcohol, is used to keep the metal and solder clean and to prevent the solder from moving before it melts.
When silver solder melts, it tends to flow towards the area of greatest heat. Jewelers can somewhat control the direction the solder moves by leading it with a torch; it will even run straight up along a seam.