Solder is the small piece of alloyed metal that is melted in order to fuse two other pieces of metal together. The place where the metals are fused by solder is called a joint. The solder metal is of a lower melting temperature than the two pieces it’s fusing. Solder comes in three types: hard, medium, and easy. All three types have different melting temperatures. Hard solder melts at a high temperature, medium melts at a lower temperature, easy melts at an even lower temperature.
Multiple solder joints in a piece of jewelry require multiple types of solder. You don’t want to remelt a joint you just soldered while you are in the process of soldering another joint. The different melting temperatures will keep you from reflowing a solder joint. The first joint requires hard solder, the second joint requires medium solder, the third and remaining joints require easy solder.
Hard, medium, and easy solder is available in gold and silver. Gold is available in different karats and is significantly more expensive than silver solder, especially in higher karats.
Gold and silver solders come in different flow temperatures. For silver there is Itt, melting point 1490 degrees F., Hard, 1425 degrees F., Medium, 1390 degrees F., Easy, 1325 degrees F., and Easy-flo, 1270 degrees F. Gold solders are usually a karat or two lower than the gold being soldered and also comes in Hard, Medium, and Easy solder.
The different flow temperatures makes it possible to do multiple soldering on a piece without the previous joints becoming unsoldered. The first join is made with Hard, the next with Medium, and the rest with Easy. I dont like to use Itt because it is too close to the melting point of silver. With an oxy/acetylene unit it takes less than a second of inattention to melt your piece. Easy-flo has cadmium in it which gives off poisonous fumes when heated. Make sure your work area is well ventilated.
Solder comes in sheet, wire and paste. Sheet solder is cut into papillons, which is a French word meaning little tiny pieces of metal that fly all over the place while youre cutting them.
Paste solder comes in a syringe type applicator and is premixed with flux. I find that the flux to solder mixture varies depending on how long its been sitting since it was made. For best results it is better to empty the applicator, mix up the paste thoroughly and put it back into the applicator or in a small, lidded glass container.
I prefer wire solder, I can flatten it to cut tiny pieces or just cut a piece off the end of the coil. You want to use just enough solder to make a good strong joint without flooding the joint. Nothing looks worse than a joint with blobs of solder on it. Besides, it will take you longer to clean up the joint.
Solder comes in different forms:
- Sheets of silver and gold solder are available in hard, medium, and easy. You can trim the sheets to smaller pieces (papillons) to fit your needs. Hard solder is slightly more expensive than medium or easy. Thicker sheets will be more expensive. Many jewelers like cutting custom-sized, smaller pieces from sheet solder. Amazon offers silver solder in hard, medium, and easy on their website. Rio Grande offers gold solder in hard, medium, and easy in 8, 10, 14, 18, and 22 karat gold.
- Wire of silver and gold solder is also available in hard, medium, and easy. Wire comes in different gauges (thicknesses) with thicker gauges being more expensive. It is sold by length in feet. Many jewelers prefer the heft of wire solder rather than the thinness of sheet solder. Amazon offers silver solder in hard, medium, and easy. Rio Grande offers gold solder in easy in 8, 10 and 14 karat gold.
Cut a solder piece that is large enough to fuse the joint, but not so large that it floods the joint. Too much solder leads to many hours of clean up in order to create a seamless solder joint.
Avoid any solder that contains the metal cadmium. It is toxic when heated.