SOLDER - WHY DIFFERENT ONES
60/40
60/40 solder is 60% tin and 40% lead. It stays in liquid stage longer, giving you more time to set a smooth bead. It melts at 372 to 374 degrees F. It solidifies at 361 degrees F. This is the most popular solder. Easy to use, consistent, smooth. 60/40 takes all patina great.
https://www.stainedglassexpress.com/60-40-solder-1-lb.html
50/50
50/50 solder is 50% tin and 50% lead. It is more economical than 60/40. It has a higher melting point of 413 to 420 degrees F. It solidifies at 361 degrees F.
https://www.stainedglassexpress.com/solder-50-50-1-lb.html
60/37
Fast setting or also called eutectic, which means it melts and solidifies at the same temperature. That means it stays where you put it. Great for decorative soldering. The melting temp is 361 degrees F.
https://www.stainedglassexpress.com/63-37-solder-1-lb.html
Lead Free - Do not be fooled. Lead certainly is the most toxic of the metals in solder. However, right behind lead is silver and antimony. Lead free melts at a higher temperature than lead solders which makes it more difficult to work with. Depending on the brand or type, the melting range is from 440 degrees to 482 degrees F. It is the least toxic of all the solders and should be used when making anything that will be in contact with the skin or handled often like jewelry, jewelry box or kaleidoscopes. Black patina works fine on lead free solder but copper patina does not. Some brands of lead free solder will have a satin finish, not the bright and shiny finish that most want. Amerway's Ruby and Emerald lead free solder do have the silver look.
https://www.stainedglassexpress.com/lead-free-solder-1-lb.html