I have read your Q and A on jumprings and it mentioned that "a jumpring is never truly closed unless you solder it closed." I would like to know how to solder a jumpring and what tools to use to do this. Can a soldering iron be used?
We can help you with the process of soldering solder filled jumprings; they have solder on one side of the opening. Attach the jumpring to where you need it. Close the ring completely so there is little to no gap. Using pliers, hold the jumpring in the air over a heat-protected work surface, with the opening facing downward, making sure that the attached items are out of the way.
Heat the opening of the jumpring, with a torch meant for soldering, or our micro-butane torch, so that the solder already inside the ring flows to fill the gap. Do not overheat or burn the solder away though. Once the solder is melted, it will fill the gap fairly quickly.
Please note that this takes a jeweler's torch to accomplish and we recommend taking a class or at the very least reading a book or tutorials regarding this technique so you are able to take the proper safety measures for your own protection.