Cold Heat Soldering (coldheat.com) I have one of these and want to
know if I can use it with sterling silver to close jump rings?? IF
yes, do I need to use a certain kind of solder?
The answer is 'Yes you can'.
But the real answer is "NO you should not'.
The solder used with electric soldering irons is a base metal, used
to be mostly lead, now it's tin or some other metal. This does a
number of things to precious metals. It contaminates the precious
metal. It probably will reduce the precious metal content in the
finished piece so that it can no longer be stamped or sold as
sterling. When polished, the solder joints will probably be
The solders used with precious metals are usually made from mostly
the metal they're being used on. The problems listed above don't
exist. However, they present one problem the soft solders (those that
melt around 500F) don't They require about 1200F to melt. This
requires the use of a torch.
For closing jump rings, a small butane fueled torch & paste solder
works well. If you've got unlimited funds to spend, a pulse arc
welder or a laser welder also will work, no solder needed.