People collect individual charms that are meaningful to them. Charms are often given as gifts. If you collect or receive charms as gifts then its very important to you that you not loose even one of them. To protect your charms while wearing them on a bracelet the best line of defence is to solder each charm permanently to the bracelet.
Protect each charm from the heat of the soldering torch by encasing them in soldering insulation. This is a putty-like, reusable material that the charm can be encased in and protects up to 1649 degrees Celsius. Remove the material after the jump ring has been successfully soldered.
Look closely at the jump rings you wish to solder. Make sure that where they are slit the two ends butt up against one another perfectly. If you can't see with the naked eye, use a magnifying glass.
Soldering copper or brass jump rings can be done with solder and flux purchased at the hardware store. Soldering sterling silver requires solder and flux formulated specifically for sterling silver. Purchase it from a fine jewellery making supply house.
Bend open the jump ring with a needle nose pliers. Clean the two ends by lightly sanding them with fine Emory paper or use a fine jeweller's file.
Slip the jump ring around one link of the bracelet and slip the charm on to the jump ring too. Close the jump ring using the needle nose pliers and make sure the two ends butt up tightly against one another. If the butt joint isn't tight the solder will not be able to permanently fuse the joint.
Position the bracelet, charm and jump ring on a fireproof magnesium block. Make sure the butt joint of the jump ring is facing up.
With a clean, small artist's paint brush, paint liquid flux on the butt joint of the sterling silver jump ring. Place a tiny snippet of sterling silver solder over the butt joint. If soldering brass or copper, dab a dot of paste flux on to the butt joint using the tip of a wooden skewer. Snip off a dot of common wire solder and push it into the paste flux positioning it over the butt joint.
Light the torch and dial back the flame so the pressure is low. The hottest part of the flame is just beyond the blue tip of the flame. Heat the jump ring by slowly moving in towards it. Continue to heat the jump ring until the solder melts and flows.
Turn off the torch as soon as the solder has melted and flowed. Leave the bracelet to cool slowly. Pick up the cooled bracelet. Use fine steel wool to buff away any residue that might have been left on the jump ring. If the solder isn't perfectly smooth file it down with a fine jeweller's file.
The solder will ball up and turn a glossy silver just before it melts and flows.