Whether they're made of metal, ceramic or wood, the life of the chimes on a wind chime is usually longer than that of its strings. Periodically, you'll likely need to restring your favourite wind chime in order to keep it in working order. This process may involve minor repairs of the chimes themselves, as well as careful measuring and cutting of the string to ensure that the chimes hang and ring the way they're supposed to.
Remove and set aside all portions of the chime that have frayed string. Snip away the bits of old string and discard. If any chime pieces have broken parts that prevent them from being hung, set these aside for repair.
Mix the epoxy putty according to the manufacturer's instructions. While wearing rubber gloves, use the putty to re-form the broken parts of the wind chime pieces or to build an extension piece on top of the chime. Poke a hole through the putty with a large sewing needle before letting it cure to hardness, according to manufacturer's instructions.
Restring the top of the wind chime with fishing line, if necessary, and hang it up near your workstation, in a spot you can easily reach and access it while you fix the rest. This will allow you to gauge the heights of the pieces as you tie them back in place.
String the removed chimes and repaired chimes with lengths of fishing line. Leave the lengths of line untied and cut each one about 4 inches longer than you estimate you'll need; this will give you some space to adjust the length when you hang them.
Hang the chimes. Tie them off at the lengths you want with a double knot according to where the chimes hang. Wet the ends of the line as you tie; this will help the fishing line stick to itself and make the knots more secure. Trim excess line from each knot. Leave about 1/2-inch "tail" on each string to prevent unravelling later.