Restringing looks like a job of strength; it is really a job of order. The same set of strings can be stage-ready the next day or still drifting after a week, and the difference is in a few details.
Check the string first. Guzheng strings are graded by pitch and gauge: bass strings are thick, treble thin. Fitted in the wrong position they will not reach pitch, or will snap as you tighten. Match the note name to the old string; if the old one broke and you have no reference, check the order against a chart (string types and replacement).
One string at a time. Slackening the whole set removes tension from the soundboard and frame at once, and both then have to settle again. Replacing one at a time keeps the instrument loaded and stable.
Slacken and remove. Turn the pin anticlockwise until the string has no tension, then draw the tail out of the pin hole. The old end whips back quickly — hold it as you pull.
Thread and coil. Pass the new string through the hole, leaving a short tail, and make the first turn of the coil trap that tail, then two or three more turns. A tail that is not trapped will slip under tension — the most common reason a freshly changed string suddenly drops pitch.
Tension in stages. Bring it roughly to pitch, pause, then raise it gradually. Taking it straight to pitch stretches a nylon-steel string thin and makes tuning less stable, not more. Seat the string properly in the nut and bridge notch as you go, and keep the strings from crossing.
Stretch and retune. Lift the string gently at its midpoint two or three times, then tune. New strings stretch: tuning once or twice a day for the first two days is normal (tuning stability after restringing). The tuning method itself is in tuning a guzheng.
Finishing. Leave one or two centimetres of tail before cutting; cut too short and it withdraws. Check that no bridge has been dragged out of position, then play a scale string by string. Even a full set is best changed one string at a time.
If a buzz remains, or a note will not press to pitch, start with finding the cause of a buzz. For strings or specifications, contact us.