If you play every day and use inexpensive strings, peeling can occur in new strings within a week. Steel strings are too strong for a classical guitar, but you can use extended-play coated or composite strings, which are stronger and last longer. Before coated strings are wound, a thin coating is applied to the wrap. Tone brightness is retained, and the strings have a smoother feel. In composite strings, only the first and second treble strings are made of traditional mono-filament nylon. The other four have a polymer core. If the nylon treble strings wear out before the others, they can be replaced individually. Composite strings stretch less, are easier to tune, and will last longer than normal strings.
Heavy fingering is poor technique in classical guitar playing. It causes rapid string deterioration and wears down the frets. Just a few hours of heavy fingering can cause the metal wrap of a string to peel. Use light fingering when you play. Practice applying the least amount of pressure when holding down the strings between the frets. A decrease in heavy fingering reduces string peeling, and your playing will sound more professional.
Wash and thoroughly dry your hands before you play. Use a small amount of hand sanitizer to remove any residual oil from your fingers. Oil builds up on the strings and causes corrosion. A sanitizer softens calluses and fingernails, reducing the possibility they will damage the strings.
After you play, clean each string with a soft cotton cloth. Perspiration contains salt, which corrodes the metal and dries out the nylon. Wiping down the strings each time you practice will prevent perspiration buildup that contributes to peeling. Once a week, apply a small amount of WD-40 to a microfiber cloth. Wipe off each individual string. Clean the underside of the strings beginning at the nut at the top of the neck. Lay the guitar on its back, and slide the cloth under the strings at the top of the neck. Gently pull up on the cloth, but make sure the strings remain seated in the grooves on the nut. Slowly slide the cloth toward the bridge, gently pulling up as you move it back and forth. Cleaning once a week keeps the strings lubricated, which helps prevent peeling.
All strings eventually need replacement, but don't replace them all at once. Remove and replace one string at a time. Strings pull a tension force of 75 to 90 pounds on the neck and sound board. Releasing all the tension at once traumatizes the guitar, causing a loss of volume and tone until the force returns to normal. It takes several hours for the force to equilibrate, and places unnecessary stress on the guitar and strings. (1)