1. Discoloration: Bleach is a powerful oxidizing agent and can cause severe discoloration to the finish of the guitar. It could remove or fade the paint, lacquer, or any other finish that is applied to the instrument.
2. Structural Damage: Bleach can weaken the material structure of the guitar. Wood, which is usually used in guitar construction, contains lignin, which can be bleached. Prolonged exposure to bleach can compromise the structural integrity of the wood, causing it to weaken and become brittle.
3. Metal Corrosion: If the guitar has metal parts, like frets, screws, or bridge saddles, the bleach can cause oxidation and corrosion. Corrosion can damage the metal over time, impairing its function and aesthetics.
4. Damage to Electronic Components: If the guitar is an electric guitar, exposing the electronics to bleach may cause permanent damage to the capacitors, resistors, and other electronic components inside.
5. Odor: Bleach has a strong odor that can linger in the guitar's wood and materials for a long time, affecting the overall playing experience.
Overall, pouring bleach on a guitar is strongly discouraged as it may lead to permanent and irreversible damage to the instrument's appearance, materials, and functionality.