Loosening the strings of an electric guitar to clean the fretboard is generally considered safe, but there are some important precautions and guidelines to follow to prevent any potential damage to the guitar:
Loosen gradually: If you need to loosen the strings, do it gradually and not all at once. Loosening them suddenly can put extra stress on the neck and may cause it to warp or bend.
Do not remove all tension: While you can loosen the strings to make cleaning the fretboard easier, avoid detuning the guitar to the point where there is no tension on the neck. The neck of the guitar relies on the tension from the strings to maintain its proper curvature, and releasing all the tension can cause problems.
Support the neck: While cleaning the fretboard, it's a good idea to support the neck of the guitar to ensure it doesn't bend or warp while the strings are loosened. You can do this by placing a cushion or folded cloth under the neck while you work on the fretboard.
Use the right cleaning products: When cleaning the fretboard, use a specialized fretboard cleaner or a small amount of lemon oil (for certain types of fretboards like rosewood or ebony). Avoid using excessive moisture that could seep into the wood and cause damage.
Clean and oil frets individually: To avoid excessive moisture or cleaning solution on the fretboard, clean and oil one or a few frets at a time, then move to the next set. This way, you can focus on small areas and minimize any risk of damage.
Re-tune carefully: After you have cleaned the fretboard and re-strung the guitar, re-tune it slowly and gradually. This helps to minimize sudden tension changes on the neck and reduces the risk of damage.
Regular maintenance: Regularly clean your fretboard and keep your guitar in good condition to avoid having to make significant adjustments to the string tension. Routine maintenance will help keep your guitar playing and sounding its best.
If you're unsure about how to clean the fretboard or are concerned about potential damage to your guitar, it's always a good idea to take your instrument to a professional guitar technician. They can clean and maintain the fretboard properly while ensuring the guitar is set up correctly and remains in optimal playing condition.