Soldering your electric guitar is a fun way to personalise your instrument, but making good solder connections takes some practice. Cleaning up your volume pots can have a small effect on the strength of your output signal and your guitar's tone. Some famous guitarists even like to solder their pickups with only minimal connections to get a beefier tone. Cleaning solder is not part of your instrument's regular maintenance and generally only needs to be done while you're changing pickups or your wiring.
Unscrew and remove the plastic back panel (or the pick guard on some instruments) that covers your guitar's electronics. If possible, take off the plastic volume and tone knobs and unscrew their mounting rings. Gently pull and push the pots out of the guitar's cavity so you have more room to work on them.
Heat your soldering iron and wipe the tip off on a spare piece of metal. Excess solder from the iron can easily get on your guitar pots while you're working and give you even more cleanup work to do.
Place the iron tip between the wire and the volume pot. Hold it in place for five to 10 seconds while the connection heats. Pull the wire away as soon as the solder connection melts.
Use a small piece of spare metal to scrape the excess solder from the volume pot. Reapply heat to the pot as needed if the solder stiffens too much. Take care not to apply too much pressure to the rings on your volume pots because you can bend them.
Use a solder suction tool for precision jobs or work on vintage instruments. Heat the solder as normal and then use the vacuum tool to remove it completely.
When working on a semi-hollow or completely hollow body, tie string around the threads of the volume pot shafts. Now you can loosen them and remove the pots from the guitar body and simply pull the strings to get them back inside. Since volume and tone pots are almost exactly the same, you can use the same method for your other pots.
Don't use a soldering iron with a large bit as it can overheat your volume pots and damage them. Always solder in a well-ventilated room and avoid breathing the solder fumes. Be careful not to remove the solder that holds a capacitor to your volume pots, as this could result in a drastic or unwanted change to your guitar's tone.