The skeleton key epitomizes antiques with locking mechanisms. Whether you use them for your grandmother's wardrobe or an antique case you have in your attic, skeleton keys have the same basic shape. As such, one skeleton key can open multiple locks. With the passage of time, however, old skeleton key locks can freeze up and begin to fail. Fortunately, you can get your antique skeleton key lock working just like new by using a lubricant that helps remove debris and loosens the lock's inner mechanics.
Remove the top cap of the bottled graphite and cut the top of the applicator to open the bottle. Cut near the top of the applicator to ensure you create a small opening. Skeleton key locks have small keyholes; you need a small applicator opening to fit the keyhole.
Turn the skeleton key lock so the keyhole faces the ceiling. Skip this step if you cannot turn the lock because it's attached to a larger antique or part of a larger antique.
Insert the applicator into the lock's keyhole, and squeeze the powdered graphite bottle at least two times. Hold the bottle so the applicator points toward the floor, either straight down or angled.
Insert your skeleton key into the lock, and attempt to open it several times. The movement of the key disturbs the powered graphite which, in turn, helps lubricates the lock's inner mechanics.
Continue your attempt to open the lock until successful. Stop when the lock opens with little effort. Add more powdered graphite if you continue to have problems.
Remove excess powered graphite with a clean rag.
Do not use liquid or gel lubricants in your skeleton key lock as these can attract more dirt, dust and debris that will exasperate your problem.