A lubricating product like WD-40 will do the trick to stop that squeaky noise. You can also coat all exposed surfaces of your aluminum or metal outdoor funriture with a light layer of WD-40 to prevent tarnishing. A handy way to stop or prevent that annoying creaky noise is to use the same type of product that you use to stop a squeaky screen door. Spray the metal parts, or apply with a cloth, using a lubricating product like WD-40, especially on the hinges; it will also help deter tarnishing. Usually the squeaking is a result of the metal sliding against the metal. It would be a good idea to lubricate the areas that come into contact with each other. If you go to any hardware store they will be able to recommend a good product and tips to fix the glider.