by gibson » 16 Aug 2012 17:56
if you're talking about brass locks, try placing it in ketchup! no kidding - just let it sit for about an hour, and it takes the corrosion off. you can then rinse with water, and clean it with a brush. if the lock is disassembled you can soak the pieces in a mix of a tablespoon of salt, and a tablespoon of vinegar dissolved in about 750ml of hot water. leave it for about 45 minutes, and then brush off the tarnish. use a nylon brush, or an old toothbrush. these techniques also work with old keys that have been lying around and have turned brown with age. i use these techniques on old telegraph keys that i collect, and they work great!