While some people love the look of new brass, others prefer the subtle colour change it takes on with age. Over time, brass will age on its own with exposure to air but you may not want to wait. Taking matters into your own hands, brass can be aged in a fraction of the time it would take for it to happen on its own.
Boil the chain in a solution of 1 tbsp of baking soda and a quart of water. This will help to remove the lacquer, making it easier to age the chain.
Allow the chain to boil in the solution for 15 to 20 minutes.
Remove the chain from the water carefully with tongs and rinse it under warm running water in the sink.
Once the chain is cool enough to touch, apply nail polish remover with acetone to a clean cloth and wipe away any excess lacquer from the chain.
Mix 1 part sea salt with 3 parts dark cider vinegar in a bowl.
Place the chain into the solution, making sure that it is completely submerged.
Allow the chain to soak in the solution for at least an hour.
Remove the chain from the solution and hold it over the sink to eliminate excess moisture.
Place the chain on a baking tray and put it into the oven at 232 degrees Cor 15 to 20 minutes, checking on it periodically. After the time has elapsed, check the colour. If you're looking for a darker colour, soak the chain again and put it back in the oven. Repeat soaking and baking until the desired colour is reached.
Set the chain aside and allow it to cool until it can be handled comfortably.
Polish the chain with a high-quality car wax such as Turtle Wax per the manufacturer's instructions.
Buff the chain with a clean dry cloth to restore the shine.