Remove the lid from the 5 gallon bucket. Pour 1 inch of clear ammonia into the bottom of the bucket. Be careful not to splash the liquid onto the sides of the container.
Place the 2 wooden blocks gently into the ammonia in the bucket. Arrange the blocks so that one end of each is facing the center of the bucket and the opposite ends radiate out towards the outer walls.
Set the plywood on top of the wooden blocks. Place your hinges onto the plywood. Snap the lid of the bucket securely in place. Check your hinges daily to see the progression of the patina developing on the brass.
Remove the hinges from the bucket once they have achieved the desired appearance. Dispose of the ammonia and bucket in a safe and legal manner once your project is complete.