Originally Posted by mattathayde
i would think you have a large chance for issues not guaranteed but a chance. if you use a traditional wax that just builds up a layer but some of the spiffy new stuff i wouldnt try. car wax is meant to go on top of paint and clear coat which wont react like bare metals will. Johnson's floor wax (in the yellow can with the red stripe) is safe and good (we use it on the jewelry/small scale metal work we do at school to protect and lock in the patina). if you let your copper/brass patina to a level you like and then wax it the ptina will stay at that level too
Its good to have a metal expert here on the forum, lol!