I need to replace my outdoor tap and thought it would be a simple matter of sweating off the old one and sweating on the new one. But I can't get the old one off! I'm using a propane torch to heat it up and vice grips on the tap to twist it off but it just won't budge. Is it possible I am heating it up too much? There isn't enough copper pipe there to cut it and add the new tap to the newly cut end. Thanks all.