I have a carboy of wheat beer that I want to keg. I have all the equipment, but my CO2 tank is empty. Do I need to hook it up to pressurize the keg after I fill it, or can I just put in priming sugar, add the beer, and seal it up? I'd like to get it kegged today, but the LHBS is closed, so I can't get my tank filled. My next chance to do it will be Wednesday, when I plan to brew as well, but I'd rather get it done today and not have as much stuff to do all at once later. Thoughts?