I have a Sanyo 4912 (I think...it is the one everyone else is converting.) that I have been using for a couple of years with taps out the front door. I ran out of CO2 last friday night and brought my 20# welding tank in for temporary service. Rather than using my 5# tank in the keggerator, I would like to keep using the 20# tank as it is much more economical. I need to drill a hole through the right side of my keggerator in the top-back to keep the tank outside and run my CO2 line into the fridge. Has anyone done this? Is there a safe place to drill?