I have just finished constructing a keg fridge, and now turning my attention to a converting a cooler to connect to a keg. I was just planning on running the beer through a coil of line inside an ice filled cooler, and mounting a tap to the side of the cooler. I have all of the parts except I am not sure of the line that I should run inside of the cooler. Obviously it needs to be metal so that the ice can be used to chill the beer passing through the line, but does anyone know if copper tubing is OK? If so, how long should the line be? Does anyone have suggestions or tips?