morph tube furnace into vitrigraph kiln

[blenderbender]

Howdy... I need some help understanding what is probably pretty basic stuff revolving around kiln design. I scrounged an old tube furnace which had burned out elements that I'm trying to replace & modify into a vitrigraph kiln of sorts. Basically it's an 18" high x 10" OD cylindrical furnace with a 3" ID ceramic cylindrical core which was spiraled around it's outer diameter with 0.259 ohm/ft. Kanthal A1 wire. It was rated at 220 V - 2500 w - 12 Amp maximum. It had 3 power cords (clipped off from quick uninstall) and appeared to be wired such that it had 3 different heat zones.... controlled by what I don't have a clue. There was no indication that any thermocouples were present, though on the outside of the cylinder core was an 18" long hollow ceramic tube buried lengthwise in the refractory cement that bedded the element wire. The tube's ID is about .120" and it was accessible through a hole in the top end furnace cap. My initial challenge is to figure out what gauge Kanthal wire to use. Based on the number of grooves in the core and it's circumference it is possible to get nearly 90 ft. around it. I understand Ohm's law to a degree but have no sense of the target I'm shooting for in terms of end power and heat output, if that makes sense. I likely can power it up with either 110v or 220v depending on how I choose to zone it. My initial thoughts are to split into at least 2 zones depending on the crucible height that is in the kiln. I still need to solve that puzzle cause there ain't no clay pots with less than 3" OD and any significant length. I was thinking of fabbing up some thin wall SS exhaust tubing into crucibles by adding an end cap. Any input is warmly welcome.... thanks, Gary

attempting to upload pics.... .... they got resized significantly but I think the visual information is there