Kilning is performed at a single temperature setting for 4 to 8 weeks. That is in the range of 122-130°F (50-54.4°C). Flue-curing is a different set of conditions, with the temp ramping upward over a 5 to 7 day period from about 98°F (~37°C) to a max of about 165°F (~74°C). [Poach 600 eggs at once!]
Most plastics (though not all) can perform adequately at kiln temps. Only some plastics will not degrade at the max flue-cure temp. If your intent is to use the "incubator" simply as a container within which your home-built heating temp control will operate for kilning, then that may work quite well, regardless of the insulating material. I doubt that the built-in controllers and heating system can be set to the required temp. BUT...you would need to inspect the detailed specifications of the manufacturer, in addition to inspecting the home-brew re-wiring performed by the seller's husband. With no manufacturer's labeling evident, you can't really look up specs on what materials the walls are made from.
So this may function as a kiln as is. More likely is that you will have to re-do the controls for tobacco kiln temps. There seems to be no way of determining if it would hold up to flue-curing.
Bob
www.trademe.co.nz
