I hate dealing with witch doctors but sometimes there is no alternative than you voodoo materials science folk.
What is a low cost (< $5/lb) light weight (< 2g/cc) material that remains a solid at 2200 F and can be spun into wool (d < .2mm) and is a more or less an ok conductor?
Stresses are minimal -- a gas moving at 1 meter per second.
"Down in Loosiana where the black trees grow lived a voodoo woman named Marie . . ."