Heat Wrap ?

[vex]

I think a little clarification needs to be said in order to better understand:

Insulating Materials, 540*R
Blanket (Glass Fiber) Cp=--, Density=1.0 lb/ft^3, Thermal Conductivity = 0.027 btu/(h ft R)
Cork Cp=0.43, Density= 7.5 lb/ft^3, Thermal Conductivity = 0.023
Duct Liner (Glass Fiber, Coated) Cp= 0.199, Density = 2.0, Thermal Conductivity = 0.022
Polystyrene (extruded) Cp=0.289, Density = 3.34, Thermal Conductivity = 0.016
Vermiculite fill (flakes) Cp=0.199, Density = 5.0, Thermal Conductivity = 0.039

http://global.kyocera.com/fcworld/ch...ermalcond.html

Strictly speaking if you do ceramic you will get more insulation with less (depending on ceramic used), however defects in application and ensuring proper curing without cracking or removal of the ceramic is something else you'll need to consider.