Thad E Ginathom
Well-Known Member
Mica is not a bad conductor of heat and leather would get charred and would eventually fall apart. The best spacers would be either ceramic or asbestos.

Please do not work with asbestos in any form. It is just too dangerous. Much of the world acknowledges this, but India does not yet. Yes, there are relatively safe compositions, but relatively is not safe enough. Many of the world's insurance companies wish it had never been discovered.