So, I just recently bought a Vivi Nova and decided to rebuild all the heads myself, since I want to get the exact resistance I want for optimum voltage. I started to notice there was some sort of insulator material that I would put the wick into before sticking it inside the head. I just don't really know what kind of material it has and I'm afraid of burning it during the dry burn process. What kind of material is this? Is it resistant to heat? Can I dry-burn my Vivi Nova head without charring it?