An extreme temperature resistant felted material made of the highest quality pure carbon fiber for the lowest possible residual ash content. Ideal for use as part of fixtures or holders when working quartz or borosilicate under extreme heat conditions or when very close to molten glass. This material does not melt or burn even with direct molten glass contact. When in extreme heat conditions this remarkable material slowly sublimes directly from a solid to a gas: carbon dioxide. It does not melt but gradually evaporates leaving no residue behind. It is more fragile than and should not be confused with the felted natural fiber cooling pad.
For quartz work, there is no special cleanup necessary after use. Any stray residual fibers simply wash out or will evaporate when annealed.
For borosilicate work, you can easily apply your heat zone as close to the felt as you like. Be aware that even though molten glass does not stick to this, the glass will be textured by molten contact with the felt surface. There is no contaminant left on/in the molten glass; the only consequence is the texture imparted to the molten glass surface.
Under extreme heat conditions, it will gradually evaporate and should be considered a consumable supply that may need routine replacement. Interestingly these properties make it ideal for use as a sealed-in-place packing material when building multi walled objects. After construction is complete, simply run the glass through an annealing cycle with a very slow . 2 to .3 liter/minute stream of air or .1 to .2 Liter/minute oxygen fed into the object chamber containing the felt. Given sufficient exposure to oxygen while annealing, it will evaporate leaving no residue and no need for post anneal rinsing such as when burning out paper or cardboard.
It will tolerate temperatures far in excess of any metal holder and requires no dangerous acid cleanup with nitric acid or Aqua Regia such as when removing sealed in brass, copper, or stainless holders.