Rigidizing fibreboard

[Michelle Schouten]

I’ve rigidized, fired and cemented a fibreboard in an effort to make a new kiln shelf for my 2417 Evenheat. Does anyone know what temp Celsius I need to fire the cemented fibreboard? I used QF 180 blue as the cement.
Thanks in anticipation

[Kevin Midgley]

to whatever burns the binders off. Depends on time and temperature etc. The binder is usually sugar in my experience.

[Brad Walker]

650 C should do it, but it wouldn't hurt to go to 800 C.

[Kevin Midgley]

I thought you were not to take boards and blankets to too high a temperature in burnout because of the risks of creating crystobalite. That is why the non specific temperature I posted. It depends hugely on the amount of binder used in the particular material. I once used some building a kiln and burned it out with so much smoke production I figured someone would call the fire department. The supplier apologized.

[Michelle Schouten]

Thanks guys. I went to 820 C before seeing the replies. The blue cement has turned white and all seems good. I now have a new, flat, bigger shelf on top of the old one.
Kevin, what is crystobalite?