My first furnace is a little A5 sized, gas fired, one build to Anon's plans. Works great, within its size limitations.
I have some Calcium Silicate boards and wedges left over from insulating my kitchen and bathroom, and was wondering about their suitablity for insulation of the next furnace? Does anyone have any experience with this stuff as insulation? It is also used for industrial firproofing up to 1000°C (1832°F). Is is reasonable to expect it to survive behind a thin hotface in an oil fired, iron melting furnance?
I was thinking about cutting the boards into strips and arranging them for about 3 inchs of insulating wall, and then making a Mullite hot face out of plates using Anon's recipe, as that stuff is absolutely impervious to the temps up to iron.
Is still have some of 1" Kaowool left over. Would it be necessary to insulate the CalSil insulation from direct contact with the hot face?
Since my hotface cracked badly due to excessively fast firing in the little furnace, I'd prefire these hotface plates in a friends pottery oven. Its probably not hot enough to fully fire mullite, but can get then most of the way there, so they would hopefully survive furnace firing.