Very new to metal working so please guide me if this sounds stupid or I sound like I have no clue what I'm talking about (this is the case, this is all very very foreign to me)   I welded a metal box 9x12x15 Tomorrow when I get all the lining stuff I will begin the following. two one inch layers of inswool coat with Instuff Ceramic-Fiber Rigidizer add a layer of Satanite Refractory Mortar coat with ITC-100 Refractory Coating then a layer of bubble alumina