DIY Iron Furnace Build

I made a small furnace for casting iron and stainless steel. It uses the same burner as my aluminum furnace but takes about 2 hours to heat up( a .75GPH nozzle is in the mail). If you wanted to save fuel simply coating ceramic blanket in santanite or Itc-100 might be better. I wanted something more robust, the refractory is very heavy and rated to 3000F. I should be able to push it a bit but the crucible won't quite cut it. I'll likely need one that's rated higher and can be capped and flooded with argon.