Report temp for opening kiln? in Studio Operations and Making Work Posted November 19, 2012 I high fire an earthenware clay (slipcasted). I open my top bung at 428F(220C), Front bung open at 392F (200C) and open door at 356F (180C). If I need to inspect a new piece, and I can get to it, I will remove it then. My friend works with porcelain. she opens her top bung at 572F (300C) No issues. Food safe , etc. Oh, and my friend can fire her kiln every 24 hours, should she want ... Quick ramp-up and down.