Report Electric Bisque 06 in Studio Operations and Making Work Posted October 10, 2020 I've been firing with the lid open about 3" until 400F. The idea is to burn out the water and organics. Then close the lid and fire with the top plug out. I'm noticing pretty substantial corrosion on the one year old lid band from the exhaust out the top plug. I suspect something like sulphur burns out higher than 400. Yes? Best practice? What would be considered a safe ramp speed through quartz inversion? I'm talking max size the kiln will handle.