I was told when I got my kiln to leave the top hole open when I fired to cone 04. I did a test to see if the kiln would fire to cone 5, and according to my records, an empty kiln turned on high took about 3 1/2 hours until the kiln sitter fell.
Now I'm going to fire a cone 5 load, and I am wondering if I should close the top hole also. The kiln is well vented, and the work is dry. I did 1 hour on low, 1 hour on medium with the lid open about 5 inches. Now the lid is closed and two of the three side holes are closed. Would closing the top hole heat the pieces more quickly? Would that be a good thing or not? I'm using Amoco Potter's Choice cone 5 glazes on Little Loafers. I'm not sure how long this cone 5 load will take, but the 04 loads take about 2 1/2 hours after I have turned the kiln to high. I'm not sure how long to set the sitter for. Any help is appreciated. Thank you.