I did a single layer plate firing which I have done many time’s before and it now has a big air bubble in it . I have not used my kiln for about 9 months, could this make a difference? I have a Jen Air and I fired it at:
300 1210 30
600 1400 10
Full 960 40
100 800 0
Can I do anything to save this piece? Like refiring it?