Hi ceramic artists,
What causes white spots on bisque-fired brown stoneware clay? Will they disappear when I fire the piece to cone 5? (I initially intended to not glaze or stain it.)
I asked you about single-firing a sculpture about a week ago. Your answers were so helpful. I truly appreciated it. However, the ceramic studio did not allow me to single-fire my sculpture because the studio policy does not allow anyone to fire his/her piece alone. I just bisque-fired my work to cone 05. It might have been a good thing, as I noticed bothersome white areas here and there on the piece (the first photo below). Will they disappear when I fire it to cone 5? (It has to be fired with other studio participants' glazed pieces.)
I thought the white areas might be caused by hard water we have here. However, thrown pieces hardly have those. Some pieces have lots (like the cat in the second photo), and some have none (like the coiled one).
If you do not think white spots will disappear with mid-firing, I'm thinking of staining the sculpture with red iron oxide and then firing it to cone 5.
Thank you very much.