Looking for help in determining why
small lumps formed under irid fired up, details and pics follow:
Gold irid on black, alchemy glass and silver on tekta base
4 Squares, nearly identical, approx 8", lumps in all, evenly spaced filling shelf
Olympic clamshell, side with optional top firing 1-10 setting, set to 5
Trusted firing schedule pic attached
1) What kind of kiln shelf are you using?
18" kiln washed fiber on floor