Hi, I am having trouble with large bubbles… I am frit painting and hate ruining a piece. I fire system 96 as recommended with a longer squeeze time of 1hour at 1156. Ramp of 300/hr. I fire to contour fuse of 1455. Size of piece: 1 standard layer of clear, with frit, 12″x9″ with a sheet of thin fire on the kiln shelf. The shelf has a coating as well for safety sake. Some of the pieces are fine but some come out with a fist size bubble in the center! All of the smaller ones are fine. Help! I tried adding a sprinkle of clear med frit under the edges and having a longer soak time. Some work but then one won’t! What else can I try? I can flip it over and refire with frit in the hole and sometimes save it. Sometimes it saves but I get another hole somewhere else. Now what? I wondered if a thicker fiber paper? Or maybe a layer of clear fine frit under the whole thing. The shelf is less than a year old and pretty smooth. I would appreciate some advise. donna
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