bubble problems

[Pam Damon]

Another problem with my beautiful blue/purple opal glass. I fused the broken cirlcle with cut out pieces of a large Kokopelli playing his flute to a dicro. moon. I filled in the broken line with frit. Well, it worked but needed to fill in one small point. I got the great idea to cap this baby with clear, what I got was one giant bubble at the edge of the moon. I fired 300dph to 1250 held for 3o minutes, AFAP to 1375 held for 1 hr. , ASAP to 960 hold for 30 minutes. My guess is I ramped to fast, didn't hold long enough.... and go big bubbles. My is how hig do I have to fire to break the bubble??? Or any other suggestions, please... Yes I have checked with the archives. Thanks in advance ,Pam,