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Question about annealing thick boro marbles

I always thought a 12-hour cycle in my Paragon was enough, but a cracked piece from last week proved me wrong. Has anyone else found they need longer for pieces over two inches?
3 comments

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3 Comments
evan_burns95
evan_burns951mo agoMost Upvoted
Hold up, are we sure the crack came from the annealing? I've done tons of big marbles in my old kiln with a 10 hour cycle and they're fine years later. Could be a stress point from the punty or a tiny bubble you didn't see. Sometimes we blame the kiln schedule when it's just a random flaw in the glass. I'd check your garage cooling too, maybe a draft hit it.
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palmer.richard
My last cracked marble definitely came from a punty mark, I was so mad! I spent two hours on the design and it popped right at the cold seal.
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harper_cooper21
Honestly, I get what you're saying about random flaws, but a 10 hour cycle for big marbles sounds way too fast to me. That's asking for trouble.
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