I was waiting for a consultation before posting a reply:
All together, your piece on this firing is about 32mm, or 1.25 inches thick. Because the thickness is uneven, you need to anneal for twice the thickness of an uniformly thick piece. Therefore, you need to anneal for a 64mm, or 2.5" thick piece.
Here is a screen capture of the portion of the chart "Annealing for Thick Slabs" for your reference. The bottom row has the info you need for your piece.
You are suggesting the following cycle:
ramp hold temp
250 20 1000
250 30 1150
50 85 1250
100 5 1300 (or whatever temp visually appears to achieve tack fuse)
Full 4 hrs 900
27 0 800
49 0 700
162 0 70
According to this chart, and the video cycles, you could use this cycle:
41/hour to 1000, hold for 20 (That is the cooling rate for twice the thickness of the one-inch slab by itself.)
600/hour to 1250, hold for 10 minutes or when you can visually confirm that the glass has softened enough
AFAP to 900 (Keep door closed--no peeking!)
4.3/hour to 800
8/hour to 700
26/hour to 70
This will take about 70 hours. It is a conservative schedule.
Mary Kay Nitchie
Bullseye Glass Co.
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