Thermal Shock? help…
Home › Forums › Glass Fusing › General Fusing Discussion › Thermal Shock? help…
- This topic has 4 replies, 3 voices, and was last updated 8 years, 10 months ago by FieryVisions.
- May 5, 2014 at 10:51 am #10147
I was just broken hearted when I opened kiln this morning to a totally ruined piece. Fused a 6×6 tile using this schedule:
300/hr 1100 .10
150/Hr 1240 .30
Full 1450 .15
Full. 980 .30
Full. 700 stop
Using 2 layers, 6mm coe90. I used a little cmc to hold pieces together. ONLY thing I can think is that atound 900 (on ramp up) I modded program to go a little higher on target temp…but kiln was only stopped for 30 secs at most. Could this have caused it? I thought my schedule was fairly conservative. Cant figure why this happened. Any help is appreciatedMay 5, 2014 at 9:00 pm #13358AnonymousInactive
If the broken edges are sharp (and I’m guessing they are) your piece broke on the way down. Full speed for annealing (980 – 700) is too fast.
Helios Kiln Glass Studio
PaulTarlow.comMay 6, 2014 at 12:11 am #13359
Thank you Paul! I had only done smaller pieces until now so it never effected them. I also thought that the long hold was sufficient. I appreciate the tip so if I slow to about 200 º /hr on the way down should that be slow enough?May 20, 2014 at 2:47 am #13360wordanaParticipant
Also, your annealing temp is too high. It is 950 for system 96, and I believe 900 for Bullseye 90 COE.
Between the incorrect temp and the quick schedule, you were never hitting the annealing zone long enough for the piece to anneal.
Jester’s Baubles Fused Glass DesignsMay 20, 2014 at 7:10 am #13361
Thanks so much Paul and Dana! Made corrections and had success
- You must be logged in to reply to this topic.