Huge craters in my fused panels
- March 29, 2011 at 1:40 pm #9617
I am fusing some glass panels about 18 in. X 16 in. X 1/4 in. All the glass is Spectrum 96 two layers thick with a small pattern on top of the two solid sheets.The first ten panels went fine. The last three ended up with silver dollar sized craters in them. I can accualy see all the way to the paper like there was never any glass there to begin with. A neat trick if thats what you set out to acomplish in the first place.The shelf is level, flat and free of voids. I dont use kiln wash, just thin fire paper.I have tried firing slow to fast with no change in the huge craters showing up.It seems that the gas causing the bubbles is coming from under the panel as it blows right through the color that is agianst the kiln shelf and leaves a big hole.I wish I could figure out how to attatch a pic of this problem I’m having. Any ideas on why the glass gods are not smiling down on me ?
Thanks in advance
Mike StevensMarch 29, 2011 at 9:20 pm #12012Stephen RichardParticipant
This sounds like it is coming from under the glass. The shelf may not be flat, there may be some small divots. In any case, the air is not able to travel out from under the glass in these areas. If all else fails, put 1/2 mm fibre paper down and then thinfire over it. This ensures the air can get out from under the glass.
Stephen RichardMarch 30, 2011 at 2:33 pm #12013
I will give that a try.
Thanks StephenApril 4, 2011 at 12:31 pm #12014artyglassParticipant
I to use spectrum 96 and have come across this mainly in black glass. There are a couple of things to prevent air getting trapped in larger panels the first one is to place small pieses of glass at intervals under the panel, so the glass is sitting up off the shelf. The other is to cut only the top layer of glass in half then half again. Both of these allow the gas to escape as the panels are large and the larger thay are the less chance the gas has to eacape. This works for me. Good luckApril 4, 2011 at 2:36 pm #12015
Problem solved. It seems the thin fire paper would trap the gasses under the panel so I put 1/32nd paper down first and then thin fire on top of that.
Thanks so much for your help,
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