WarmGlass.com

Recently in another discussion Catharine mentioned that she had a piece that she had fired I think it was 17 times. I have often had pieces that I fired 5 or 6 times but never any more than that. I know that there are certain colors that can tend to change their COE after being taken to fusing temps again and again. I now have a piece that I have fired about 5 times and want to fire two more times. I'm getting a bit nervous about it because its relatively thick and I've never fired a thick piece so many times. Its BE black and white. I'm being very careful about very, very slow ramps up and down but do I have to worry about the COE changing after so many firings? I need an emoticon that shows nail biting...
-Amy

I may be wrong, but my understanding is that colors like red, yellow and orange are the ones that are susceptible to COE changes over multiple firings. I fire my "Firebird" series red, yellow and blue pieces 6 times and haven't ever experienced this. I also fire pieces in the same series in red, black and white 6 times and haven't experienced this either. I wouldn't worry about it. I've fired pieces in red, black and white at least 10 times before with no problems.

Geri

Amy on Salt Spring wrote:Recently in another discussion Catharine mentioned that she had a piece that she had fired I think it was 17 times. I have often had pieces that I fired 5 or 6 times but never any more than that. I know that there are certain colors that can tend to change their COE after being taken to fusing temps again and again. I now have a piece that I have fired about 5 times and want to fire two more times. I'm getting a bit nervous about it because its relatively thick and I've never fired a thick piece so many times. Its BE black and white. I'm being very careful about very, very slow ramps up and down but do I have to worry about the COE changing after so many firings? I need an emoticon that shows nail biting...
-Amy

If U keep the temp low then the problem of stuff comming out of the glass will B lessened

If using side elements then consider baffling the elements 2 avoid thermal shock

Brian

Amy,

I have fired panels 20 times with no ill effect... HOWEVER, the largest percentage of my firings are tack fusing. I probably only full fuse an entire piece 2-3 times in that 20. I don't think you'll have any problems with your next firing.

Catharine

I think the COE change is most pronounced in the red yellow oranges that strike. Something about the crystals building up and changing the COE. There was some discussion of this at Craftweb. B&W should be ok.

I think the shift could be a real issue. No-one tests their glass for more than 3 firings. There probably isn't a known definitive answer for this.