Page 1 of 1
Shrinkage when fusing!
Posted: Fri Oct 10, 2003 8:46 am
by Lonman
Shrinkage when fusing???
I tack fused a piece yesterday, and when I took it out of the kiln, it had shrunk by about 1/4" width-wise. I have had similar problems with full fuse projects, but not tack fusing. What is happening? The program I used is-
500 dph to 250 for 10min
500 dph to 500 for 10 min
500 dph to 750 for 10 min
600 dph to 1250 for 20 min
600 dph to 1400 for 10 min
9999 dph to 1000 for 1 hr
200 dph to 970 for 1 hr
200 dph to 750 then off
Please enlighten me.
Posted: Fri Oct 10, 2003 8:59 am
by Lani McGregor
Lonman,
Every kiln fires differently, but in our Paragon GL24s, 1400F - depending on the rate of fire - is closer to full rather than a tack fuse.
How much your glass is pulling in also depends on how many layers you're starting with. A single layer of thin is going to shrink more at this temperature than two layers of 1/8 inch glass.
Also, you don't mention what glass you're using, not all glass has the same viscosity at the same temp. BE at 1400 looks a little different than Spectrum and a LOT different than Wasser. Even within glasses by the same manufacturer, some glass will shrink more at this temp and some less.
As usual, without more information, it's not possible to do much more than guess.
That's my guess. -L
Posted: Fri Oct 10, 2003 9:00 am
by vblue
Are you using one layer of glass or two? Usually shrinkage occurs when you have one layer or if the second layer doesn't completely cover the edges of the bottom layer.
Vernelle
Re: Shrinkage when fusing!
Posted: Mon Oct 13, 2003 5:09 am
by Brian and Jenny Blanthorn
Lonman wrote:Shrinkage when fusing???
I tack fused a piece yesterday, and when I took it out of the kiln, it had shrunk by about 1/4" width-wise. I have had similar problems with full fuse projects, but not tack fusing. What is happening? The program I used is-
500 dph to 250 for 10min
500 dph to 500 for 10 min
500 dph to 750 for 10 min
600 dph to 1250 for 20 min
600 dph to 1400 for 10 min
9999 dph to 1000 for 1 hr
200 dph to 970 for 1 hr
200 dph to 750 then off
Please enlighten me.
Glass thickness is related 2 temp
So if thin it will pool up in2 itself, but same glass thicker will pool out
Its surface tension
But take that thin glass n get it realy hot n it will pool out again
Brian