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First firing: Is this right?

Posted: Wed Apr 08, 2015 4:35 pm
by conboc
First Firing: Are these fully fused? When viewed from the top these look rounded but from at least two sides on most of these, the edges look like a sandwich. Is this a good firing?

Will fire polishing melt them together more? For my next try should I increase my fusing temperature, or the length of time? I used the standard Bullseye directions for fusing. Should I cut my top layer of clear glass slightly larger than the middle and bottom layer?
thanks.

thanks Brad. My kiln is a Paragon SC2. with a Sentry Xpress controller.

The firing schedule was
1 rate: 400 degrees, temp 1225 degrees, hold :60
2 rate: 600 degrees, temp 1490 degrees, hold :10
3 rate: FULL, temp 900 degrees, hold:1:00
4 Rate: 100 degrees, temp 700 degrees, hold :01
5 rate: FULL, temp 70 degrees, hold :00

firstfire.jpg

Re: First firing: Is this right?

Posted: Wed Apr 08, 2015 5:45 pm
by Brad Walker
What kind of kiln did you use? What firing schedule, specifically?

These are underfired for a full fuse and need to be fired higher than you did, but if you tell us a bit more about your kiln and schedule we can offer some very specific help.

Posted: Wed Apr 08, 2015 10:48 pm
by conboc
oops didn't realize i could add to the first post.

Re: First firing: Is this right?

Posted: Thu Apr 09, 2015 11:04 am
by Brad Walker
If you want a full fuse with rounded edges, the pieces are underfired. You can fire them again to get them more rounded. You have several options on how to do the second firing.

You could fire the same schedule, only slightly hotter.

You could fire the same schedule, only a longer hold at 1490.

You could go slower from 1225 to 1490. Firing around 200 dph (instead of 600) will give more time for heatwork and help round the pieces earlier.

With smaller kilns you often find that the standard schedules don't quite work and you need to fire hotter, hold longer, or go up slower after the bubble hold.

I prefer the third option, but any of the three will work. The key is to take notes of your firing and adjust based on what you learn. Each kiln is different, so you'll have to find the perfect schedules for your kiln.

Hope this helps.

Re: First firing: Is this right?

Posted: Thu Apr 09, 2015 11:26 am
by rosanna gusler
you can also grind the edges smooth and then fire polish. i like that look. r.

Re: First firing: Is this right?

Posted: Thu Apr 09, 2015 3:07 pm
by conboc
Brad, Thanks for your help. What would be your first guess for slightly hotter? 100 degrees hotter? or 200?

Thanks, too R for your experience.

Re: First firing: Is this right?

Posted: Thu Apr 09, 2015 4:20 pm
by Brad Walker
conboc wrote:Brad, Thanks for your help. What would be your first guess for slightly hotter? 100 degrees hotter? or 200?


Well, for a full fuse in my kilns I rarely go above 1500, and never above 1525. As I said, I prefer going slower from 1225 to the top temperature, rather than going hotter. But your kiln may be different. The best advice I can give you is to keep good notes and adjust based on what you learn from your firings.

I like Rosanna's suggestion, too. Straight edges can look really nice.

Re: First firing: Is this right?

Posted: Thu Apr 09, 2015 5:59 pm
by Morganica
As Rosanna said, it's a matter of preference--the nice thing about having your own kiln and making your own glasswork is that you get to dial in the textures, edge and shine you prefer, and it can be different for each firing.

Since you've recorded your firing schedule, also record the images and those three things, i.e., with that schedule and that particular layup of glass, the glass didn't completely fuse flat and round over--the texture of the individual components stayed distinct.

If you examine the pieces more closely, you'll notice that some of the colors of glass fused flatter and rounder than others; if you were to make pieces with only those colors, this schedule would probably be sufficient to give you a full, flat fuse. However, if you were to make up a piece of the "harder" glasses (the ones that stayed more textured), you'd need to apply more "heatwork," i.e., either fire longer/slower or higher or both, to achieve the same result.

If you keep gradually adjusting your schedules, and noting which glasses respond in different ways, you'll build up an arsenal of schedules for that kiln that will produce exactly the effect you want for a particular color/type of glass.

Re: First firing: Is this right?

Posted: Thu Apr 09, 2015 8:09 pm
by conboc
Thank you. Appreciate everyone's thoughts. Think i'll need a bigger notebook.
Ready to try again with a new firing schedule.
connie

Re: First firing: Is this right?

Posted: Fri Apr 10, 2015 12:50 am
by Kevin Midgley
Notebook?
Ha Ha Ha!
Try a bigger binder.

Re: First firing: Is this right?

Posted: Tue Apr 14, 2015 2:56 am
by Stereoette
I have 2 paragon kilns, and I have noticed that my SC2 actually fires about 50 degrees below the temperature on the display. You may need to fire higher on that particular kiln. Also, I find that my SC2 fires considerably cooler by the door, and requires a much longer soak to even things out.