Fusing went funky

[Dee Newbery]

I'm stumped. Have been trying different fusing schedules with my new kiln and am beginning to feel I don't know anything about fusing. I've had some real unhappy results.
The latest:
A elongated, rectangle 14" long, 4 1/4" at one end and 6 1/2" at the other.
It's a mask comprised of a clear dbl rl base, with interlocking pieces of opal on top, and additional pieces of opal, confetti, rod, stringer and frit sprinkled about. I fused this using the schedule below which I thought was slow enough to eliminate any bubbles. However, the face looks like it has pimples everywhere there is the single layer of opal.
This is all BE glass fired on thin fire shelf paper.
Can anyone suggest what happened? Also is it possible to refuse this to get rid of the pimples, if so what temps, etc?

400 dpm to 1180 - soak 30min
500 dpm to 1450 - soak 0
9999 to 960 - soak 1 hr.
210 dpm to 750 - soak 0
9999 to 80 - soak 0

another question - everyone talks about watching and checking the glass fuse and/or slump. How do you do that - don't you risk thermal shock when you open the door even briefly?
D

[Cynthia]

I'm stumped. Have been trying different fusing schedules with my new kiln and am beginning to feel I don't know anything about fusing. I've had some real unhappy results.
The latest:
A elongated, rectangle 14" long, 4 1/4" at one end and 6 1/2" at the other.
It's a mask comprised of a clear dbl rl base, with interlocking pieces of opal on top, and additional pieces of opal, confetti, rod, stringer and frit sprinkled about. I fused this using the schedule below which I thought was slow enough to eliminate any bubbles. However, the face looks like it has pimples everywhere there is the single layer of opal.
This is all BE glass fired on thin fire shelf paper.
Can anyone suggest what happened? Also is it possible to refuse this to get rid of the pimples, if so what temps, etc?

400 dpm to 1180 - soak 30min
500 dpm to 1450 - soak 0
9999 to 960 - soak 1 hr.
210 dpm to 750 - soak 0
9999 to 80 - soak 0

another question - everyone talks about watching and checking the glass fuse and/or slump. How do you do that - don't you risk thermal shock when you open the door even briefly?
D

Assuming your frit and stringers are on top and not sandwiched, I'd say your schedule is a good bubble reducing schedule. I ramp up to 1150 with no soak and then creep up to 1250 at 60 -100 dph, then ramp at 500 dph to full fuse. Best bubble reducing schedule I've got. Learned it from a post by Lynne Chappell.

If I misunderstood, and you sandwiched some glass bits between the base and the top, then your pimples are from the air you trapped.

As far as losing the acne...I've never had much success (with glass or skin ), but search the archives because I recall reading that a second firing has reduced the size for some...I just don't know the schedule.

You risk thermal shocking the glass at temps below 1000F. If you peek above that temp, your glass will be fine...but no peeking at lower than that 'til it's cool.

[Strega]

I just went and looked at all my irid pieces. I do a lot of irid with frit, and am not careful at all with temps and times because my kiln is 25 years old with no computer, so I just ramp up to 1500 and bake til done like cookies I can peak inside because I have peepholes. I get some surface bubble craters, that to me just look like "hey this is melted glass."
But I looked at a piece I did last night with gold BE rainbow on the bottom and orange on the top with chunks of other colors. The thing is full of trapped bubbles on one half. None of my other pieces have this. my partner, who is a glass blower and all round science guy, said that to him it looks, not like the air trapped between layers and frit, which is the usual case with bubbles, but like it came all the way up from the bottom surface of the irid. Trapped air between the irid and the shelf.
So I'm thinkin' the surface of the irid glass is rough. That's how it reflects light the way it does. But it didn't do this on the other pieces which are other colors, even the big bowl I did that was a sandwitch of purple opal and white opal. Maybe this is batch specific?
Maybe you should call up/email Bullseye....

[Dani]

But first, offer a tube of Persagel to the kiln gods instead of the requisite glass of wine. Maybe they're having a bad skin day. Hey, it can happen!!

[charlie]

But I looked at a piece I did last night with gold BE rainbow on the bottom and orange on the top with chunks of other colors. The thing is full of trapped bubbles on one half. None of my other pieces have this. my partner, who is a glass blower and all round science guy, said that to him it looks, not like the air trapped between layers and frit, which is the usual case with bubbles, but like it came all the way up from the bottom surface of the irid. Trapped air between the irid and the shelf.
So I'm thinkin' the surface of the irid glass is rough. That's how it reflects light the way it does. But it didn't do this on the other pieces which are other colors, even the big bowl I did that was a sandwitch of purple opal and white opal. Maybe this is batch specific?
Maybe you should call up/email Bullseye....

there's an old batch of be wash that can cause this. it's a chemical interaction between the irid and the wash that produces the gasses that cause the bubbles. it appears as a spongy effect on the irid side of the glass.

[gone]

But I looked at a piece I did last night with gold BE rainbow on the bottom and orange on the top with chunks of other colors. The thing is full of trapped bubbles on one half. None of my other pieces have this. my partner, who is a glass blower and all round science guy, said that to him it looks, not like the air trapped between layers and frit, which is the usual case with bubbles, but like it came all the way up from the bottom surface of the irid. Trapped air between the irid and the shelf.
So I'm thinkin' the surface of the irid glass is rough. That's how it reflects light the way it does. But it didn't do this on the other pieces which are other colors, even the big bowl I did that was a sandwitch of purple opal and white opal. Maybe this is batch specific?
Maybe you should call up/email Bullseye....

there's an old batch of be wash that can cause this. it's a chemical interaction between the irid and the wash that produces the gasses that cause the bubbles. it appears as a spongy effect on the irid side of the glass.

You can also get this with BE silver irrid and thinfire.

Els

[kelly alge]

Do you have photos of this? Is this really ugly, or could you use this as a design element? Is it possible to make it happen regularly?

full-of-questions-girl

[Strega]

Do you have photos of this? Is this really ugly, or could you use this as a design element? Is it possible to make it happen regularly?

full-of-questions-girl

I think it looks interesting in the piece I did--the bubbles didn't come to the surface but are trapped. However, it is currently flat; I am planning to "drop ring" it so the result might not be good. It's all an experiment.
Speaking of photos, I haven't gotten the hang of THAT yet...I want to post requesting help on that but don't know which bulletin board to use....

[kelly alge]

Well, you're further ahead than I am on the photos thing, I don't even know how to put the little box around someone else's reply to include in my post. I see all these buttons and my brain starts to shut down.

wish to be more techy someday!

[Dani]

Kelly, you have to start now or your baby will be telling you how to do this! Click the "quote" button in the top right corner of this post and say hi to me in the next post! Then figure out how to change the colors of the font and let me know....

[Strega]

Kelly, you have to start now or your baby will be telling you how to do this! Click the "quote" button in the top right corner of this post and say hi to me in the next post! Then figure out how to change the colors of the font and let me know....

You mean like this? Hmm, did it work?

[Lynne Chappell]

I use a lot of black and even little bubbles look really awful if they are raised on the surface. As well as going really slow from 1150 to 1250, I have found that I will have small "pimples" at 1450, but if I fire a little higher (to 1480) they somehow flatten out. It's like the glass levels out around the bubbles and it looks much better. This doesn't fix the BIG bubbles, just the slight irregularity in the surface from little bubbles. You might try refiring a little hotter and see if it works for you.

I look in my kiln all the time. You do need to be careful at lower (slumping) temperatures. In my Clamshell the whole kiln lifts up and the glass is really exposed to chill. I did crack one piece cause I couldn't see the other side of the form and had the lid open for a bit too long. I've never cracked one in the top loading kiln. But don't hold it open too long when you're only slumping. And I NEVER open the kiln under 1100F. Even if I heard the dreaded ping, I still wait until it gets up to 1100 before I peek in to see if I need to start all over.

[kelly alge]

Kelly, you have to start now or your baby will be telling you how to do this! Click the "quote" button in the top right corner of this post and say hi to me in the next post! Then figure out how to change the colors of the font and let me know....

Yikes, I'm doing it!woo hoo, is this 0124 red?

thanks Dani!