Help please! My first Devit experience....i think....

[Janz]

This is so ironic....I had just said last night how lucky I was that this had never happend to me.

Yesterday I fired a leaf between 2 scrap Sys. 96, and some dried flowers as well. I decided to throw in some regular Spectrum & Kokomo & Dragon Art scrap I had lying around to make some neat beads.
The leaf made a big crusty bubble, and the glass looks etched.... most of the "beads" look etched too....I don't know if this is devit. I've seen scummy looking stuff, but this looks and feels acid etched. It happend almost exclusivly to the opals.
Could this be burn off from the leaf? some gas or something? I left my peephole open. Or is this what major devit. looks like?
Thanks for any help.
Jan

[charlie]

regular spectrum and kokomo devit terribly, especially opals. i've had some kokomo literally fall apart into dust after firing, but it was a 4 color mixture. i haven't even had good luck with borax spray on regular spectrum.

[Bob]

Hi Janz,

Yup, it sounds like devitrification. Your observation that the scummy finish is most common on the opal glasses rings true. Opals are particularly prone to devit. Also, the chemistry of glasses made for fusing has been formaulated to minimize devitrification. If the Spectrum, Kokomo and other "scrap" glasses that you included are non fusing then they might be more prone to devitrification.

Cheers,

Bob

[lissa]

Do you prefer borax to super spray or the like? I understand how they work differently, I am just wondering why folks chose one over the other as the desired results are the same.

lissa.

[charlie]

Do you prefer borax to super spray or the like? I understand how they work differently, I am just wondering why folks chose one over the other as the desired results are the same.

lissa.

borax is cheap, i can buy a lifetime supply in one box in the supermarket, easy to mix and apply from a hand spray bottle, and doesn't have any lead.

[Janz]

Thanks....

I think they look pretty cool despite the devit.
They're gonna make some amazing mosaics one day.
If I ever get off all the kiln wash, that is.

Thanks again,
Jan

[Brian and Jenny Blanthorn]

This is so ironic....I had just said last night how lucky I was that this had never happend to me.

Yesterday I fired a leaf between 2 scrap Sys. 96, and some dried flowers as well. I decided to throw in some regular Spectrum & Kokomo & Dragon Art scrap I had lying around to make some neat beads.
The leaf made a big crusty bubble, and the glass looks etched.... most of the "beads" look etched too....I don't know if this is devit. I've seen scummy looking stuff, but this looks and feels acid etched. It happend almost exclusivly to the opals.
Could this be burn off from the leaf? some gas or something? I left my peephole open. Or is this what major devit. looks like?
Thanks for any help.
Jan

If U wana bit of fun U will find something about devit in the archives

In brief use some anti devit stuff

Keep temp low and creap up 2 temp

Or zap up fast n crash cool

There is lots more

Brian

[Joanne Owsley]

[quote="Bob"]Hi Janz,

Yup, it sounds like devitrification. Your observation that the scummy finish is most common on the opal glasses rings true. Opals are particularly prone to devit. Also, the chemistry of glasses made for fusing has been formaulated to minimize devitrification. If the Spectrum, Kokomo and other "scrap" glasses that you included are non fusing then they might be more prone to devitrification.

Cheers,

Bob[/quote]

I have experienced the "Opals are particualarly prone to devit" thing myself. I guess I just don't understand the chemistry of devitrification well enough though. How does having regular spectrum in the kiln with Sys 96 make the S96 devitrify? Is it kinda like making rock candy? Once the crystals start growing, they don't care what they grow on?

[Brian and Jenny Blanthorn]

Hi Janz,

Yup, it sounds like devitrification. Your observation that the scummy finish is most common on the opal glasses rings true. Opals are particularly prone to devit. Also, the chemistry of glasses made for fusing has been formaulated to minimize devitrification. If the Spectrum, Kokomo and other "scrap" glasses that you included are non fusing then they might be more prone to devitrification.

Cheers,

Bob

I have experienced the "Opals are particualarly prone to devit" thing myself. I guess I just don't understand the chemistry of devitrification well enough though. How does having regular spectrum in the kiln with Sys 96 make the S96 devitrify? Is it kinda like making rock candy? Once the crystals start growing, they don't care what they grow on?

Opals can have stuff in em which makes em opal the devit grows from this growth point is called a neucleation point

Brian

[Bob]

How does having regular spectrum in the kiln with Sys 96 make the S96 devitrify?

Hi Glasseyed,

The regular Spectrum is more prone to devitrifying than System 96. However having regular Spectrum in the kiln will not cause the System 96 devitrify. The devitrification is caused by the growth of microscopic crystals on the surface of the glass... this is dependant on the glass chemistry, temperature and time.

Cheers,

Bob

[Lynne Chappell]

Yes, but her System 96 pieces devitrified as well (I think). Could the burning leaf cause such problems?

[Janz]

The more I think about it, I don't think the leaf was responsible for any gas emission type stuff.... There's a huge bubble in the glass, if gas had esacped wouldn't the bubble have a hole, or something?