Overglaze vs Super spray for Devitrification - WarmGlass.com

Overglaze vs Super spray for Devitrification

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tgotch
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Overglaze vs Super spray for Devitrification

Postby tgotch » Thu Oct 10, 2013 8:44 am

I sometimes get devitrification on bottles I slump and fuse. I have been using the recipe of borax and water. Seems to work ok, but thinner and brown glass is more prone to devit it seems.

I have been hearing reading about Super Spray A and Clear Coat Overglaze. It's my understanding that the Warm Glass recipe with Borax is essentially the same as Super Spray. I also heard someone using Clear Coat Overglaze which they say helps control devit better. Any thoughts on Overglaze vs. Superspray vs. Borax recipe?

Barry Kaiser
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Re: Overglaze vs Super spray for Devitrification

Postby Barry Kaiser » Thu Oct 10, 2013 9:45 am

Clear Coat Overglaze is the same as borax based Devit agent.
Spray A contains low melt glass to prevent devit.

I use a home made borax agent. It is ultra-cheap and Works beautifully. I use it an all ground edges.

Someone else chime in here about bottles or found glass. That could well be a different situation.

Barry

Valerie Adams
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Re: Overglaze vs Super spray for Devitrification

Postby Valerie Adams » Thu Oct 10, 2013 10:12 am

I've had a strict 'no bottle slumping' rule in my studio for the past 13 years.

But recently, a very dear friend requested that I slump a special bottle. I swore her to secrecy, did a little research, sprayed it with SuperSpray, and flattened. The damn thing turned out so well that she sent me another bottle. I gritted my teeth and repeated the process, with great results. Spurred on, she then sent me an anniversary celebration champagne bottle with painted enamel flowers and gold accents. Once again, turned out perfectly. When she reminded me that she had connections with a large, local brewery and could 'hook you up as their bottle flattener' I put a stop to the nonsense, sending her to another studio. :twisted:

So, in my very limited experience, SuperSpray does what it says it'll do.

Judd
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Re: Overglaze vs Super spray for Devitrification

Postby Judd » Thu Oct 10, 2013 10:33 am

You're getting devit on brown glass? I get it on blue occasionally. Are you sure you're cleaning the bottles thoroughly?

tgotch
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Re: Overglaze vs Super spray for Devitrification

Postby tgotch » Thu Oct 10, 2013 11:15 am

I get all the label residue off the bottles, wash them, then wipe them thoroughly with 91% alcohol. They are spotless. I then spray with my borax mix(wipe it around with my finger or brush), dry, then put in kiln.

I haven't done much with blue bottles yet...

I have noticed green bottles almost always turn out great. I also have brown/amber bottles that are thick, and almost always turn out great. I have been slumping some thinner brown/amber wine bottles, and have been experiencing ~40-50% of the bottles have devit, many times near the bottom. This same color bottle with thicker walled glass as I mentioned does not get devit, but the thinner does...

Judd
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Re: Overglaze vs Super spray for Devitrification

Postby Judd » Fri Oct 11, 2013 10:15 am

Are you firing too hot or too long? Just a thought.

tgotch
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Re: Overglaze vs Super spray for Devitrification

Postby tgotch » Fri Oct 11, 2013 8:09 pm

Judd wrote:Are you firing too hot or too long? Just a thought.

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rosanna gusler
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Re: Overglaze vs Super spray for Devitrification

Postby rosanna gusler » Sun Oct 13, 2013 12:11 pm

i find that most devit problems can be eliminayed by venting to 1000f. i hold for 20 or so there as well. r.
artist, owner of wanchese art studio, marine finisher

Peter Angel
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Re: Overglaze vs Super spray for Devitrification

Postby Peter Angel » Sun Oct 13, 2013 5:29 pm

rosanna gusler wrote:i find that most devit problems can be eliminayed by venting to 1000f. i hold for 20 or so there as well. r.


Thanks Rosanna.

Just curious - What happens at 1000F that requires venting?
Peter Angel
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A bigger kiln, A bigger kiln, my kingdom for a bigger kiln.

rosanna gusler
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Re: Overglaze vs Super spray for Devitrification

Postby rosanna gusler » Sun Oct 13, 2013 9:57 pm

Venting the kiln while heating lets out the 'fumes ' from anything organic out. Holding makes sure the whole kiln is up to temp. R.
artist, owner of wanchese art studio, marine finisher


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