extruding glass strands from pot

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roykirk
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Joined: Tue May 12, 2015 9:54 am

extruding glass strands from pot

Post by roykirk »

I want to attempt a glass extruding project and I thought I'd check here for advice to try to make sure it goes as smoothly as possible. Perhaps this technique has a name, and if it does I apologize for not knowing where to search before posting.

What I have is a small ceramic pot that I melted about a pound of glass in to. It melted and cooled perfectly without cracks to the glass or the ceramic pot. What I'd like to do now is fire up my kiln to glass melting temperature again, remove the pot from the kiln, and then use a steel rod to extrude several strands of glass while it cools (my completed vision being a pot of glass "exploding" like a fountain). The challenge being that I have a small front load kiln, so there's no way I can do this while the pot is still inside. I'm concerned that pulling it out, where it's going to start cooling rapidly, could cause the pot to shatter. Cracks I can deal with, but certainly don't want an explosion of superheated ceramic and molten glass.

So if anyone has tips like best temperature to use, or technique, I'd be happy to hear it.
The Hobbyist
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Re: extruding glass strands from pot

Post by The Hobbyist »

The name of the process is "vitrigraph" and I don't think it is possible with a front loading kiln.

I don't think you need fear the pot exploding. More likely it will cool rapidly past the point where any glass will flow. As it continues to cool it will begin to crack and break apart possibly with some force. I've only done something similar once (removing very hot glass from the kiln) and it was to crash a project that was failing. And I was only at temps in the 1200°F range. If I recall correctly, I/we pull vitrigraph strings at around 1900°F.

Toots Zinsky makes her own stringers, as you envision. I'm guessing the equipment would bankrupt most of us. There are some pics and maybe a video out there of her process. It is wonderful in its own right and then the stringers are used to make her signature pieces that are truly magnificent.

Bullseye and S96 make stringers in most colors of their product line. They're slightly pricy but actually cheap compared to the cost of making your own.

Jim "The Hobbyist"
"With or without religion, good people can behave well and bad people can do evil; but for good people to do evil—that takes religion. " Steven Weinberg
roykirk
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Joined: Tue May 12, 2015 9:54 am

Re: extruding glass strands from pot

Post by roykirk »

That's good info to know, thank you. It sounds like it'd be better to hold off on this project until I get a different kiln.
Marty
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Re: extruding glass strands from pot

Post by Marty »

I don't read the post as vitrigraph stuff- roykirk seems to me to be talking about having stuff come out of the pot as if the surface of the glass is exploding, like fireworks, no?
Lots of problems- first with pulling the pot out to draw glass from it (or lifting a kiln lid to get at the stuff), then with keeping the strands in place while they cool so they don't sag (while somehow keeping the pot temp steady for more pulls) and finally the annealing part. The strands will cool fast, the pot slowly, and the annealing temp will have to be a delicate balance to keep the strands from sagging. How big is this going to be?
roykirk
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Joined: Tue May 12, 2015 9:54 am

Re: extruding glass strands from pot

Post by roykirk »

The ceramic pot is about 3" in diameter and about 4" tall. I was thinking of trying to draw/pull strands out of it about 3" or so. I guess I was envisioning something like the following photo, just shorter strands and pulled out to the sides more (for the erupting effect):

https://i.pinimg.com/originals/a8/38/a4 ... a43de7.jpg
Marty
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Re: extruding glass strands from pot

Post by Marty »

Those were done individually on a punty (pontil) in a hot shop and then just grouped together for display. There are probably holes in the base for the glass which is most likely glued down.
I'd hate to have to ship that anywhere.
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