Page 1 of 1

Crackling glass in kiln

Posted: Sat Aug 30, 2003 1:56 am
by Licha Ochoa Nicholson
Hi There,
I'm looking forward to a long holiday weekend spent in my studio just experimenting with techniques I've been wanting to execute for some time now. One technique I've been wanting to accomplish is crackling the glass in the kiln by spraying it with water. I've been told this can be done, however, I've had no luck so far. Has anyone done this technique? I need some help in figuring out at what temp will it crackle.
Thanks,
Licha

Posted: Sat Aug 30, 2003 1:05 pm
by Jack Bowman
I would say the temp is somewhere under 800F but not sure where is best. I think shattering would be the biggest problem.

Jack

Posted: Sat Aug 30, 2003 1:12 pm
by Dani
I would be too chicken to try and crackle my own glass. But, I've wondered what would happen if I tried to slump a piece of French Crackle. Has anyone tried it?

Posted: Sat Aug 30, 2003 9:34 pm
by Bert Weiss
Crackle is made by a glass blower dipping the bubble in to a tub of water. The glass which has only cooled on the surface is then put in the glory hole and reheated, but not hot enough to flow back together completely.

I would be pretty scared to work with water in an electric kiln that is in the 1400º or hotter zone.

Posted: Sat Aug 30, 2003 10:09 pm
by Barbara Muth
Hehe. Ask Brock about spritzing water in the kiln. Frankly Licha, I would stay away from attempting to do that in a kiln. Can you do it in a hot glass studio?

Alternatively, I have seen sheets fired in the kiln and dropped in a bucket of water to make frit. If there were some way you could reassemble that and fire it, you might get the crackle you are looking for without the water in the kiln.

Barbara

Posted: Sat Aug 30, 2003 11:08 pm
by Tony Smith
There are pictures in one of Lundstrom's book of this process. They pull the shelf out of the kiln at fusing temperature and move it away from the kiln, then they dump a bucket of water on it and put it back into the kiln to anneal.

I think it would be fun to watch... from afar.

Tony

Crackling glass in kiln

Posted: Sun Aug 31, 2003 12:56 am
by Licha Ochoa Nicholson
Hmmmm, all interesting viewpoints to take into consideration before I attempt this technique. Tony, your's was pretty interesting. Maybe I can remove a smaller kiln shelf from a hot box - maybe I'll borrow Patty's kiln ~ :lol:

Posted: Sun Aug 31, 2003 2:32 am
by Jack Bowman
Kirkland? Seems like I was just there. Is that right next to Redmond? Took a class at NW Artglass. Nice place, but I prefer rain once in a while.

Jack

Re: Crackling glass in kiln

Posted: Sun Aug 31, 2003 7:20 am
by Tony Smith
Licha wrote:Hmmmm, all interesting viewpoints to take into consideration before I attempt this technique. Tony, your's was pretty interesting. Maybe I can remove a smaller kiln shelf from a hot box - maybe I'll borrow Patty's kiln ~ :lol:
That wouls be an easy way to try it... use a hotbox, have someone lift it off (and back away) as "the artist formerly known as Licha" douses the piece with water. This could turn into a performance art piece.

I'll take a look to see which book it was in this morning.

Tony

Crackling glass in kiln

Posted: Sun Aug 31, 2003 1:48 pm
by Licha Ochoa Nicholson
Thanks all for your glass crackling info. Tony, I will try with a hotbox and let you know what turns out with this technique.
Thanks again.
Licha

Posted: Sun Aug 31, 2003 2:35 pm
by Tony Smith
According to Lundstrom's Glass Fusing Book 2, the glass was heated to 1550, removed from the kiln and had cold water poured over it. It was then flash fired to firepolish the edges of the fissures then crash cooled to 1300, then annealed as normal.

I've never tried this process, so I'm not sure how fast you have to move through the steps. Please be careful... steam burns can be nasty too.

Tony

Posted: Wed Sep 03, 2003 1:12 pm
by charlie
Tony Smith wrote:According to Lundstrom's Glass Fusing Book 2, the glass was heated to 1550, removed from the kiln and had cold water poured over it. It was then flash fired to firepolish the edges of the fissures then crash cooled to 1300, then annealed as normal.

I've never tried this process, so I'm not sure how fast you have to move through the steps. Please be careful... steam burns can be nasty too.

Tony
would a mullite kiln shelf survive this? i wonder if one would have to use a fiber shelf.

Posted: Wed Sep 03, 2003 1:20 pm
by Brock
I never had any luck with this technique. I poured water directly onto the piece in the kiln. Natural selection doesn't always work! As Bert says, it's the molten core of hot glass that keeps the piece together. A fused piece doesn't have a molten core. Brock

Posted: Wed Sep 03, 2003 2:03 pm
by Melodie
I’ve done this in the torch with beads and Bert is right, the core has to be molten. The outside crackles but the core stays hot enough that the glass doesn’t shatter apart. I was actually surprised at how long you could leave it in the water though. Then you pop it back in the torch to reheat the bead without sealing all the cracks. Makes a very cool bead but also a weak one.

I would think that this would have to be done very quickly for a fused piece since the inner temp would not be as hot. Seems like you would also need to be at least at a raking temp.

Melodie

Posted: Wed Sep 03, 2003 4:47 pm
by Licha Ochoa Nicholson
I do agree that the temp should be at a molten state to achieve the crackling texture. Hmmmm, my husband is building a small forge so perhaps I can experiment with glass at it's molten state in his forge? Thanks again for the great suggestions and input.
Licha