slumped glass, done in pieces in a big kiln.

Most likely made with tempered glass or similar.

Although there may be a mass produced version i have only seen it hand made; where formwork is placed inside a kiln and a sheet of glass laid down upon it and allowed to slump (basically allowed to fit the formwork/shape as it melts and deforms under heat and gravity). The process is fairly expensive and tends to result in a few bad pieces that break. Installation is otherwise easy enough but a delicate job and frustrating for the contractor if the glass breaks on site. I expect it is also possible to make the formwork with CAD data and a milling system, so you can get a great deal of accuracy, though I have not tried this (yet).

hi jump, thanks

what kind of formwork? is this made by hand trying to follow a model (by eye)? how do they get the measurements just right so the glass fits together perfectly?

how do you mill glass? what kind of shape of glass do you start with and what kind of milling device/cutter is used?

I read that gehry uses corning glass.

if its tempered, would it be possible to use this kind of glass and mullion-less design in hurricane-prone areas?

anything's possible with an unlimited budget....

Check out CTEK, they make most of the slumped glass you'll see in the Archi mags. I know that Michele used them to make his instalation at SCI-Arc. I'm not sure if they also did his stuff in France.

The formwork is milled, not the glass, by a CNC router.

very hard to install w/o breaking

And a goddamned s.o.b. to replace...

try the program CATIA. A.Zahner Co. out of KC uses it to develop assemblies for some projects that have that fluid facit thing going on.

what would the formwork be made out of? presumably some type of heat-resistant polymer?

i used clay. with a release powder. (don't recall the substance's name)

i wonder how auto glass suppliers mass-produce compound curved pieces?

http://www.moparstyle.net/history/chrysler.htm

"1934 saw the introduction of the Chrysler Airflow and Desoto Airflow vehicles. These were seen as an “engineer’s car” and incorporated many engineering advances. The top of the line Chrysler Custom Imperial Eight saw the first use of a one-piece curved windshield. Many of the Airflows features would go on to be standard design features by the auto industry worldwide. "

"The Imperial introduced curved side glass, as well as compound curved windshields, further expanding design possibilities. Another first is introduced in 1958. "

I have used or seen an enormous variety of materials depending on the application. For casting you can use metal,clay, and surprisingly cork gives a clean effect. But for this kind of application I believe ceramic is the typical choice. the form can be made pecisely with cad-cam for the slump, and if the fabricator is good then you are ready to rock.

As m. Fog mentioned above, you might want to contact CTEK; their website is here:

http://www.ctek.us/

looks good to me (check out the architectural glassmaking bit). If you have a google about you should be able to find similar firms nearby. Or just call up a glass artist and ask for their advice. They'll likely know better than anyone.

thanks to all for the great info.

Not sure what the origional project is but the the one Javier posted os the green umbrella by Moss. I know that was designed in 3dmax/vis and acad. They would test drainage by moving a plane or solid down through the model to see if any parts would pool. They also did the steel shop drawings in house. Dont remember how they fabricated the glass on it.

Jrocc, IIRC they heated the glass somehow and bent it with sandbags and sand forms... it was a long time ago that i read about the fabrication of the glass so i could be mistaken.

they slumped the glass over an egg-crate-like topography in huge kilns, if i recall correctly.

and i think you're right, 3ifs...they weighed it down with sand...? i think. part of the difficulty was the steel work and the clamps... those conform very precisely to the computer model, but the glass that comes out of the kiln is not exactly like the modelled version, so it the disparity between the clamp positions and the glass outcome creates points of stress where the glass would begin to crack. i think they might have started to remodel the steel pieces after the glass came out to correct the mismatches. i think i saw someone's presentation on this once at sciarc. it was several years ago so i don't remember all the messy details.

it would have made more sense to design the steel armature with movable mounting points for the glass.

ctek