Tempering Glass

[Ralph Laborde]

Does anyone have any experience tempering COE96 glass rondels for an outdoor art installation?

Break out the Salt Peter

https://en.m.wikipedia.org/wiki/Chem...ngthened_glass

[Pete VanderLaan]

and then try to avoid getting on a DHS watch list for buying it.

[Tom Fuhrman]

check with John Lewis, he's done lots of outdoor installations. I suspect that may have been a spec for some installation written by an architect that has no idea what the nature of handblown glass is really all about. The outdoor installations I've done were never tempered and have been outside for going on 20 years. If safety is an issue then you may have them coated with some of the clear silicone material that keeps them from breaking into slivers but usually makes the glass look terrible with no luster to it.

[Rick Wilton]

Good luck, I worked at a glass plant for a while and we tried tempering spectrum sheet glass, bullseye and even float glass that had been fused together. The results were always the same they'd explode into millions of pieces, some would die immediately during the quench others would tease you and survive to at least get out of the tempering furnace. All it takes is an airbubble, a seed, a speck of refractory etc for it to explode. Even perfectly clear float glass has a failure rate for the same reasons. When I worked there we made a few outdoor installations using sheets of spectrum for a huge outdoor monument. These sheets were laminated to tempered glass to make them meet code.

Chemical tempering does make the glass stronger but it does NOT meet the same code guidelines as heat tempering. Chemical tempered glass still breaks like regular glass.... ie sharp

[Pete VanderLaan]

I think one of the real troubles with installation type jobs is the place that wants it gets lawyers and bureaucrats too close to the process. They all live to indemnify themselves. In Public Installations, you wind up filling out tons of forms on your hiring practices, compliance with codes, on and on. In bathrooms, it's a total nightmare. I can't really get excited about having to jump through someone's hoops over trying to get that work and this sounds a lot like those hoops.

As Edward Abbey once said "I smell Lawyers here..."

[Tony Serviente]

Bob at His Glassworks used to sell something called FlexTec. It is a thick 2 part epoxy that you brush onto the glass. In case of glass failure it holds the pieces together quite well. I tested it and it was very good. It is the same concept as laminated, but a surface application. It does not leave a clear surface, and its working time is very limited, but it was just what we needed for a lamp job.