Slumping Tempered Glass -

Slumping Tempered Glass

This is the main board for discussing general techniques, tools, and processes for fusing, slumping, and related kiln-forming activities.

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Greg Rawls
Posts: 147
Joined: Sun Mar 09, 2003 8:11 pm
Location: Charleston, SC

Slumping Tempered Glass

Postby Greg Rawls » Thu May 17, 2018 4:27 pm

I want to make some round bowls with sandblasted images. I'm too lazy to cut and finish the edges on 1/2" float glass, so I found a distributor for 12" tempered glass table tops that will work. My stupid question (because I think I know the answer): if I slump the glass at 1175 before sandblasting, will it take the tempering out so I can sandblast without the glass shattering?


Tony Smith
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Joined: Sun Mar 09, 2003 5:59 pm
Location: Massachusetts, USA

Re: Slumping Tempered Glass

Postby Tony Smith » Thu May 17, 2018 8:21 pm

1175 with a good anneal on the way down will remove the tempering. That said, you can sandblast tempered glass without it blowing up. A light etch will work just fine.

The tightrope between being strange and being creative is too narrow to walk without occasionally landing on both sides..." Scott Berkun

Posts: 574
Joined: Mon Jan 28, 2008 5:22 pm
Location: S.E. Queensland Australia

Re: Slumping Tempered Glass

Postby Buttercup » Fri May 18, 2018 8:08 pm

If you really want a thrill try carving tempered glass. Once I was supplied with glass that was not supposed to be tempered but was. It didn't have any logos to indicate it had been tempered so I spent hours laying out very intricate artwork then took it into the booth and started carving.
It went off like a blast out of a shotgun! On top of that I had to redo artwork on three new panels.
Last edited by Buttercup on Tue May 29, 2018 7:46 pm, edited 1 time in total.

Posts: 574
Joined: Mon Jan 28, 2008 5:22 pm
Location: S.E. Queensland Australia

Re: Slumping Tempered Glass

Postby Buttercup » Fri May 18, 2018 8:13 pm

Greg, just a thought. Could you not simply order the glass as you want it, without having to reprocess it? I've done that for years. Jen

The Hobbyist
Posts: 304
Joined: Sun Mar 09, 2003 7:09 pm
Location: Sun City West (NW Phoenix), AZ

Re: Slumping Tempered Glass

Postby The Hobbyist » Sat May 19, 2018 11:38 am

Sure, you can order exactly what you want/need but there are so many glass table tops floating around at great prices, new and used. Many of these are tempered and some are not. The savings are worth the effort if you can work with that glass.

I just trashed a 5' = 60" diam x 3/4" glass top that I tried unsuccessfully to give away. I had bought a dining room table and four chairs and only wanted the table base. The chairs were easy to gift but not the top. I got it at an auction for nearly nothing.

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

Ed Cantarella
Posts: 155
Joined: Mon Feb 26, 2018 3:49 pm
Location: Highland, Michigan, USA

Re: Slumping Tempered Glass

Postby Ed Cantarella » Mon May 21, 2018 12:56 pm

Greg - I looked at online prices. . . very good deals for a cut and beveled piece of that thickness. Since you are slumping them the fact that they are tempered means you can get 2-5 times as clumsy without breaking them - until slumped of course. :mrgreen: I really like this idea 8)
HER last words were, "I'm melting, melting . . . " Dissenting opinions generally welcome for comic relief or personal edification. Sometimes both.

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