Tempered Glass Shards - WarmGlass.com

Tempered Glass Shards

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smallbitz
Posts: 154
Joined: Sat Jun 27, 2009 8:44 am
Location: Florida

Tempered Glass Shards

Postby smallbitz » Tue Dec 10, 2013 12:41 pm

I've been fusing tempered glass shards and just can't seem to get around the needles on the edges. Fusing into slightly rounded bowl. Any suggestions? Here's my schedule

500/1000/10'
400/1350/17'
full/1015/1.30
250/700
500/300

also tried

500/1000/10'
200/1400/10'
full/1015/1.30
250/700
500/300

both produce very 'needley' edges.

lorimendenhall
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Re: Tempered Glass Shards

Postby lorimendenhall » Tue Dec 10, 2013 2:25 pm

I was told you are not supposed to fuse tempered glass.

Alexis Dinno
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Re: Tempered Glass Shards

Postby Alexis Dinno » Tue Dec 10, 2013 2:57 pm

lorimendenhall wrote:I was told you are not supposed to fuse tempered glass.


Huh . . . wonder if I need to throw out my castings and jewelry then. Or wait: was that a moral "not supposed" or a technical "not supposed?" ;)

One of the most beautiful glass objects I own (or have even seen) is a casting from tempered float.

jim burchett
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Location: Lenoir, NC

Re: Tempered Glass Shards

Postby jim burchett » Tue Dec 10, 2013 5:39 pm

Broken tempered glass makes beautiful objects,try going a bit hotter...1450 and see how it goes...float generally fires hotter than art glass.
"No, you cant scare Me, I'm sticking to the UNION. I'm stickin to the UNION till the day I die" Woody Guthrie

Morganica
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Re: Tempered Glass Shards

Postby Morganica » Tue Dec 10, 2013 7:13 pm

Needles on the edges? Wow--I wouldn't think it would do that with your schedule. The edges can remain sharp, however. I typically tack-fuse these at 1380-1450F for no more than 30 minutes with slow ramp up, and at the 1450 mark the edges are pretty rounded. I suppose if you were letting the shards slide down a mold you might get needlepointing at that level. Depends on what you're looking for. Both of these pieces are tempered glass, with radically different schedules. The bowl was a simple tack-fuse which didn't needlepoint, but left some of the sharp edges intact; I simply hit them lightly with a piece of wet-dry to prevent someone from cutting themselves on those points.
Image
Image
Image

Tempered glass is VERY fusible...as long as you accept that it's not going to behave like fusing glass (and obviously never try to fuse it with fusible glass). Processes for the bowl here:
http://www.morganica.com/bloggery/2007/ ... ds-series/
Cynthia Morgan
Marketeer, Webbist, Glassist
http://www.morganica.com/bloggery
http://www.cynthiamorgan.com

"I wrote, therefore I was." (me)

smallbitz
Posts: 154
Joined: Sat Jun 27, 2009 8:44 am
Location: Florida

Re: Tempered Glass Shards

Postby smallbitz » Tue Dec 10, 2013 7:31 pm

Yes, perhaps I'm just not going hot enough. It's not just sharp edges, it's definately needles. I do have them piled up in the mold so it may be from sliding down. I'll try it a little hotter - 1450 sounds good. I've been fusing tempered glass for years, and never had any problems. Thanks for the advice, I'll let you know what happens. Beautiful pieces

lorimendenhall
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Location: Orange County, CA
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Re: Tempered Glass Shards

Postby lorimendenhall » Tue Dec 10, 2013 10:48 pm

good to know and what gorgeous pieces you made!!!!!

Bert Weiss
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Re: Tempered Glass Shards

Postby Bert Weiss » Wed Dec 11, 2013 1:05 pm

In general I try and keep my top temperatures as low as possible. When I started out working fusing broken tempered, my pieces tended to break easily. Eventually I got hotter and hotter until they maintained better integrity. This is a matter of heatwork which is different from kiln to kiln. If you make a piece and it breaks easily, go hotter, and or soak longer, next time. Once you get hot enough, there will be devitrification. The trick is to find the sweet spot.

The needling thing is caused when your dam is higher than the pile of glass. You can either use fiber paper cut narrowly or fiber rope to line the dam. The glass does not have a tendency to flow over it. It doesn't matter what is behind the front layer, except I would make sure there is kilnwash or paper there too, just in case.
Bert

Bert Weiss Art Glass*
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Peter McCarthy
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Location: Cambridge, MA

Re: Tempered Glass Shards

Postby Peter McCarthy » Wed Dec 11, 2013 4:28 pm

I fuse/slump tempered shards directly in a mold at 1450. I always get a few needles, and I just knock them off with a file. A small jeweler's file can get in between the shards .

smallbitz
Posts: 154
Joined: Sat Jun 27, 2009 8:44 am
Location: Florida

Re: Tempered Glass Shards

Postby smallbitz » Wed Dec 11, 2013 5:25 pm

I think that I may not be firing quite high enough. I'm trying a little hotter. I'll also give the little files a shot. Great idea. I have some small jewelers files that will work great!


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