Tack fused 24x24 not flat

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vrinner
Posts: 1
Joined: Tue May 29, 2018 1:57 pm

Tack fused 24x24 not flat

Post by vrinner »

I tried doing a tack fused chess board. It's all spectrum 96 glass. Squares are 2x2 sitting on top of a 24x24 clear ice.
Kiln is a Scutt GM1414
I used the pre-programmed SLOW Tack

Appears to tack together however it ended up the edges were slightly lifted off the shelf so it's not flat.

I'm thinking compatibility but it's all 96 glass.

I'm thinking about just refiring full fuse to see what happens.

Any thoughts or anyone else done a chess board another way?
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Eric Bloom
Posts: 7
Joined: Fri May 15, 2020 3:39 pm

Re: Tack fused 24x24 not flat

Post by Eric Bloom »

I had a similar problem ... Youghiogheny 96, piece was about 10 x 12 inches. After full fuse it seemed not quite flat. It broke in half during a slump fire - sometime during the anneal or cool down - the shape was correct, just in 2 pieces now.

Maybe incompatible glass - the top layer is Y96-7937M which is 3 different colors. I had some difficulty cutting this glass, maybe the colors had compatibility issues? Or compatibility issues with the clear on the bottom?
Kevin Midgley
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Joined: Mon Mar 10, 2003 11:36 am
Location: Tofino, British Columbia, Canada

Re: Tack fused 24x24 not flat

Post by Kevin Midgley »

vrinner your glass is only tack fused as indicated by the square edges.
Always full fuse glass and anneal slower and longer than all the tables show BECAUSE every kiln has variations.
Brad Walker
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Re: Tack fused 24x24 not flat

Post by Brad Walker »

Large pieces can warp if not annealed properly. in addition, the stress can build up and cause the piece to crack. This can happen with both tack fused and full fused pieces.

With this kind of piece, you can't just go into your anneal hold as you would with a smaller piece. Instead, you need to hold for thirty minutes to an hour about 100 degrees F or so above the annealing temperature, then anneal as normal. This hold relaxes the piece and allows it to anneal properly.

There's more information about this on page 99 of my book Contemporary Fused Glass. https://warmglass.com/contemporary-fused-glass/
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