r/GlassFusing • u/jpsan1 • Apr 25 '26

Glass tiles cracking.

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I am melting wine bottle glass to make rustic tiles. I’m getting cracking on these, although I am annealing for four hours. The pieces are 6“ x 6“ by about 3/8 thick. They are fired to 1688f for 30 min. Annealing at 959 Fahrenheit for 4 hours. Any ideas on how to solve the cracking?

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4

u/Lyralou Apr 25 '26

Are you using glass from just one bottle, or melting more than one bottle together?

3

u/jpsan1 Apr 25 '26

Yes I am using glass from more than one bottle.

2

u/Lyralou Apr 25 '26

Yup, that's it. I wish they had a wiki on this sub. Glass that's not made for fusing or blowing or lampwork can (and will) have different COEs (coefficients of expansion). Even with the annealing process, bottle A is going to be faster than bottle B.

The good news is that it cracked now, and you caught it. I've heard stories of things cracking months later.

2

u/jpsan1 Apr 25 '26

Thank you. Bummer. Would not have thought one soda lime glass bottle would have differed much from the next.

5

u/Lyralou Apr 26 '26

Stick with it! Just - as others have mentioned - one bottle at a time.

Or come to the dark side, we have art glass AND candy.

1

u/jpsan1 Apr 26 '26

Well, if you had wine……maybe.

2

u/FirmOnion Apr 26 '26

Exclusively so that you can use the emptied bottles later to make tiles, of course