Annealing and Tension in Glass

Hot-working processes used to form a glass object—glassblowing for example—must be followed by a very gradual cooling period called annealing. See what happens when an object is not properly annealed and learn why it breaks.

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[mauiglassblowing]

Wow - what an eye opening video - I appreciate that you are making all of this knowledge public - the glass artists are benefiting greatly !

[hseaman275]

The blocks should be annealed, although it won't take much time. Anneal them by cooling them slowly though the rnage of temperature from annealing to strain point. Since you don't know these temperatures, cool slowly from 950 F to 700 F to be safe, and by slowly I mean about 3 hours for something that size. After that, cool faster from 700 to room temperature, maybe around 6 hours minimum.

[phantommoth]

Hi there, I'm new to glass works and just wondering I've just casted a small block of glass,(about 3 x 4 cm) and I don't know exactly what type of glass it is (but its melting point was low, definetly below 1000 deg c, it was the kind of glass balls which you can buy in the dollar store for bedding your aquarium), how do I anneal it? or does annealing required for such a small block of glass? Thanks very much.

[OhsoScary]

But really thanks to all the Corning videos. Much appreciated!

[OhsoScary]

hot glass pockets