This site is brought to you by Helios Kiln Glass Studio in Austin, TX.
What it does:
Cools your glass to room temperature.
Things to consider:
As with our initial heating, thermal shock is the number one concern during the final cooling. Not all breaks during final cooling, though, are the result of thermal shock.
Stress in glass has a cumulative effect. A slightly aggressive annealing may not cause the glass to break. Ramping the temperature down a little too quickly during final cooling may not, by itself, result in a broken piece. The stress that results from doing both of these things on the same piece may collaborate to create a broken masterpiece.
If the glass is properly annealed, any break during final cooling is almost always either the result of thermal shock, incompatible glass, or glass sticking to the shelf.