Shotgun Annealing

Shotgun annealing is a process of annealing glass. Glass than has not been annealed can break any time. It could take a few hours or a few years for this to happen. Your piece could crack or completely break from the stress built up inside.

This procedure does not require you to know the annealing point of the glass. When you don’t know the COE of a glass you will need to do a “Shotgun Anneal”.

This is a process where you take the glass through different annealing temperatures. Stress is relieved over a range of temperatures for different COEs of glass. This process is used when slumping bottles, beads or other pieces of glass where the COE is an unknown factor.

This is a suggested guide that should cover just about any COE through the anneal points and the strain points .

  • Bring temperature down to 1050, soak for an hour
  • Bring temperature down to 950, soak for an hour
  • Bring temperature down to 850, soak for an hour
  • Bring temperature down to 750, soak for an hour
  • By holding the glass at each of the points, you are allowing the glass to reach a uniform temperature and allowing the molecules to move to relieve the stress. You cannot introduce permanent stress into the glass once you are below the strain point .

    Another method of doing this is instead of soaking at a given point, allow the temperature to decline slowly over a range that is large enough to include many different annealing points. The concept is that you can anneal at a number of diverse annealing points as the temperature drops through the range.

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    Fused Glass Instructions

    Glass Slumping Process

    Technical Terms

    Shotgun Annealing to Glass Fusing Made Easy

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