Stage
Work through the stages in order. Blowing before the gather is even gives an uneven bubble.
Controls
Presets
Output
Colour shifts from molten orange toward translucent blue as the gather cools, the way a real gather does.
Important
Simulation results are estimates for learning only. Actual glass behaviour depends on your materials, your equipment and your technique. Follow the manufacturer's instructions and take hands-on instruction before working with hot glass.
How it works
The simulator walks through the three moves that define the opening of every blown piece. First the pipe dips into the furnace and a gather builds on the end, growing as you hold it in the melt. Then the pipe rotates, which keeps the gather spherical against gravity. Then air goes in, and the bubble inflates at a rate set by your blow pressure.
The interesting part is what happens to the numbers. Volume grows with the cube of diameter, so a bubble that looks only slightly larger may hold twice as much glass. Wall thickness moves the other way: inflate the same gather to twice the diameter and the wall becomes roughly a quarter as thick at the equator. The annealing estimate at the bottom of the panel follows the wall thickness, because thick glass has to cool more slowly.
Controls
- Gather size
- How much glass is on the pipe, in millimetres of gather diameter
- Blow pressure
- How fast the bubble inflates while the blow button is held
- Rotation speed
- Pipe rotation, which keeps the gather round and even
- Temperature
- Gather temperature, which changes colour and stiffness
What you get out
- Volume estimate (ml)
- Outside diameter (mm)
- Wall thickness estimate (mm)
- Suggested anneal time
These simulations are a teaching aid. They do not make anyone competent to operate a furnace, glory hole or kiln. Real work requires eye protection, heat-resistant gloves, working extraction, a carbon monoxide alarm and hands-on instruction.