Glass Furnace
The melting tank that holds glass at working temperature, day and night, for the whole life of the studio.
Gathering
| Opening diameter | 150 - 300 mm |
|---|---|
| Operating temperature | 1000 - 1250 °C |
| Heat source | Natural gas and air, or electric elements |
| Typical reheat time | 5 - 20 seconds per pass |
| Body | Refractory lined steel shell |
Compatible glass types
Soda-lime
Borosilicate
Lead crystal
Compatibility assumes the tool is rated for the working temperature of that glass family. Check the maker's documentation before use.
Overview
Between shaping steps a piece cools fast, and cold glass will crack the moment a tool touches it. The glory hole is a small, intensely hot chamber with a wide opening that lets you reheat just the part you are working on. It sits at a slightly higher temperature than the furnace, around 1150-1250 °C, so a few seconds inside brings the surface back to working temperature.
Safety notes
- The opening is the hottest surface in the studio. Use a heat shield on the pipe and never reach past the mouth.
- Gas-fired glory holes need working extraction and a carbon monoxide alarm in the room.
- Long objects inserted too far will ignite. Keep a fire blanket within arm reach.
Using it well
Practical guidance
- Rotate the pipe continuously while reheating so the piece heats evenly and does not sag on one side.
- Short, frequent passes beat one long soak. Long soaks soften the whole piece and let it slump.
- If the surface sparks, the glass is too close to the burner ports.
What to look for
- Wide mouth for angled access to one area of a piece
- Adjustable burner ring for even radiant heat
- Refractory sill that supports a resting pipe
High temperature tool
This tool operates in or near the working range of molten glass. Read the safety notes above before first use, and never work with it without eye protection, heat-resistant gloves and working extraction.
Reference information only. Specifications are published ranges drawn from manufacturer documentation and normalised for comparison. They vary between makers and between individual units. This page does not sell or endorse any product, and does not guarantee any result. Follow the equipment manufacturer's instructions and take hands-on instruction before operating hot glass equipment.
Related
Tools used alongside the glory hole
Annealing Oven
A front-loading chamber for bringing finished pieces down through the annealing range under control.
Annealing
Kiln Controller
The programmer that executes a ramp-and-hold schedule and holds the furnace to it.
Annealing
See the furnace & heating workflow
Read the category overview, or jump into the 3D Studio to see these tools applied to a live piece.