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Activity 002: Flameworking — Making a Glass Bead

Activity ID: U12M3-ACT-002 Duration: 45 minutes

Overview

Students create a simple glass bead using flameworking techniques. Working with borosilicate glass rods and a bench-mounted torch, students practice flame adjustment, glass introduction, continuous rotation, and mandrel winding. The activity builds fundamental torch skills and reinforces the importance of proper annealing for all hot glass work.

Materials & Equipment Needed

  • Bench-mounted torch (propane/oxygen or natural gas/oxygen)
  • Fuel gas supply (propane tank or natural gas line) with regulator
  • Oxygen supply (concentrator or tank) with regulator
  • Borosilicate glass rods (assorted colors, 5-8mm diameter)
  • Mandrels (1/16 inch stainless steel rods, 12 inches long)
  • Bead release (alumina-based, pre-mixed)
  • Small cup for mandrel dipping
  • Graphite paddle (for shaping)
  • Graphite reamer (for hole cleanup)
  • Annealing kiln (small bead kiln, pre-heated to 1050°F)
  • OR fiber blanket (vermiculite-filled) if kiln not available
  • Fireproof work surface (ceramic tile or kiln shelf)
  • Didymium or IR-rated safety glasses (mandatory)
  • Heat-resistant work gloves (thin, dexterous)
  • Leather apron
  • Hair ties
  • Fire extinguisher (Class B, within 10 feet)
  • Ventilation/fume extraction system
  • Timer

Instructions & Procedure

Part 1: Setup and Flame Adjustment (10 minutes)

  1. Instructor reviews torch safety:
  2. Check fuel connections for leaks (soapy water test)
  3. Confirm ventilation is operational
  4. Verify fire extinguisher is accessible and charged
  5. Confirm all students are wearing IR-rated glasses, aprons, and have hair secured
  6. Instructor demonstrates torch lighting sequence:
  7. Open fuel valve slightly
  8. Ignite with striker (never a lighter)
  9. Adjust fuel to a small, stable flame
  10. Gradually add oxygen to achieve a neutral flame
  11. Instructor demonstrates flame types:
  12. Reduce oxygen: observe reducing flame (bushy, yellow tips)
  13. Increase oxygen: observe oxidizing flame (sharp, hissing)
  14. Balance to neutral: even cone, moderate sound
  15. Students light their torches and practice flame adjustment under supervision

Part 2: Mandrel Preparation and Glass Introduction (10 minutes)

  1. Students dip mandrels in bead release, coating 1 inch of the tip evenly
  2. Allow bead release to dry (hold in flame briefly to cure — do NOT overheat)
  3. Instructor demonstrates glass introduction technique:
  4. Hold glass rod at a comfortable angle (approximately 45 degrees)
  5. Introduce the tip to the outer edge of the flame (cooler zone)
  6. Slowly move into the hotter zone over 15-20 seconds
  7. Begin rotating the rod to heat evenly
  8. Glass tip will begin to glow and soften — this is the working state
  9. Students practice introducing and heating glass rods
  10. Key error to watch: pushing cold glass directly into the hot zone (thermal shock — the tip pops off)

Part 3: Bead Making (20 minutes)

  1. Instructor demonstrates the complete bead-making sequence:
  2. Heat mandrel tip in flame until glowing
  3. Heat glass rod tip until a gather forms (molten ball at the end)
  4. Touch the gather to the hot mandrel and begin winding
  5. Rotate mandrel continuously while feeding glass from the rod
  6. Build up the bead by adding 3-5 wraps
  7. Shape in the flame — gravity and rotation create a round form
  8. Use graphite paddle to flatten or shape if desired
  9. When satisfied with shape, remove from flame gradually
  10. Place immediately into annealing kiln (1050°F) or fiber blanket
  11. Students create their first bead:
  12. Focus on continuous rotation (most critical skill)
  13. Accept imperfect shape — the goal is process, not product
  14. If the glass drips: the mandrel rotation stopped — restart and try again
  15. Students who complete their first bead successfully can attempt a second with color variation or shaping
  16. After annealing (minimum 30 minutes in kiln, or 1 hour in fiber blanket), beads are removed from mandrels

Part 4: Cleanup (5 minutes)

  1. Shut off torch: close oxygen first, then fuel
  2. Allow all tools to cool on fireproof surface
  3. Place all glass scraps in designated container
  4. Wipe down work surface
  5. Remove PPE in reverse donning order

Discussion Points

  • What happened when you stopped rotating the mandrel? Why does gravity have such a strong effect at these temperatures?
  • How did the glass behave differently at the outer edge of the flame vs. the hot zone?
  • Why must the mandrel be hot before applying glass? What happens if it is cold?
  • What would happen if you skipped annealing and let the bead cool in open air?
  • How does borosilicate's low CTE help during flameworking compared to how soda-lime would behave?

Expected Outcomes

  • Students produce at least one complete glass bead on a mandrel
  • Students demonstrate continuous rotation technique during bead building
  • Students can adjust flame type (oxidizing, reducing, neutral) on demand
  • Students properly introduce glass to the flame without thermal shock
  • All beads are placed in the annealing kiln or fiber blanket — no air-cooled pieces

Assessment Rubric

Criteria Excellent (4) Proficient (3) Developing (2) Beginning (1)
Flame control Adjusts flame type on demand, maintains stable neutral flame Achieves neutral flame with minor adjustments needed Struggles with flame adjustment, achieves working flame with help Unable to achieve stable working flame
Rotation technique Smooth, continuous rotation throughout bead building Mostly continuous, occasional hesitation Frequent stops in rotation, gravity drips Unable to maintain rotation
Bead quality Symmetrical, even bead with smooth surface Slightly asymmetric but complete bead Irregular shape, some surface defects Incomplete bead or glass fell off mandrel
Safety compliance All protocols followed without prompting Minor lapses, self-corrects immediately Needs reminders about PPE or flame procedures Multiple safety violations

Safety Considerations

  • IR-rated safety glasses are MANDATORY — torch flame and hot glass emit intense infrared radiation
  • Leather apron protects torso from radiant heat and any glass that falls
  • Hair must be tied back — hair ignites instantly near a torch flame
  • No synthetic clothing — cotton or wool only (synthetics melt and adhere to skin)
  • Hot glass and mandrels look identical to cold ones — assume everything on the work surface is hot
  • Never reach across the flame to adjust gas valves — reach around
  • If glass drops to the work surface, do NOT pick it up — let it cool completely
  • Keep at least 6 feet between workstations
  • If fuel smells unusual or a leak is suspected: shut off gas at source, evacuate, ventilate
  • Annealing is non-negotiable — unannealed beads are ticking time bombs for delayed cracking

Last Updated: 2026-03-19