Laboratory glassware is made from two things: straight drawn tubing, and a flame that softens it enough to bend, seal, join and blow into bulbs. Test tubes, beakers, flasks, condensers, thermometer bodies, pipettes and burettes can all be made this way. Use borosilicate for anything that will be heated, because a soda-lime beaker heated on a flame will shatter.
Part of Glass Blowing and Forming
Making chemistry glassware from drawn tubing and flame work.
A Chemistry Laboratory Is Mostly Glass That Has Been Bent And Sealed
Laboratory work needs a container that does not react with what is put in it, is transparent so you can see what is happening, and can be heated. Glass is the only common material that does all three, which is why the carrier names laboratory gear first among its uses. The corpus’s Laboratory Ware article covers the same ground at an earlier phase; this carrier adds the three skills below.
| Skill | What it makes | Article |
|---|---|---|
| Drawing tube | Uniform tubing, 1-30 mm diameter | Glass Tube Drawing |
| Lampworking | Bends, bulbs, seals | Lampworking |
| Joining | Condensers, apparatus from several parts | Joining and Sealing |
What You Need
- Glass: borosilicate for heated ware, per Glass Types.
- Tubing, drawn or salvaged.
- A burner with forced air.
- An annealing oven; every flame-worked piece is annealed.
Method: What Each Item Needs
- Test tube: sealed tube, open end fire-polished.
- Beaker: wide tube with a flattened base.
- Condenser: a tube within a tube, with sealed ends.
- Distillation apparatus: flask, condenser and receiver, all connected.
- Thermometer bodies, pipettes and burettes: drawn tubing.
These items are the carrier’s list.
Common Mistakes
- Using soda-lime for heated glassware. It will shatter on a flame.
- Skipping the oven. Flame work adds as much stress as blowing does.
- Mixing glass types in one joint. Different glasses expand differently when heated and cool differently; a joint between them may crack.
Safety
Hot glass does not look hot
Tubing and bulbs that have just left the flame fall below the glow threshold of about 600 °C almost at once, and look like cold glass while still burning. A bench of laboratory glass can contain pieces that were hot a minute ago and that nobody can tell apart from cold ones. Keep a marked tray for work in progress.
Broken glass edges and sealed vessels
A cut tube end is sharp until fire-polished. A sealed vessel that is heated can burst; never heat a sealed piece.
What’s Next
- Learn next: Glass Tube Drawing — the raw material
- Combine with: Lampworking (Flameworking) — forming the items