Glassblowers shape hot glass with jacks (flat-bladed tweezers that constrict and open), paddles (flat wooden or graphite blocks that flatten), tweezers (which pull and pinch detail), diamond shears (which cut hot glass) and a marver slab. Any surface that touches the glass must be smooth and either wet wood or a material that does not stick, such as graphite or polished steel, because a sharp edge cracks the piece and a dry tool sticks to it.
Part of Glass Blowing and Forming
The hand tools used to form, open, flatten and cut glass while it is hot.
Each Tool Changes One Feature Of The Piece
The carrier article and the corpus’s Glassblowing article together describe the set.
| Tool | Form | Job |
|---|---|---|
| Jacks | Large tweezers with flat blades | Constrict a neck, open a rim, shape form |
| Paddle | Flat wooden or graphite block | Flatten a surface |
| Tweezers | Long iron pincers | Pull and pinch decorative details |
| Diamond shears | Large scissors with flat blades | Cut hot glass |
| Wet wood block | Hollowed fruitwood cup on a handle | Round the first shape |
| Marver | Flat steel or marble slab | Roll and centre the gather |
Wood stays wet because the steam it makes forms a cushion between wood and glass, per the glassblowing article.
What You Need
- Steel for jacks, shears and tweezers; forged and then filed smooth.
- Fruitwood (cherry, apple) for blocks and paddles; kept in a bucket of water within reach.
- Graphite or polished steel for paddle faces where wood would char.
- Cooling water, in small quantities, for the thermal-shock separations.
Method: Using Each Tool
Step 1: Block the first shape. Roll the gather in a wet block while the pipe turns. The surface steams and the piece rounds.
Step 2: Jack the neck. Place the jack blades around the glass and squeeze gently while rotating. The constriction marks the break point where the piece will be cracked off.
Step 3: Open and flare. After the transfer to the pontil, widen the opening with the jacks in the reheated end.
Step 4: Flatten with a paddle. Press the flat face against the surface of the turning piece.
Step 5: Trim with shears. Cut uneven edges while the glass is still hot; the glassblowing article uses this step for the lip.
Step 6: Pull detail with tweezers only after the piece is reheated, because cold glass tears.
Common Mistakes
- Dry wooden tools. They char and stick instead of steaming.
- Burrs on steel jaws. The carrier states that every sharp edge can crack the glass.
- Tools left in the glory hole. They overheat and their faces pick up glass.
Safety
Hot glass does not look hot
A jack or paddle that has touched hot glass can stay hot long after it has stopped glowing, and glass below about 600 °C shows no colour at all. Rest tools in a marked rack, never on the bench among cold tools.
Flying shards
Shears and thermal-shock separations throw hot glass fragments. Wear eye protection and keep bare skin covered below the face.
What’s Next
- Learn next: Glory Hole (Reheating Furnace) — keeping the work soft enough to shape
- Combine with: Shaping and Finishing — the sequence of operations