Module 2: Assessment Quiz

Module: U12M2 - Cold Glass Techniques Passing Score: 70%

---

What is the purpose of scoring glass before breaking it?

To create a controlled fracture line along the surface that guides the break

To heat the glass along the cut line through friction

To remove the top layer of glass coating

To measure the glass for accurate dimensions

Submit

Explanation: Scoring creates a shallow surface fracture (not a cut through the glass) that concentrates stress along the intended break line. When pressure is applied, the crack propagates along the score, producing a controlled break.

How many times should you run a glass cutter along the same score line?

Once — a single pass with consistent pressure

Two to three times to deepen the score

As many times as needed until you hear a clean sound

At least four times for thick glass

Submit

Explanation: A score line should be made in a single pass with consistent pressure. Going over the same line multiple times crushes the glass edges, creates chips, and produces an uncontrollable break instead of a clean fracture.

Why must glass grinding always be done with water (wet grinding)?

Water suppresses silica dust, which causes silicosis, and cools the glass to prevent thermal cracking

Water makes the grinding wheel spin faster

Dry grinding produces sparks that are a fire hazard

Water dissolves the glass edge for a smoother finish

Submit

Explanation: Wet grinding serves two critical functions: it suppresses airborne silica dust (which causes the chronic lung disease silicosis) and it cools the glass to prevent localized thermal stress that could cause cracking.

What is the correct grit progression when grinding and polishing a glass edge?

Coarse grit first to shape, then progressively finer grits to smooth and polish

Fine grit first to establish the edge, then coarse grit to remove material

Use only one grit size for the entire process

Alternate between coarse and fine grits for best results

Submit

Explanation: Grinding progresses from coarse to fine. Coarse grit (80-120) removes material quickly and establishes the shape. Medium grit (220-400) smooths scratches left by the coarse wheel. Fine grit (600+) polishes to a finished edge. Skipping grits leaves visible scratches.

What width of copper foil is typically used for standard stained glass work?

7/32 inch (5.6mm) for standard thickness glass

1 inch (25mm) for maximum adhesion

1/16 inch (1.6mm) for delicate work

1/2 inch (12.7mm) for structural strength

Submit

Explanation: Standard copper foil for stained glass is 7/32 inch wide, which provides adequate overlap on both sides of standard thickness (3mm) glass. Wider foil is used for thicker glass or textured edges; narrower foil is insufficient for reliable adhesion.

What must be done to glass edges before applying copper foil?

Edges must be clean, dry, and free of grinding residue or oils

Edges must be heated to 200°C to improve adhesion

Edges must be coated with flux before foiling

Edges must be scored again to create texture for bonding

Submit

Explanation: Copper foil adhesive bonds poorly to dirty, wet, or oily surfaces. Glass edges must be thoroughly cleaned and dried after grinding. Residual grinding slurry, fingerprint oils, or moisture will cause the foil to peel during soldering.

What is the function of flux in soldering copper foil joints?

Flux removes oxidation from the copper surface so solder can bond to the metal

Flux melts the glass edges to create a stronger joint

Flux acts as an adhesive between the glass and the solder

Flux cools the solder faster to prevent thermal damage to the glass

Submit

Explanation: Flux is a chemical cleaning agent (typically oleic acid-based for stained glass) that removes copper oxide from the foil surface. Solder cannot bond to oxidized copper — it beads up and rolls off. Flux ensures a clean metal surface for proper wetting and adhesion.

What is lead came in stained glass work?

H-shaped or U-shaped lead channels that hold glass pieces in place at the edges of a panel

A type of solder made from lead and tin

A coating applied to glass to make it opaque

A lead-based adhesive used instead of copper foil

Submit

Explanation: Lead came is extruded lead strip with an H-shaped cross section (for interior joints) or U-shaped (for panel edges). Glass pieces fit into the channels on either side. Joints where came pieces meet are soldered together to create a rigid panel structure.

What is the primary advantage of copper foil technique over lead came for small, detailed work?

Copper foil allows tighter curves and more intricate detail because it conforms to the glass edge

Copper foil is stronger than lead came

Copper foil is cheaper than lead came

Copper foil does not require soldering

Submit

Explanation: Copper foil wraps directly onto the glass edge and conforms to any shape, including tight curves and small pieces. Lead came is rigid and requires wider channels, making it unsuitable for fine detail work but excellent for larger, simpler geometric designs.

What type of soldering iron tip is recommended for stained glass copper foil work?

A broad, flat chisel tip that distributes heat evenly across the foil joint

A fine pointed tip for precise heat application

A round ball tip for decorative bead work

A hollow tip that feeds solder automatically

Submit

Explanation: A broad chisel tip (typically 3/8 inch) provides even heat distribution across the copper foil seam, creating smooth, consistent solder beads. Fine tips concentrate too much heat in a small area, risking glass cracking and producing uneven joints.

What safety precaution is required when cutting glass that does not apply to most other workshop activities?

Controlling glass shards and fragments, which are razor-sharp and nearly invisible on work surfaces

Wearing a respirator to filter glass vapor

Grounding yourself to prevent static discharge

Working in complete darkness to see score lines

Submit

Explanation: Glass scoring and breaking produces tiny razor-sharp fragments and slivers that are difficult to see on work surfaces. These cause deep cuts easily. A dedicated cutting surface must be kept clean, and fragments must be swept (not wiped by hand) into a glass waste container.

When breaking a scored piece of glass, where should pressure be applied?

On both sides of the score line, with the score facing up, applying even outward pressure

Directly on top of the score line, pressing down firmly

On one end only, snapping the glass like a stick

At the corners of the glass, pulling diagonally

Submit

Explanation: The score line is placed face-up and even pressure is applied on both sides using running pliers or by hand. This opens the score fracture from below, propagating the crack cleanly along the scored line. Pressing on the score or uneven pressure causes the break to deviate.