Crushed Glass Casting System
Recycled glass set in gypsum — pieces that shift with the light through the day.
Specifications, explained
The numbers that decide how a cast behaves — and what to watch for at each step.
Material & mix
- Base High-strength gypsum
- Harder than pottery plaster, so thin walls survive demoulding without chipping.
- Aggregate Recycled glass — 0.71–1.25 mm
- The same fine, uniform grain is used across coasters and tealight holders.
- Mix ratio Gypsum : water = 100 : 38 by weight
- Too much water costs strength and leaves a chalky surface. Weigh it, do not eyeball it.
- Batch yield 900 g → 4 square coasters
- One batch fills a four-cavity coaster mould with very little waste.
Timing & cure
- Working time 8–10 minutes after mixing
- Past that the mix thickens and stops flowing into fine detail.
- Demould 15 min coasters · 25 min holders
- Too early and the edges slump; too late and the piece fights the mould.
- Full cure 24 h — handling strength in 2–6 h
- Handling strength comes early, but sealing and load-bearing should wait a full day.
- Sealing Once fully dry, dip in the polyurethane sealer for 20–30 s, then air-dry
- The dipped coat cures into a glossy protective layer.
Finished piece
- Edge safety P2500 (2000-grit) sanded rims
- Glass chips sit flush once grouted; sanding the rim removes any proud edges.
- Surface Matte · P2500 (2000-grit) edges · PU sealed
- Sealing locks the aggregate in and stops oil and water marks soaking into the surface.
- Water resistance Water-resistant once the film dries
- Once the sealed surface dries into a cured film, it offers a degree of water resistance.
- Room temperature 18–25 °C ideal
- Below 10 °C curing slows sharply and the surface stays soft for days.
Products in This System
Crushed Glass Coaster Set
Four coasters of recycled crushed glass set in gypsum — they catch the light.
Crushed Glass Tealight Holder Set
Two glass-flecked holders that throw warm light patterns on the wall.
Rose Terrazzo Oval Tray
An oval terrazzo tray in a soft rose finish, cast by hand with dyed crushed glass.
Irregular Metallic Glass Chips
Irregular metallic glass chips for DIY crafts, resin and epoxy fills, and cast décor — 44 colours in 50 g bags. Mix any colours in one order.
Aurora Iridescent Glass Chips
Iridescent aurora crystal glass chips for DIY crafts, resin and epoxy fills, and cast décor — 30 colours in 20 g bags. Mix any colours in one order.
Aurora Glass Pebbles
Transparent iridescent glass pebbles for DIY crafts, resin and epoxy fills, slime and cast décor — 11 colours in 50 g bags. Mix any colours in one order.
More Like This
Other Systems
Water-Based Pigment
Water-based liquid pigment that tints the whole cast — 24 colours, mixed straight into the water.
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Natural Crushed Stone
Gypsum cast with natural crushed stone for warm, tactile pieces with real mineral character.
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Stone Mosaic
Gypsum set with stone mosaic pieces for intricate, one-of-a-kind patterns.
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Mixed Texture
Gypsum cast combining crushed stone, glass and mosaic for one-of-a-kind texture.
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Polyurethane Sealer
Protective polyurethane topcoat that seals, hardens and water-proofs finished plaster surfaces.
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Silicone Moulds
Reusable silicone moulds that flex the cast free — cast the same shape again and again.
Explore System →Start Your Crushed Glass Project
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