Plaster Casting and Mould Making — A Beginner's Guide

Plaster casting is affordable, beginner-friendly, and incredibly creative — and one of our most popular products, our casting powder, is quite literally flying off the shelves. With plaster and silicone moulds you can create trays, decorations, candle holders, wall sculptures, and so much more. Here's your beginner's guide.

What do you need to get started?

• Casting powder — a strong plaster that sets quickly and gives a smooth, white finish. See Gifsteypuduft (1 kg) or classic Plaster of Paris (1 kg).
• Silicone moulds — trays, jewellery, decorations, and shaped moulds. Browse all moulds and mould-making supplies.
• Want to make your own moulds? Use Silicone Liquid (Shore 15) to cast moulds from existing objects.
• Tools — a mixing bowl, a spoon or spatula, and a measuring jug for water.
• Colour — acrylic paint applied afterwards, or pigment mixed directly into the plaster for solid colour throughout.

Step by step: Your first plaster cast

1. Measure your water and plaster. A general ratio is roughly 2 parts plaster to 1 part water (follow the instructions on the packaging).
2. Sprinkle the plaster into the water — not the other way around. Let it sink and wait about 1 minute.
3. Stir until smooth — the mixture should be lump-free and resemble a thin pancake batter.
4. Pour into the mould and tap it gently on the table to release any air bubbles.
5. Leave to set for 30–60 minutes until the mould feels cool to the touch (plaster heats up as it sets).
6. Carefully demould and leave to dry fully for 24 hours before painting.

Good to know

• Work quickly — plaster starts to set within 5–10 minutes.
• Never pour plaster down the sink — it will harden in the pipes. Let any leftover plaster set and dispose of it in the bin.
• A smooth surface is achieved by tapping out air bubbles and using clean, new moulds.
• Painting: acrylic paint adheres well to fully dried plaster.

Ready to get started?

Browse everything for casting and mould making at Föndurlist. Our casting powder is in stock and ready to ship anywhere in Iceland.