Used for mould making and casting.

Instructions

To find the amount of plaster/water mixture needed for your cast, firstly fill the mould with clean water and pour it into a mixing bowl. Dry the mould prior to casting. On average ratios are 850g of plaster to 1 pint of water. Slowly pour plaster into the water and stop when the mound of plaster powder starts to show above the water. Mix gently, but quickly, until you have a smooth creamy consistency. Try not to whip/beat the mixture, as this will create air bubbles.

Whatever type of mould you are using, firstly pour in a small amount of plaster mixture and encourage it to go into any fine details, then continue to fill the mould. Tap the sides/base of the mould to dislodge any air bubbles and help them float to the top.

Leave the plaster to dry at room temperature for approximately 30 minutes then carefully remove it from the mould. To dry out completely the cast must be left to stand in a warm place for at least 24 hours.

Information taken from the Specialist Crafts website.