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The Casting and Construction Interactive Online Workshop shows you how to cast various shapes in fine casting plaster by making clay moulds. The elements you cast are then joined together with more plaster to make sculptures. To visit the interactive workshop click on the link above (requires Flash).

1. Collect your materials*. You will need:

• clay
• clay tools, or objects to press into the clay
• board to work on
• plaster
• water in a bucket

2. First make the mould. Using your hands, make your clay into a slab shape which is at least 10cm thick

3. Experiment with making impressions in your clay. Push in various tools and objects, and then pull them out to leave impressions in the clay. You can use your hands too. Remember:

• Make the impressions as deep as possible
• Make sure the "walls" around your impressions are thick and strong
• Make sure there are no holes in your walls, so that the plaster doesn't leak out
• Make a number of impressions - you can cast them all.

Really experiment - and remember that sometimes the ones you nearly through away are often the most interesting!

Once your mould is finished, you are ready to mix the plaster.

4. Take a bucket or container of clean water. Wear a mask as the plaster is dusty, and if you want to you can wear a latex glove. Then:

• Sprinkle handfuls of plaster into the water - Don't let you hand touch the water though!
• Let each handful of plaster settle
• Keep sprinkling until plaster "islands" appear on the surface - islands are small areas of plaster which don't sink
• As soon as you see islands, and think you have enough plaster to water, mix with your hand. Crush any lumps you feel with your finger tips and make sure the plaster feels smooth
• The plaster should coat your hand like a glove.

5. Pour the plaster into your mould. Have a spare bit of clay ready to plug any leaks!

6. Let the plaster set for at least 25 minutes.

7. Pick the wet clay form around the set plaster to reveal your cast.

8. If you make a number of pieces you can construct with them. To join two or more pieces of plaster:

• Arrange your pieces next to each other.
• You are going to cast a third piece to join the first two pieces together:
• Build clay walls where your two pieces meet. In effect you are building another clay mould, but this time your mould will include two pieces you have already made
• Again, make sure there are no holes where your clay walls meet the made plaster shapes.
• Mix a small amount of plaster.
• Pour the plaster in the gap made by the clay walls. Leave to set before removing the clay walls.

9. Photograph your finished sculpture! - send a jpeg image of your sculpture to info@accessart.org.uk - we might add it to our workshop!

10. Send us your feedback. Tell us what you think about our Casting and Construction - email feedback@accessart.org.uk

Teachers Notes:

* Buy cheapest school clay from schools supplies or art shops, around £3 for a 12.5kg bag. Buy fine casting plaster from a builders yard, around £6 for a sack.