This week we will continue to make the multi cavity mould out of silicone.
You will need:
- Silicone part A and B from AMT. All you need to know about Silicone.
- A silicone release agent from AMT
- A stirring stick
- A disposable container to mix in big enough to hold part A and B
- The individual resin pieces we made in part 2
- A wooden/plastic "box/frame/container" large enough to incorporate all the resin pieces
- Plastic/ Cortex board to line the mould if you use a wooden box
- Glue gun
- Scale – a good digital one
- Prepare your mould/container, making sure it is on a flat surface and within easy reach to pour the silicone into it.
- Weigh your all resin pieces together and write the figure down somewhere
- Measure the size of your box: Length, breadth and height and work out the volume by multiplying the 3 numbers together. i.e. LxBxH. Write this figure down as well
- Take the figure of your resin pieces and subtract it from the volume worked out above. Write this number down. This is hoe much silicone you will need to mix up. Technically this is not totally correct as you need to take the specific gravity of the silicone into account. I have just cut a few corners
- Have another container ready with something else you may want to mould as a back up in case you have mixed too much silicone
- Take your box and line it with the Correx making sure there are no gaps where the silicone can escape
- Place all the resin pieces into the box to test how they will fit best leaving about 3/4 to 1 cm gap between each piece so the walls will be stable. You will need to place them TOP side facing up
- Remember how you laid the pieces and remove them all
- Take the glue gun and place a small amount of hot glue all around the base of the resin piece and glue it onto the base of the box lined with Correx. if you put too much glue it will “squish” out the sides and you don’t want this. Continue to glue all the pieces onto the base
- Once they are all glued mark a line 1cm above the highest point of the resin pieces
- Spray the Correx and all resin pieces liberally with the release agent – as per manufacturers instructions. You should also have your other mould ready and sprayed in case you need it
Mixing and pouring the silicone:
- Mix up the silicone as per manufacturers instructions using the amount we worked out earlier
- Pour the silicone over the resin pieces from a high spot so it comes out in a long, thin stream. This is to stretch the silicone and remove all the bubbles
- Try to pour in one spot over a resin piece and allow the silicone to fill up the gaps and the mould
- Fill the mould to the line you marked
- Leave for 24hours to set or as per manufacturers instructions.
- Once set you can remove the mould from the box and peel off the Correx. remove all the resin pieces and there you have it – a multi cavity mould
Please be adventurous try this. It really is fun