Materials and equipment:- model
- mould release (I use soft soap or watered down clay slip)
- containers for mixing and measuring
- plaster (I use Gyprock Superfine Plaster)
- paper pulp ( available in bulk from roof insulation places)
optional: kitchen timer
A word about undercuts:
1) Preparing the model
2) Mixing the plaster
4)Mixing the paper plaster
Usually you will need more volume of plaster for the second layer, as it is larger.
Start the same way as for the first layer:
5) Preparing the second half
I usually apply it to the sides of the mould as well as the top edge, as some plaster is likely to spill over the side. This will make it easier to clean
6) Repeat steps 2, 3 & 4
And here it is, finished mould. You don't even have to wait fort he plaster to cool down. Gently tap it onto the ground on the seam and it should crack open like an egg. I love this moment.
I tend to let the mould dry for a few days before using it. If you are going to use it for slip casting, you will need to wait for a week or more as the mould needs to thoroughly dry out in order to absorb the water from the casting slip.
If it will be used for a press moulding, it can be used almost immediately.
Did you find this tutorial useful?
Is it similar or different to the way you make moulds?
Do you have suggestions or tips to share?
I would love to hear your comments.