Here's a simple way to make DIY durable molds using inexpensive ingredients. In this instructable i used my adjusted sticky playdough recipe.
I am making a large boquet of cold porcelain roses and was thinking of ways to make them faster.
There was the option of using silicone molds or plaster paris. However, I was a bit unsure how safe silicone was to handle and plaster paris usually ends up pretty messy.
So I settled on sticky playdough. This sticky recipe picked up all the finer details from the leaves I was casting. And the resulting leaf impressions were surprisingly clear.
Step 1: Sticky Playdough Recipe
Normal playdough recipe is quite smooth and malleable.
However with this sticky playdough recipe, what makes it great for casting is that it is so soft and will enventually dry rock hard.
Instead of a ratio of 1:1 flour and water mix, I add half a cup of extra water.
2 cups plain flour
2.5 cups water
1 tbl tartaric acid / bicarbonate soda (adds bounce)
2 tsp teatree oil / orange oil / nutmeg oil (kills bacteria and prevents mould)
1 tbl salt
1/2 cup lime (calcium carbonate hydrated)
I lowered the amount of salt in the recipe as it has a tendency to create holes when drying, but there is a smooth finish when I added lime powder for some reason. You could chuck in some crushed Calcium tablets if you don't have any lime powder at hand.
Step 2: How to Make an Impression
I covered the back of several leaves I collected with a generous coating of mineral oil.
The back veins are deeper on the leaves than the front and are perfect for casting.
Roll out a piece of clay that is larger than your object for casting. Here I rolled the playdough onto baking paper and pressed it flat with a piece of plastic wrap.
I then pressed the leaves into the sticky playdough.
Step 3: Check the Cast
Air dry in sun for a week. Once hard, I'll impress another set of sticky playdough for a reverse impression.
Watch the live clip for more details.