We get asked all of the time about how to make molds of things that you create. So we are teaming up with our friend Matt Jones of the Plastik Surgery Workshop to give a little advice on the best ways to do this.
Tip 1 - One Piece Tool - Mold Making:
- We call the 3D design you are casting off the Master Model, it can be made from sculpey clay.
- The best way to start is by using a simple 3D designed Master Model like a coin, or a bunny like my example.
- Very mould friendly 3D shapes are mostly conical designs with no drastic undercuts in the design.
- An undercut is happening when you have arms and legs or limbs protruding from the design over 10mm.
- Keep these to a minimum with your first design and when you cast in resin, the figures will pop out easily when casting off in resin.
Tip 2 - Clear plastic cup mold works best for beginners:
1. They are easy to use.
2. Waste less silicone material than square containers.
3. They are easy to get hold of from shop suppliers like supermarkets and you need cups for the casting process and for parties when you release the figures.
You can put your Master Model inside the cup in the center, with a small dab of super glue on its base. The base is where you will pour resin in later, so a larger base ( footprint ) the better. Once you have your Master model in the cup, you can begin to pour mixed silicone into the cup which makes the silicone tool.
Make sure you put at least 10 mm of material over the entire design. Its good to have 10 mm of material all the way around your design to give the silicone rubber tool some strength so it keeps it shape well when casting. Bare this in mind when choosing a cup size, also check the bottom of the cup, to make sure you have a good flat surface, some cups are convex at the bottoms.
Tip 3 - A self built plastic mold case using plastic or card:
This is also a good way to start molding larger shapes and you can make the mold as big or as small as you like, or even a custom shape. I suggest you make silicone tool cases that leave around 10 mm all the way around the edge of your Master Model. Both methods are good places to start and have the same effects.
Tip 4 - Going into 2 Part Silicone tools:
These are 2 pieces of silicone that create one silicone tool ready for casting. I am just about to write the 2nd book on this method- I will have it ready in about 3 months time.
Smooth-on products are my favourite to use. I use Smooth-Cast 300 Resin and Mold Star 30 Silicone.