Resin is a useful, durable material that is poured into a mould to form a variety of shapes. There are many reasons to make an animal from resin. Resin animals are suitable for sculpture or for a craft project. Resin is also good for making customised toys. For instance, a mould for a sheep could make a flock of sheep for a model train setting. With the proper tools, making a custom mould and resin animals is not difficult.
Create a box from the cardboard and tape that has no top or bottom and will fit comfortably around the animal that you are creating a mould for. Some people use Legos to make a box, as they are convenient, sturdy and reusable.
Press non-drying clay into the bottom of your box.
Press your animal piece halfway into the clay. Determine a good location for the resin to pour easily; the back or the head of the animal is likely best, though this will vary depending upon the animal and the shape. Sculpt an opening at this location or place a small object there that leads from the animal to the edge of the box so that the mould will have an opening for the resin. Form some small indentations in the clay as well. These will help ensure that the two halves are put together properly when you cast your piece.
Roll an equally-sized ball of each part of your two-part silicone putty and mix them together for about a minute, rolling them in your hands until thoroughly blended. Press this firmly into your mould, over the animal and clay.
Wait for the putty to set. The timing for this will vary depending upon the brand, but it is typically fast, about five or six minutes.
Turn the mould over. Remove all of the clay from the bottom of the box. Mix a new batch of putty and press it onto the other side. Wait for it to set, then take apart the box, mould halves and animal.
Hold the two mould halves together with a rubber band.
Mix your casting resin in the plastic cup, stirring it thoroughly with the craft stick. Specific instructions vary according to brand, but casting resins always have two parts that must be mixed together. If desired, add a few drops of dye to the resin at this time. This will save time later if you decide to paint the animal.
Pour the resin carefully into the mould. Tap the mould gently to help release trapped air.
Wait for the resin to set completely. This may take 24 to 72 hours, though 24 is more typical. If the air is too cold, the resin will not set properly.
Remove the resin animal from the mould. Trim any resin that may have leaked into the mould with a craft knife, as well as any resin in the opening used for pouring. If desired, paint with model paints to make the animal look more realistic.
If your animal is quite large, you may need to use traditional silicone rubber rather than the putty. Traditional silicone rubber takes longer to cure and is prone to bubbles, but the process of building a mould for silicone rubber is very similar. Protect your work surface with newspaper or a dropcloth. Always work in a well-ventilated area when working with resin.