This Halloween I wanted to show how to make something that can be used each year. I first thought about making a mold of a real pumpkin, but I realized I can skip a step and use the pumpkin, as is, on the vac former.
Vac forming styrene plastic over a form often gives you a flange that is inconsistent, so I use 1/4″ MDF to raise up my two halves. After cutting off the flange, the formed styrene has a matching parting line that is easier to adhere together. To glue the halves I use methylene chloride glue for plastic. To fill the gaps I use PlasticWood — it has acetone in it to etch into the surface. I add more acetone to make it thinner, to use for the plastic.
Once the bond takes hold I strengthen the joint from inside using Jet acrylic (often used by the dental industry — it creates a strong bond over uneven joints and surfaces with the powder and liquid application).
I give the facial details some depth to create the illusion that the pumpkins have a thick rind. The candle is a battery operated tea light. Enjoy!