Make some decisions and make some molds

Step 6: Make some decisions and make some molds

At first i had planned to use PVC for my Ice Scream Man like any good designer toy maker, I made a high temperature test mold and learned pretty quickly that i was going to end up spending more money on energy costs keeping the oven hot than i was on anything else and the cycle times of this little operation would be incredibly prohibitive.

I did some research and ultimately landed back where most DIY toy makers do, Urethane resin.
turns out if you process it in a standard silicone mold under rotation with a little bit of heat you get really good results.

The simplified version of building a silicone mold:

-spend a lot of time prepping your master as discusse din step 4 of this project
-define the parting line on your master with a clay wall
-1 important thing to note about a rotational casting mold is that it does not need vents or a gate as you will simply load material when the mold is open.
-build walls around your master
-mix up and degas your silicone and pour it over your piece
-wait
-remove the walls flip the mold and remove the clay wall being careful not to disturb the portion of the master now encased in silicone.
-coat all surfaces of new silicone with mold release
-build new walls
-mix, degas, pour second side

BOOM!!! Mold Done

The mold making process is standard and should be documented in it's own instructable
Oh look... it already is thanks bofthem