I made this brooch as an 80th birthday present for my Gran. I came up with the idea of making a brooch involving some kind of planet design. It took quite a few revisions, but eventually I came up with something that I was happy with.
The construction involved CNC milling, silicone mould making and pewter casting to create the finished brooch.
After seeing this article on Hackaday describing an easy to make silicone casting material I knew I had to give it a quick go. The photos here show the results of making a mold of a polymer clay heart and then making a heart shaped ice cube from it.
Oogoo is basically equal parts corn flour and sealant, mixed into a white goo. This Instructable has all the details for making Oogoo and fully documents its many uses.
Mixing Oogoo takes a bit of effort, I used a cardboard tub as a container and an old paintbrush handle to mix with, this probably made it more difficult than it needed to be but that’s what I had to hand.
Once mixed, i found it quite difficult to spread over my heart form, next time i plan to wear latex gloves and shape it by hand.
Even with my shoddy mixing, crappy tools and less than ideal spreading technique, I ended up with a usable mold in around 2- 3 hours. To test it out, I simply filled it with water and froze it for an hour or two.
As you can see, the Ice heart isn’t perfect, but it’s pretty close. A definite success!
In future, if I need to make a mold for any reason, Oogoo is going to be my first port of call, its quick, cheap and absolutely stinks of vinegar. What more could you want?