Creating Rubber Moulds

Last year I created some 3D models using Rhino. These were then 3D printed in wax and then cast in silver. After getting them back this year I used them to create some rubber moulds in order to produce multiples of the same piece. The rubber mould, if made correctly, will produce wax replicas of the original metal master. When the rubber mould has been created successfully, I can use the wax injector to fill the rubber cavity with molten wax. After a few minutes the wax will solidify inside taking the shape of the original piece, that is, if enough wax was injected, to gauge the pressure right it can take a few goes. When the wax replica comes out correctly I can then sprue it up and cast multiples in one go.

  • The first step is to solder a brass sprue to an area on your cast piece, preferably a flat area so no detail of the original is obscured or damaged. If the piece is made of plastic or other material then it can be super-glued to the brass sprue (although, sometimes can drift from the piece). Add a brass ‘cone’ to the end of the sprue creating a channel for the wax to flow through later.

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  • The college supplies two different sizes of moulding plates. The smaller one can hold up to 6 layers of rubber, whereas the larger one can hold 8 layers for thicker pieces.
  • I used the metal plate to trace on top of the rubber sheet enabling me to cut out 6 of the correct sized pieces of rubber. I would snip the corners off the rubber to create a snug fit into the rounded plate mould.

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  • I’d peel off the protective film off the rubber and place it face up in the plate, I’d then repeat this with the second layer. With the third layer, I’d cut out a small triangle-like shape to fit round the metal cone. I’d also cut out areas of this layer to fit around the object or cut pieces out of some rubber to fill any open areas in a design. As the rubber needs to melt and form into the shape of the piece inside, all gaps need to be filled as much as possible. Again, I’d place this layer peeled side up.
  • The fourth layer would be placed peeled side down, with another triangle shape cut out to fit round the cone. The final two layers will also be placed face down.
  • The rubber and mould is then covered by some metal sheet and placed into the heat press and closed tight. For the 6 layer mould I leave it in the press for approx. 50 minutes with the temperature at 275 Degrees Celcius. With the 8 layer mould I would leave it in the press for approx. 1 hour.
  • After 50 minutes, using large tongs, carry the mould over to the sink and rinse under cold water until cool to touch.
  • Remove the metal plates and pop the rubber moulds out of the frame and secure in a vice.
  • Using a sharp scalpel, start slicing through the rubber from each side of the brass cone, keeping the cut down the centre until you get to the piece inside, taking care as the piece could still be hot inside the mould.
  • Continue slicing down the sides of the piece until you can free the object. Then continue slicing through where the object had been, not completely cutting the rubber mould in two.
  • Once the pieces from inside have been removed, create some slices through the rubber, creating vents for air to escape. It should look something like this:

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  • Test out the mould using the wax injector. After a few minutes check the piece inside has worked. This can take a few attempts purely from trying to gauge how much wax to be injecting.
  • If you find lack of detail in the piece or bubbles it could need more vents sliced through the rubber before attempting again.

lava

Stevie

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Sense of Place – Iceland Inspiration

My latest adventure took me to the land of fire and ice, stunning Iceland. This was a surprise gift from my mum and sisters to celebrate a ‘special’ (and terrifying!) birthday. My hotel was situated right in the heart of Reykjavik, with my hotel just across the street from the iconic Music Hall, The Harpa! Needless to say, my 3 days spent here were highly inspiring and I found countless photo opportunities to incorporate into my new brief.

It was easy to get inspired with so much natural beauty surrounding me. My first day was spent exploring the cities sweet cafes and obscure restaurants, followed by a Northern Lights boat tour. The second day I explored the snowy, city gardens and quirky little shops and art studios, followed by the most luxurious experience at the famous Blue Lagoon. We entered the Lagoon around 7:30pm so by this time it was dark and you could see the steam from the warm water rise into the cold air and the stars lit up the sky, looking like a connect the dots puzzle, with Orion’s belt glowing strong and the odd shooting star flying by. The last time I’d seen the sky lit up like this was around 10 years ago in a rural town called Te Akau, in New Zealand. The final day was the most inspiring when my mother and I took the express tour around the Golden Circle. I would have loved to stay longer to truly absorb the beauty but we had a flight to catch that evening and made it back just in time! We stopped to walk between the Eurasian and North American tectonic plates, then moved onto seeing the Geysers in Strokkur, followed by the stunning Selfoss, Glacial Waterfalls with an abundance of snowy landscapes in-between.

Below are some pictures I collected on my trip which has provided inspiration for designs and samples to soon follow – Shapes within an art studio mirror (the artist apparently works on the Game of Thrones set!), the blue lagoon paving, rocky cliff faces and the Harpa music hall windows. Along with the beauty of nature – Geysers and waterfalls. I also love the mix of colours in the picture of the geyser; a pleasant mix of yellow, grey and blue.

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Whilst exploring Iceland, I found a lot of lava rock which I also found a lot of in Fuerteventura. I decided to bring some home (on both occasions) in an attempt to make my own little souvenirs. However, today I decided to create a rubber mould from a tiny piece I collected from the Reykjavik shore. The lava rock is very porous and honestly I thought the attempt would be a write off but I am very pleasantly surprised by the results and am now designing to potentially incorporate this into my work!

lava

The pieces look a little weird in this picture and I will have to take a higher quality image to show the details better but I love how organic the wax injections look! Further design work to follow shortly. Thank you Iceland for an inspirational escape! I will see you again one day.

Stevie

A little video extra of the glacial waterfalls. (Had we gone just a few days earlier on the Golden Circle tour everything would have been green!)