My working process began with making metal shapes out of brass wire and copper tubing. The aim was to create a closed structure with various openings to inflate a balloon inside and test its reaction to the confines of the form. The balloon expands and escapes through the openings of the metal cage, creating unique and voluminous bubbles. Each balloon behaves differently and different volumes are created depending on the metal structure.
When the balloon is inflated, the openings in the metal cage create a lot of pressure. This makes the balloon very brittle and tends to burst quickly at these points. These pressure points must be carefully polished to make them as smooth as possible.
It is impossible to inflate the balloon in the metal mould alone, as it takes at least four hands to stabilise the metal mould and the balloon during inflation.
Wondering if there was a way to inflate a balloon other than blowing air directly into it, I started experimenting with the vacuum pump.
I found a used vacuum pump from the Inselspital in Bern at a flea market.
Looking for an airtight container, I found one in the used glass collection. Empty cucumber jars from Migros.
I used the lids from the jars and adapted them so that they had two openings. One to suck in air and the other to connect the jar to the vacuum pump. The principle was simple: when a vacuum was created in the jar, the pressure caused the balloon to inflate.
I drilled two holes in each of the lids. On the lathe I made a thread out of steel tubes. These were inserted into the holes in the lids and secured with nuts. I sealed the whole thing with wax.
I then attached a balloon to one thread of these lids, sealed the jar and connected the vacuum pump to the second thread with a rubber hose. By slowly adjusting this procedure, I was able to create such an effective vacuum that the balloon inside the jar was 'pulled' into the metal structure. Using an earplug, I was then able to seal the opening in the lid airtight. The rubber tube was sealed with an Ikea clip. This allowed me to disconnect the rubber tube from the vacuum rail and the vacuum remained in the jar, allowing the balloon to remain inflated.
With this process, I had found the solution to inflate the balloon inside the metal structure in a controlled way.
My next step was to test other materials instead of air. First I did a test with water. I placed a funnel filled with water at the air intake. When the vacuum pump was switched on, the water was sucked into the balloon, filling it. I sealed the jar airtight and unscrewed the lid. The water-filled balloon hung from the metal structure on the lid.
The balloon was removed after the epoxy was poured, leaving a voluminous, colourful object in epoxy encased in metal. In order to customise the resulting objects, I had to find a solution to reduce the weight. My process allowed me to fill the balloons with epoxy, but my aim was to make them hollow in order to use as little epoxy as possible and obtain the lightest objects possible.
My next process of experimentation began with research into roto-moulding techniques. This is a type of moulding that allows you to create hollow objects by constantly rotating the mould around two axes.
Using what I could get my hands on, I turned my parents' barbecue into a roto-moulding machine by being able to rotate objects in one direction. The result was semi-hollow objects, but some parts were too thin and unstable, but the weight of the parts was already reduced.
To refine my casting results, I decided to build a roto-moulding machine that rotated around two axes. It was made entirely from leftover materials. I used the motors from my parents' barbecue, an old wooden wine crate and an old bed frame as the structure for the machine.
I placed the barbecue's motors on two axes, one of which rotates using rechargeable batteries and the other connected directly to an electric circuit. With this machine I was able to create completely hollow objects.
