How to create plaster molds for ceramics
Creating a plaster mold for a ceramic Jenever Jar
A typical souvenir from the Netherlands is a piece of (Delft Blue) ceramics, typically in the form of a windmill, wooden shoe, etc. Dutch Souvenirs is a project about making the concept of a modern-day souvenir. The project has been organized by the EKWC in 's-Hertogenbosch, who have invited 41 Dutch and foreign designers and visual artists to develop a new vision of the Dutch souvenir.![Jar in CAD](../photos/jenjar-cad.gif)
![Jar in CAM](../photos/jenjar-simulation.gif)
The (smooth) bottle in CAD, and the machining simulation in DeskProto.
One of the participants of the project was Ben Oostrum in Rotterdam. MNO has found inspiration in local food and drink, as in their experience many memories of foreign travel are linked to tasting typical local products. A typical Dutch drink is Jenever: an alcoholic spirit distilled from grain. Since many centuries Jenever is sold in typical brown ceramic jars: the challenge was to merge this traditional crafted shape with now-a-days design-expressions.
![Half bottle foam model](../photos/jenjar-schuim.jpg)
![Detail foam model](../photos/jenjar-schuim-detail.jpg)
Foam models used for creating the ceramics mold.
MNO has found a surprising answer to this challenge: they transformed the traditional simple geometry of the jar using modern 3D computer technology. A 3D CAD design of the traditional bottle was imported in DeskProto and toolpaths were generated on an extremely low resolution. So low that every toolpath can clearly be recognized. For any other DeskProto user this would mean an unacceptable low surface quality, however in this project it was done on intent.
The resulting jenever jar has been called "Low-Res".
The toolpaths were used to machine a bottle model in foam, using an over-sized block: see the illustration. By filling such block with plaster it is possible to create a mold for (half of) the new jar.
![Three parts of the jar mold](../photos/jenjar-mal.jpg)
![Inside detail of the jar mold](../photos/jenjar-mal-inside.jpg)
The plaster mold, used to produce the jar, and the mold seen from the inside.
Ceramics is a nice material for creating hollow products. "Normally" one needs a mold with a core in order to create a hollow product, however not with ceramics. Here you can use a mold made of plaster, defining only the outside of the product. Fill this mold with a fluid slurry of clay and water and wait some time. As the plaster absorbs the water, a thin layer of clay will be deposed on the mold surface. After some time, when the layer is thick enough, the rest of the slurry can be poured out, and the clay part can be removed from the mold to be baked.
As the mold halves in this case were created using three axis machining, it was guaranteed that no undercuts were present.
![Top of a bottle](../photos/jenjar-detail.jpg)
![Series of bottles](../photos/jenjar-bottles.jpg)
The resulting Jenever Jars: great Dutch souvenirs !
The resulting jars surely are conform the expectations: clearly connected to the traditional product, still having an expression that gives far more value than 'just another souvenir'.
The bottles have been presented at the Spazio Consolo fair in Milano, Italy.