Sand-Cast Aluminium

Sand Casting is a very old method of making products, or parts of products, but is still used in industry today. An example of how it is still used in industry is the Eames Office Chair. Although this chair was designed in the 1950's, it is still made in Germany today, and remains one of the most famous products designed. The arms,back support and legs are all aluminium cast and prepared by hand everyday. The iconic status of this chair has earnt it a £420 price tag, which represents it's design genius, and the fact that this type of Product Design had never been seen before.

It is possible to sand cast small parts and attach them together. Sand casting is done by placing a mould made from jelutong or MDF in the bottom of the Cope (the bottom half of the cast) and dusting with chalk dust. This stops the mould getting stuck to the sand and makes it easier to remove. Sand is sieved over the mould finely at first, and tamped down to compress the sand tightly together, so there are no gaps. After the Cope is about halfway full, a different sieve is used, which is much less fine. Larger pieces of sand come in, but is still compressed in the same way with force. When this is tightly packed, the Cope is turned upside down, and the Drag is placed on top. More chalk dust goes on the base of the mould (now facing the cieling), and fine sand gets sieved over the Drag and compressed. When this is half way, channel plugs are inserted either side of the mould, which will later be the channel for the aluminium to fill the mould. Once these are in tight and been compressed in, the less fine sand is sieved over again and tightly packed in.