We were asked by the local Marine Conservation Society to make two beech trommels to be used during their monthly beech cleans. Basically they are stainless steel mesh drums into which you shovel beech sand. When they are rotated the sand falls through the mesh and the plastic nurdles and rubbish is left behind in the drum. The trommels were developed and designed by the people at nurdle.org.uk/. There are a really effective way of demonstrating how polluted our beaches are.
What are nurdles?
Nurdles, the colloquial term for “pre-production plastic pellets”, are the little-known building block for all our plastic products. The tiny beads can be made of polyethylene, polypropylene, polystyrene, polyvinyl chloride and other plastics. Released into the environment from plastic plants or when shipped around the world as raw material to factories, they will sink or float, depending on the density of the pellets and if they are in freshwater or saltwater.
They are often mistaken for food by seabirds, fish and other wildlife. In the environment, they fragment into nanoparticles whose hazards are more complex. They are the second-largest source of micropollutants in the ocean, by weight, after tyre dust. An astounding 230,000 tonnes of nurdles end up in oceans every year.
There is a very good video, and detailed drawings describing how to make the main frame and the drum , that you can see by clicking on this link. However there are very few instructions for making the stand. As a result we re-designed the frame a little, and made 4 wooden legs that are bolted directly onto the frame as in the diagram below.
The aluminium frame is made in pretty much the same way as shown in the video. The wooden legs are made from some durable solid timber, like tanalised pine, or perhaps oak. Each leg is made up of two pieces of timber, glued and screwed together to form an L section and tapered towards the bottom. 30mm holes are are drilled into both side of the legs for the captive nuts, and 8mm holes are drilled from the top to meet the holes in the sides. After the corresponding holes have been drilled in the frame, the legs can be bolted to the frame.