The world gets a little greyer every year. According to a paper published in 2014 concrete—an aggregate material made by mixing cement, sand and gravel—is the second-most consumed substance in the ...

Make a mould First you need to make a mould for your canoe -- a positive mould where the canoe is moulded over the outside, not in a hollow. Glue the foam cubes together to create a 1m x 1m x 4m block ...