How to cast the Chimney Block

The outer mould used for casting chimney block and chimney is slit from top to bottom. It is held together by cords. The inner tube is  longer than the outer tube so that it is easy to pull it out. 

The cement mix is filled in and pounded. The short pipes are inserted when the cement stands below each hole.

Straps of bicycle tyre are wound around the short tubes to make them fit into the holes in the outer tube.