How to make a faux boulder for shop displays or for use in the garden as a large garden feature.

To make a faux boulder I would advise you to first make a miniture one out of modelling clay or go to the beach and pickup a pebble from the beach to use as a guide when making the faux boulder.

Take one large block of polystyrene or glue sheets of polystyrene together to make a block of poly. Glue poly together with contact adhesive.

Carve the block into a rough shape using various hand saws, and rough sand paper.

Cut out a hole in the bottom of the shape and fill it with resin to make it have a heavy base and this will make it stand up by itself and not fall over.

Coat the polystyrene in layers of paper mache using water proof PVA, must be water proof PVA and not the standard PVA. Coating the polystyrene with water proof PVA and sand is also effective. You can also coat the poly with quadraxial fiberglass and jesmonite AC100 which is what we did on this project. Adding a few layers and allowing it to cure before finishing the top layer with a coloured jesmonite. To colour the jesmonite use iron powder mixed into the jesmonite. Once the resin is cured use sand paper on the surface to make a smooth finish and remove any brush marks.