rock - cliffs and cuttings

Rock

rock cutting behind the station

The rock cuttings were carved in dyed Polyfilla.  We established the angle of rock strata in the area and colour. This is a technique I know well, having carved several feet of Canyon for the museum layout at Golden after attending a master class at the Smithsonian. I sculpt the Polyfilla when it has half cured. I use a six inch metal rule to form the strata and then texture it with a toothbrush (always use your wife's). Small details, including rock drill marks are added using dental picks.

Glenthorne Cutting (the rock drill marks can be clearly seen)

It is important to remember that plants will find a foothold in the most tenuous of circumstances. Even a tiny crack will support life after a little while.

Frocks

photo Mario Rapinett

This is a method developed by Mario Rapinett (aka Big 'M'). We have used the method with great success.

Materials

• Old upholstery foam: This is easily obtainable from your local upholsterer. The reconstituted chip foam is not normally the one to use except for 'special effects'.

• Plasterboard (drywall) premixed joint cement ( sometimes called Topping coat ). Mix with a bit of water to give a cream consistancy.

• hot glue gun

Tear up the foam to suit. Strata can be made using a household saw. Bits can be torn out at will.

photo Mario Rapinett

Glue bits of foam together using hot glue gun. Paint with a couple of coats of diluted joint cement which fills the foam pores.

photo Mario Rapinett

When dry, paint under colour with matt plastic emulsion. Finish using weathering powders.

photo Mario Rapinett

For building the cliffs on our harbour module, I have used a modified version of this technique. The North Devon/Somerset cliff are very specific so I had to find the right way to do it.

Being concerned with weight, we used blue foam, normally used for building composite aircraft. Having stuck the lumps in place with a hot glue gun, the shape was obtained using an electric drill with a 3/8" bit. It is about the messiest job I know and it is not a good thing to do on a windy day! For days we will find blue foam granules, in the toilet, sofa, corn flakes and cat!

punishment of foam with a 'Black and Decker Devon cliff maker'!

the cliff ready for coating

Once satisfied with the shape, the cliff is then coated with Polyfilla. This we mix to a consistency of double cream and brush on in the direction of the rock strata. We use a very short bristle brush for this ( a 1" throwaway cut down with scissors). When nearly dry, the Polyfilla is again brushed to knock off any nibs.

The surface treatment of the cliff. Some work is still needed on the tunnel portal.

After a wash with thinned brown emulsion. There is still much carving and detailing to be done. The tunnel entrance will be fitted with a concrete rock shelter. - click on image to enlarge

The rock shelter was made in foam sandwich and the exterior varnished prior to coating with a thin layer of Polyfilla. Shuttering marks were made using a 6" engineers rule. One corner shows a re-enforcing bar that has frosted and broken out. This was a common problem with early concrete structures. The rock bolts (Grandt Line) can clearly be seen.

click on image to enlarge

the completed cliff face - click on image to enlarge