rock - cliffs and cuttings
rock cutting behind the station
Every now and then, one sees a model railway
that represents rocks by sticking stones or slate waste into plaster. Not
surprisingly, it looks just what it is! Some modellers use flexible rock
moulds that are available on the market. Some of the are very good but
usually gaps are left between castings that never look to good. I always
form and carve my rocks from plaster and have never been disappointed with
the result.
If I am adding rocks to a shell topography
the first job is to add Polyfilla to where rock cuttings are needed. This
is shaped using a small steel rule, dental picks and a toothbrush (always
use someone else's) when the plaster is in varying stages of hardening. We
find it is often easier working with the baseboard on its side. Notice the
rock drill marks.
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 except in very dry
conditions. Even a tiny crack
will support life after a little while.
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.
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.
The rock shelter was made in foam sandwich
and then 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.
the rock shelter - notice the rock bolts
the completed cliff face
The rock faces of Cliffhanger under construction.
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
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