Making Artificial Rocks
(c) 2009 Some Rights Reserved
by Tom King
Attach heavy gauge plastic sheeting behind the rebar. Use wire ties to pull the plastic up against the rebar to prevent pooling of concrete behind the rebar. Be careful not to rip the plastic. Duct tape can be used to cover tears and holes.
Chicken wire makes a perfect framework for the surfaces of artificial rocks. It is shapable, easily cut and quickly attached to the rebar framework. Once all the surface of the structure is covered with chicken wire, go back and tweak the shape a little. Make boulder shapes, cracks, crevices and ledges as you go. Use your creativity. You can even create artificial tree stumps, fallen logs and other natural looking bulky structures.
Next, cover the large flat areas with aluminum foil. Do not crumple the foil, but wrinkle it just a little bit and then spread it over the still wet ‘rock’ surfaces and press down firmly as shown in the picture. The foil will give the ‘rock’ surfaces a natural texture.
After about 5 minutes, remove the foil and use the edge of the trowel to etch a few cracks into the concrete and to trace seams and layers between separate rock shapes. This takes a steady hand, but don’t make the lines too straight either. Vary depth and width of surface striations to imitate features of natural rock. Lightly brush the rock surface with a paint brush to remove concrete crumbs and create a weathered look. Allow the concrete to set overnight before putting weight on it.
This is one of the exhibits at Tiger Creek Wildlife Refuge that Billy designed and help build (below). Tiger Creek is home to a large collection of rescued tigers, tiger cubs and other big cats located just north of Tyler, Texas. Tiger Creek is a not for profit organization providing rescue services and shelter care for tigers and big cats.
These tigers below are enjoying the summer sun sprawled on the waterfalls and rocks built by Billy and the volunteer crew and Tiger Creek staff.
This next exhibit was built for a Tennessee zoo by, also by Billy Williamson. The black bear in the exhibit enjoys the waterfall and stream in his new home.
Note, there is not a single loose item in the picture below. Chimpanzees love to throw rocks and loose objects. Billy's knowledge of chimp behavior led to this design in which everything in the river is part of a single piece of concrete, sculpted and staied to look like an ordinary stream full of rocks and deadfall trees, but without the hazard to keepers and visitors of having a loose rock heaved at you by a mischievous chimp.
Photos (c) 2009 by Tom King, Tiger Creek Wildlife Refuge and Billy Williamson (All Rights Reserved)