Caves are fascinating for their beauty and mystery as well as their unique wildlife. Building a model cave requires that you consider how much of the cave you wish to show, but as a general rule, you will probably want to make a visible cavern complete with stalactites and stalagmites and perhaps water pools. The basic requirement is time and space, but you can make a very interesting cave formation with relatively inexpensive materials.
Cut a length of plywood 2 to 4 inches longer than you desire the model to be when completed.
Cut the chicken wire or dog wire to a length approximately twice as long as you desire the final model to be.
Form the wire over the top half of the ball and bend back the wire so that it creates a semicircular shape with an open face.
Reinforce with a second and layer of wire, tying the two layers together with florist's wire. Repeat until the cave form will hold its shape.
Crinkle newspaper into various elongated and rounded forms and tape them to the inside of the cave walls with masking tape. Florist's wire may be helpful here as well. This will simulate rock texture.
Take a strip of the plaster bandages, also known as modroc, and dip it into warm water for a few seconds until moist. Invert the cave structure and, working from the centre out, layer the plaster bandages along the inside of the cave first until the basic texture looks good. Allow to dry.
Create a cave floor by using wadded newspaper and masking tape as desired and coat with plaster bandages.
Create stalagmites and stalactites by wrapping newspaper and tape around toothpicks, wooden skewers or dowel rods, leaving a little of the stick showing.
Press the exposed stick end of the stalagmites and stalactites into the wire frame where desired, using gentle pressure.
Wrap plaster bandages around the stalagmites and stalactites and smooth it over to form a bond and allow to dry.
Spray at least two coats of primer on the interior and exterior features of the cave model and allow to dry.
Paint the interior with orange, tan, brown or other colours.
Bring the cave top and bottom together and use bandages, plaster or gypsum cement to smooth over the gaps. Paint with grey paint by hand along the seams when done and then cover with your interior paints.
Paint the cave exterior as desired.
Before you paint your cave, take a look at various interiors to aid in your colouring and design Plaster can be messy. Wear old clothes and have a damp rag handy to wipe away excess as you work. Simulate water pools by sculpting a shallow depression on the cave floor and filling the area with quick-setting clear glue.