16
Make Rock Castings
1. Make a solution of “wet water.” Mix 2 drops of liquid dish soap in 1 cup of water.
Coat inside of Rock Molds with solution and pour out excess. Wet water helps
disperse air bubbles in rock castings and acts as a mold release agent.
2. Secure Rock Molds in a level position using newspaper wads
(Fig. 47)
.
3. Shake carton of Lightweight Hydrocal for 30 seconds to mix contents. Set aside
1 1/2 level cups to attach rocks in a later step.
4. Prepare Lightweight Hydrocal using a clean, mixing bowl and utensils only. Pour
2 1/2 level cups of Lightweight Hydrocal slowly into 1 cup of water. Let stand
for 2 minutes, then stir thoroughly for 1 minute. Pour mixture into Rock Molds
immediately (working time, 5 minutes). Fill level with top of Mold, and tap gently
to dislodge air bubbles.
NOTE:
There is enough Lightweight Hydrocal to fill both Rock Molds twice and one
of the Molds a third time.
5. Let rock castings dry 30-40 minutes before removing from Molds. Clean mixing
bowl and utensils before preparing each batch of Hydrocal. Do not pour any
excess plaster down sink drain.
Install Rock Castings
1. Decide on rock placement and test fit in desired locations. Rocks look more
natural on steep hillsides with strata layers running horizontally
(Fig. 48)
. Break
some castings into pieces for rock variety and a realistic, natural look.
2. It may be necessary to cut into Plaster Cloth terrain with a hobby knife for best
fit
(Fig. 49)
. Plaster Cloth is very durable and the integrity of the terrain will not
be damaged.
3. Use the remaining 1 1/2 cups of Lightweight Hydrocal to install rock castings.
Due to limited working time (5 minutes), mix in small batches to attach two or
three rocks at a time. Mix 2 1/2-parts Lightweight Hydrocal with 1-part water.
Prepare mixture as instructed in
Make Rock Castings
.
4. Soak castings in water for 10 seconds and wet Plaster Cloth terrain where rock
will be attached. Both surfaces need to be wet.
5. Spread Lightweight Hydrocal on back of rock casting and press into place
(Fig. 50)
. Hold until setting begins or use Foam
Nails to hold in place until set. Use the Stir Stick to dab small amounts of Hydrocal around edge of rock where there are
gaps. Keep plaster off rock face or casting will lose its rock-like detail.
6. Repeat for each rock. Let dry for a minimum of 12 hours before coloring.
Rock Castings, Terrain and Tunnel Portals
Fig. 50
Fig. 47
Fig. 49
Push or Cut
Plaster Cloth
ITEMS NEEDED
Woodland Scenics
❏
Lightweight Hydrocal
❏
Rock Molds
❏
Tunnel Portals
❏
Rock Colors
❏
Earth Undercoat
❏
Foam Pad Applicator
❏
Stir Stick
Household
❏
Measuring Cups
❏
Plastic Mixing Bowl
❏
Liquid Dish Soap
❏
Newspaper
❏
4 Disposable Cups
❏
Hobby Knife
Fig. 48
