Hydrocal is a product of U.S. Gypsum and can be
purchased in some Hobby Shops, Cement and Ceramic Supply Stores. It has great strength, much more than plaster and reproduces detail
to a very fine degree. Another advantage of this product is the relatively low
cost. A 100 pound bag is less than twenty dollars and can be used to build
scenery as well as creating structures and assorted detail parts.
To begin the process, draw the building sides
(to scale) on a piece of paper then tape the paper to a sheet of glass with the
drawing against the glass. Turn the glass over so you are looking through the
glass at your drawing. Using rubber cement, glue strips of 1/8 inch strip wood
over the outside lines of the drawing and glue blocks of 1/8 inch thick wood
where the doors and windows will be. It is important to make sure the openings
you are creating are the right size for the door and window castings you plan to
10 to 15 minutes for the rubber cement to dry, then using a cheap disposable
brush, “paint” the glass and strip wood with a liberal coat of petroleum
jelly. The jelly will make it easier to remove the Hydrocal from your mold.
paint stirring stick, mix the Hydrocal with water in an old butter tub. Hint:
hot water seems to cause the Hydrocal to harden faster while cold water slows
the setting time.
the Hydrocal and water until you have the consistency of ketchup. Pour
the mixture into the mold and use the stirring stick to scrape along the strip
wood to level the mixture with the top of the mold. Allow the Hydrocal to dry
for about 30 minutes and remove the strip wood and the structure side from the
glass. Turn the structure side over and use a metal ruler and the back edge of a
hobby knife or a dental pick to “carve” brick or rock detail into the face
of the wall. To make the assembly easier, bevel the corner edges to 45 degrees
and glue the walls together. If your joints have a small gap, just mix a little
more Hydrocal and fill the joints, then add the carved detail once the joints
have dried. As the Hydrocal dries, it gets harder and is more difficult to
carve. If you find yourself in this situation, spray some water on the wall and
the surface will soften making it easier to carve. After the walls have been
assembled, color the structure with acrylic paints to the desired color, then
apply a greatly thinned coat of acrylic gray or white to simulate mortar. Apply
this as a “wash” and immediately wipe the excess “wash” off the surface
with a damp paper towel, leaving the mortar color in the joints between the
stones or bricks.
the doors and windows to the desired color and install. Build the roof using
card stock, styrene or the material of your choice and apply shingles or
"rolled roofing” made from masking tape glued to the roof and painted
with weathered black. Add details to the outside of the building and surrounding
the figure below for a diagram showing one side of a sample structure drawing.
Note the gray areas where the doors and window will be. Click on the image
to see a full size version of the drawing.
to Clinics by Paul