8
8. The masters are
stuck to the bottom
of the cup with
hot glue before
pouring heated
ComposiMold.
9. The filled mold
box. Bubbles near
the surface do not
affect the detail of
the mold.
10. The paper cup is
simply torn away to
release the mold.
9
10
Ordinarily, the raised boards on the crate would be undercuts
that would lock the master into a conventional silicone rub-
ber mold, and certainly into a stiffer urethane mold. The cured
ComposiMold flexes enough to release this master easily (11).
The detail from the crate can be seen in this picture of the mold.
To test ComposiMold with resin casting, I obtained some
EasyCast clear casting epoxy from a local Michael’s Arts and
Crafts, along with other materials (12) that I used to cast the bar-
rel and crate in epoxy. Items include the EasyCast epoxy, sticks
for use as stirrers, the mold, a paper mixing cup, and two medi-
cine cups for measuring the epoxy. The EasyCast instruction
specify that the cups cannot be waxed or otherwise coated.
The two-part epoxy was measured and mixed according to the
package directions. If I were to repeat this demonstration, I
would not use the EasyCast. It requires a two-step mixing pro-
cess and the cure time for castings of even this modest size was
measured in days rather than minutes.
The inside of the mold was coated with cooking spray as mold
release. The mold was placed on newspaper before filling, to
protect the table surface (13).
The finished reproduction crate (14) has been given a coat
of gray primer so that the otherwise clear casting could be
photographed.
A sister product to ComposiMold – PowerMold – is more firm
and is capable of making two-part molds by freezing the first
half of the mold before pouring the second half and then
refrigerating the whole to accelerate cooling. ComposiMold
is working on a product specifically for plaster casting called
ReMold; contact ComposiMold for availability.
More information and videos on ComposiMold and PowerMold
can be found on their website:
Easiest way to make molds - 6
MRH-Jan 2014
