There are a
lot of different brands of mold material, each with different
properties and costs. They all basically work the same. I use
smooth-on because they were in the right place at the right time
for me. Thanks, Francis Lestingi. Do not consider my use of this
product line as an endorsement.....but it does work.
You need to first start with a level work surface and a model.
In this case, I have a small (aprox 3" wide) wood carving of a
Nantucket basket. It is sealed with a lacquer sanding sealer and
two coats of high gloss lacquer. The mold rubber is very
aggressive so the pattern must be coated with a parting agent. I
first apply 2 coats Butchers Wax. Let each coat dry thoroughly
Here's what you need.....
Next I need to form a containment for the mold....in this case,
I just cut out the bottom of a deli container. Next I roll out a
"snake" with modeling clay (it can't contain sulfur) and apply
it to the rim of the container.
I then center it around the pattern and press it down which
pushes the clay to both the inside and outside of the
and spread it smooth with a finger.....both inside and outside.
spray on another parting agent and brush it around to be sure
all surfaces are covered.
Let dry for 10 minutes. Then spray another light coat and let it
Next, mix equal parts of the mold rubber and stir completely (in
this case a half cup each)...the two parts are different colors,
so mix till it's consistently blue.
Now, I pour in about 20% of the rubber and tip the mold so that
the rubber flows around the entire model.....this will prevent
air bubbles from forming in tight places.
Then pour in the rest. To remove any remaining bubbles I just
tap the base of the mold with a rubber mallet for about 4 or 5
minutes.....or till the bubbles stop surfacing.
The rubber cures in about 6-8 hours.
If everything was done right.....Please God....please.....you
have a perfect mold of the original casting. (The prayer was for
this to work cause, if it doesn't.....you could loose the mold
AND the pattern)
Here's the two part plastic....I get the best deal on this stuff
at Dick Blick (about $20....and I'll get about 50 castings).
You'll also need a mixing cup and two small measuring cups and a
popsicle stick for stirring.
Spray the mold with the release agent and let dry for 5
minutes.....don't over spray and don't spray anywhere near where
you will be painting.....boy, ya wanna see fisheye????
Mix equal parts of part A and B....Thoroughly!!!!!for about a
minute (it'll start to feel warm) then pour it in starting at
the lowest point. Hey, if you are gonna pour one.....why not
It will start to "bloom" in the deep areas first.
Stuff cures in about 15 minutes (it's still soft so place it on
something flat for a while).
Before you can paint it, you must clean off the parting
agent....I wash first in terps and then isopropal alcohol
(rubbing alcohol). This plastic is not UV safe so I spray a coat
of Krylon Fusion then size and gild.
I'm happy that some will put this sxs to good use.
Happy Molding and Casting!