List of all materials from class
Casting and Molds:
Plastic: EasyFlo Clear (PolyTek) and SmoothCast300 (Smooth-On)
Resin: Envirotex Lite (craft store or Amazon)
Silicone Rubber: Oomoo 30 and Oomoo 25 (Smooth-On)
Polyurethane Rubber: Polytek 74-30 (PolyTek) and Vytaflex10 (Smooth-On)
Concrete: Kwikrete (hardware store)
Foam: Foam-It!5 (Smooth-On)
Chalk: Plaster of Paris and powdered tempura (craft store or Dick Blick)
Paper: paper scraps
Pigments:
SoStrong Pigments (Smooth-On)
Ignite florescent pigments (Smooth-On)
PolyColor pigments (Polytek)
Colores Resin colors
Additives and other:
Mann's Mold Release 200
Universal Mold Release (Smooth-On)
Ease Release 2831 (Smooth-On)
Stik-n-Seal (Amazon, hardware stores)
Websites:
PolyTek: http://polytek.com/index.php
Smooth-On: http://www.smooth-on.com/
Dick Blick: http://www.dickblick.com/
Alternative Materials: Casting
Wednesday, April 30, 2014
Chalk Casting
Lesson: Chalk
Casting
·
Spray your mold with mold release.
·
Mix Plaster of Paris with water (4:3 ratio, or
to the consistency of sour cream/greek yogurt)
·
Add any powdered color (powdered tempura is
perfect for this, especially if you plan on using the chalk) and mix thoroughly
·
Pour into mold and tap gently against table to
settle the plaster and bring any bubbles to the surface.
·
Let cure- 1-2 hour in the mold, then let sit undisturbed
for another 4-6 hours before using.
·
After the plaster is set but still finishing
curing, it will be cool to the touch. Once it stops being cool and goes to room
temperature it is completely finished curing.
Let any remaining plaster cure and dispose of in the trash!!
Working with the castings:
·
You can embed objects into the chalk to be
exposed as it wears away.
·
You can also imbed findings into the back of the
chalk by placing them in after you cast and before the material cures. Any
findings embedded this way should have a pin or rod that extends into the
casting for stability and adhesion. Simply placing a pin back or jump ring on
the surface is too fragile.
·
You can drill into the chalk- gently!
·
You can also carve the chalk using burs or wax
tools.
·
Finish the chalk with gentle sanding- it wears
away quickly!
Paper Casting
Lesson: Paper
Casting
·
Tear your source paper into small pieces (approx.
1”) and soak in hot water to loosen the fibers.
·
Soak for at least 20min, longer for
stiffer/thicker papers. You want the paper to feel like it will fall apart when
you pick it up.
·
Place your soaked paper in the blender. Add a
little water and blend.
·
If the paper isn’t blending well, add more water
until you can get a puree.
o
Our blender is normal cooking size so you will
make enough puree for several smaller pieces.
·
Once the paper is pulped completely- you shouldn’t
have pieces of paper left, just mush- strain out most of the excess water.
·
You can place your pulp in a cheese cloth or fine
mesh colander lined with coffee filters or paper towels if it is especially
liquid.
·
You usually do not need to spray mold release
for paper casting
·
Place some of the pulp into your mold.
·
Tap against the counter to settle the pulp.
·
Place a towel over the pulp and press down on
it- compressing the pulp in the mold and wicking away the moisture.
·
Repeat until the mold is full and the pulp is
tightly compressed.
o
If you are having trouble with the layers
separating, either the pulp is too dry (add water) or not blended enough.
·
Let dry- depending on the thickness of the casting
this can be anywhere from a couple hours to a day.
·
Demold and let sit for a couple hours. This
makes sure that the areas deepest in the mold are cured as well.
Working with the castings:
·
You can’t do too much finishing work on the
paper as it starts to fray and soften at the edges. If you do need to trim the
casting, use an sharp Xacto or scissors to remove any flashing.
·
If you want more flexibility in your castings,
mix in some Elmer’s glue or PVC glue (archival bookbinding glue) into the pulp.
·
You can (slowly and gently) drill the paper
castings. The small nuts and bolts, tube rivets, and grommets are really good
for connecting. You can use cord, chain or jump rings through the holes in the
grommets or tube rivets. The protection of the metal around the hole helps to
prevent fraying and the connection coming loose as the paper softens at the
stress point.
·
For colors, it is best to use paper that is the
color you want. Remember that since you are blending the paper, if you want
multi-tone casting, blend the colors individually and mix together after
straining the pulp.
Wednesday, April 16, 2014
Project 2
Project 2:
Unexpected
For your second project, create a series of pieces that each
have something unexpected or surprising
in your use of the materials. Create 3 pieces.
Examples: Concrete is thought of as heavy- make a light
concrete piece. Rubber is flexible, use it for something that needs rigidity
like a spoon. Consider using multiple materials to achieve your goals. Foam is
considered squishy and light- make it rigid and/or heavy.
Consider incorporating metal or other materials. Think about
structure and visual appearance: How can you use those to create your surprise.
The unexpected quality must relate to the material but it
can also relate to the subject matter of the piece. Think about a knife made of
rubber or a weight made of foam, etc.
You must choose 3 different materials from the list below:
Foam
Rubber (polyurethane or silicone)
Concrete
Chalk
Paper
Plastic/Resin
Ideas/Designs: Due March 26
Project due beginning of class May 14 (final class)
Concrete Casting
Lesson: Concrete
Casting
Concrete has a very thick consistency when casting- it is
unsuitable for delicate thin pieces.
·
Spray your mold with mold release.
·
Scoop some concrete powder into a cup.
·
Add any additives such as vermiculite or sand-
do not add more than 10-20% of the amount of concrete.
·
Add water slowly as you mix.
o
You want the mix to be as dry as possible and
able to fill your mold. Think of ricotta cheese consistency. If the mix is too
wet, add more concrete. Too dry, add more water.
·
Add any powdered color and mix well.
o
Concrete doesn’t color as deeply as the other
materials. It will tint the concrete rather than truly coloring it.
o
For brighter colors you can purchase concrete
stains that you pain over the surface after curing.
·
Spoon/pour the concrete into your mold.
·
Let cure for 4-6 hours then cover in plastic
wrap.
·
Let cure for 1-2 days.
·
Demold and do any prelimanry wet sanding.
·
Wrap in damp paper towels and put in to a ziploc
bag.
·
Keep the paper towel damp, and let cure for
another 5-7 days.
·
Remove from damp paper towel and finish wet
sanding.
·
Let surface dry.
Working with the castings:
Adding metal frames or armatures can increase the strength
of the concrete.
Rather than drilling the concrete- consider embedding tubing
in the casting. You can drill concrete but you need special bits and it is time
consuming.
Wednesday, April 9, 2014
Foam Casting
Lesson: Foam Casting
·
Prepare your mold by brushing the mold release
all over the surface(s) and let it dry. Make sure to brush around the opening
you’ll be pouring into. Make sure to use the Ease Release 2831- the other mold
releases will not work!!
·
The foam expands as it cures! The foam we are
using expands 10:1. Check the bottle for this information as each foam expands differently.
·
Pour water into your mold to figure out the
volume. Divide by 10, this is the total amount of foam you need. Divide by 2 to
get the amount of Part A and Part B.
·
The polyurethane foam is quick curing, so work
similar to the plastic. Pour part A, add any color, add Part B, mix and pour.
o
You can use any of the pure pigments for color
(not the colores colors)
·
Tap the mold gently against the counter to help
bring any bubbles to the surface.
·
Let cure. You can demold after 30min, but full
cure takes 2 hours.
Safety: You must wear your respirator and gloves when
working with this material. This can only be poured during class or hazmat open
studio
The foam we are using (Smooth-On’s FOAM-iT! 5) is a relatively
rigid foam, it does have some flex, but is not squishy flexible.
The foam surface is less porous when fully contained in the
mold. If it rises out of the mold, it become a looser consistency.
Working with the castings:
·
You can drill and shape the foam with sandpapers
and files. Make sure to clean your tools well before and after using them on
foam.
·
Foam adheres to just about anything not treated
with the 2831 mold release- this makes it very easy to attach foam castings to
other surfaces or to each other with a little additional foam.
·
Test glues before using- some glues eat away the
foam (cyanoacrylates do this).
Wednesday, April 2, 2014
Casting Rubber
Lesson: Rubber
Casting
For the casting process, rubber is
very similar to the resins/plastics. We are using 1:1 ratio rubbers. The biggest
differences are in cure time and type of rubber. Like types of rubbers will
bond together- silicone rubber will bond to a silicone rubber mold.
Polyurethane rubber will bond to a polyurethane rubber mold.
We have a silicone rubber and 2 polyurethane rubbers for
casting.
Oomoo is a
silicone rubber. We used it for mold making as well. Naturally it is an opaque
lavender color when mixed and cured.
Vytaflex is a
polyurethane rubber, pale peach color when mixed and cured- it has some
translucency but is not clear. This is much more flexible rubber than our other
polyurethane rubber.
Polytek 74 series
is the other polyurethane rubber, also one we used for mold making. It is a
clear light amber color when mixed and cured.
All rubbers can be colored with any of the pigments we used
for the plastic. They can’t be colored using the colores pigments, or the
ceramic paints- only the pure pigments.
Prepare your piece or mold.
If pouring rubber into a piece, make sure all finishing is
done. This should be the last step.
If pouring into a mold, spray your mold with mold release.
Make sure the release works with the type of rubber you are using! (read the
label)
For delicate/thin castings:
The rubber is thicker than the resin and plastic. You may
want to use a disposable syringe or eyedropper to inject the mold. This pushes
the material in with greater force then simply pouring.
Thickening rubber for brush-on casting:
You can mix in some of the PolyFiber material to thicken the
rubber, allowing it to just stay where you want it to when pouring, or to be
able to brush on the material to create a hollow form. The PolyFiber does tint
the rubber- making it a lighter shade and more opaque.
To Use:
Mix your rubber as directed. Add in
PolyFiber a little at a time (half spoonful) and mix thoroughly. Add enough
until the rubber resembles icing- it holds soft peaks.
Imbedding:
The rubber cures slower, but it is more viscous than the
plastics. If the embedding material is light, pour a layer of rubber, lay the
material in, and then complete the pour.
If the material is heavy and will sink through the rubber,
you will need to do a multi-stage pour.
Connecting:
Rubber bonds to itself better that the plastic. In addition to
the other connection methods, you can also connect castings by pouring a little
extra material to connect them. Set your castings up on parchment or other
non-stick surface at the correct distance. Block off the aarea/shape of the
connection with plasticine, sculpey, or coated cardboard (i.e. anything that
the rubber will not stick to). Pour, and let cure.
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