This simple half mask of a skull, by Rebecca Burt, brought lots
of good comments this Halloween. The photo isn't clear, but it
looked great.
Basic Slush Latex 101
Slush latex, also known as mask and slip latex, is a thick
cream colored liquid with a strong ammonia smell. Unlike foam
latex, it doesn't need to be oven baked and will dry by air into
an opaque rubber-like material similar to a rubber band. This
kind of latex can be purchased at most costume stores and from
any make-up supplier including Burman, Ben Nye and Graftobian
(at various prices). Slip latex can be molded in many materials
including plater, hydrocal, and plastic molds, but for our how-to
we'll be using the easy to find plaster of paris. Slip latex is
easy to use, and this how-to will give you the simplest and cheapest
way to make a partial mask or appliance. Once you have tried it
this way you may decide to upgrade your materials or try more
complex work.
Materials
For this how-to you will need:
Sculpting
You first job is to sculpt what it is that you want to make.
Take your life cast and stick the clay to the area you're going
to work on. Sometimes it won't want to stick to the plaster, but
if you feater the edges well it will usually stay put. Start by
'roughing' your creation, that is making the basic form with lumps
of clay. Then when you have the basic shape work on making it
into the form you want and adding the detail you want. You can
use your hands, store bought sculpting tools, or anything you
have around the house that will help you add shape or detail.
Some things your might find halpful as tools are: screwdrivers,
exacto knives, pencils of different sharpness, cutlery, needles,
wire brushes, sticks, etc. You can add texture by using texture
stamps, sponges, leaves, rocks, crumpled paper, feathers, etc.
If you want a smooth surface, getyou fingers wet and smear (try
not to leave finger prints) or use the quick touch of a lighter
or candle (the black they leave won't hurt anything).
The sculpting of your creation is very important, so make sure
you have it exactly how you want it before continuing.
Making the Negative
When you are done your sculpture it is time to make the negative
mold. Use the tin foil to make a tub the size & depth (nose to
back) of your life cast (or at least large enough for the area
sculpted). Try to make the walls of the tub thick and the corners
fairly sealed so you don't make too big of a mess. Carefully use
a Q-tip of a paintbrush to coat your sculpture and lifecast with
the liquid dish soap. This will make it easier to remove later,
make sure that any plaster areas of your lifecast are coated extra
well. Mix up your plaster of paris to a yogurt-like consistancy,
no thicker or it widamage your sculpture. Pour the plaster into
the foil tub carefully, leaving a little room from the top. The
tub might leak a little but that's ok, the tub will very likely
overflow when yuou put in your scupture so make sure you have
your cleanup stuff nearby. Carefully pick up your lifecast and
press it face down into the tub, far enough to cover the sculpture
but keeping the back half above the plaster. The plaster should
be thick enough to hold the lifecast/sculpture in place, but if
it isn't keep it in place with your hands until the plater solidifies
enough. Make sure that the nose doesn't hit the bottom of your
tub or your mold could come out deformed. Let the mold sit until
it is dry, a few hours at least. After it has solidified enough
you can peel away the tin foil to help the underside dry faster.
When the mold has dried, carefully remove the lifecast (you might
have to pry a little). If any clay is still in the mold work it
out carefully with you hands or a sculpting tool. If your mold
has very find work, you may have to melt out some of the plasticine
using a lighter, oven or microwave, just be careful! Peel off
the rest of the clay from your lifecast as well, and clean it
as best you can with a little soap and water or alcohol. Now you
have a finished mold (negative) and your lifecast (positive).
It's a good idea to let the mold sit for a while after cleaning
so that you can be sure the inside is dry.
Pouring the latex
First you have to prepare the mold. Use the dish soap again,
just light coats though, and coat the lifecast and mold. Make
sure that it is just a coat and there are no pools of soap in
the negative. After the soap, carefully dust both sides with talc
or baby powder. Now the mold is ready for use.
Start out by using a Q-tip to fill the smallest areas of your
negative mold with latex. Try to get rid of any air bubbles by
rocking the mold and blowing on the surface of the latex. Now
use the Q-tip, or pour a little from your latex container into
the negative to coat the rest of the surfaces. Fill any deeper
areas of the negative that aren't part of the positive (wherever
things stuck out of your sculpture). When the mold is well coated
pour in a little more latex and rock the mold to get rid of air
bubbles. Now carefully set your lifecast into the mold and press
it down into place. Some latex should squirt out around the edges
of the mold. Sit the mold somewhere to dry and leave it to dry.
The face mask in the picture took about a day and a half to dry,
smaller objects will dry quicker and larger will dry more slowly.
The mold should be kept at room temperature to dry the best (cooler
temperatures slow the drying process). Do not bake the mold!!
Removal
When you believe the mold has sit long enough (the longer it
sits the better guarantee that it will be dry) then carefully
pry the lifecast loose and set it to the side. The latex piece
will be finished in the mold. If the piece is still wet, just
press the lifecast back down and leave it longer, the finish on
the back of your piece will be lumpy from opening, but the front
should be just fine. If it is done the latex will be rubbery and
can be pulled from the mold carefully. Work it out from tight
spots if you can, but you may have to break the mold to get it
out. Molds with many fine parts are usually only one use, so be
extra careful not to damage the latex piece. As you pull out the
latex us a little talc or powder, this will stop the latex from
sticking to itself which it will tend to do.
Once you have the piece out, dust off any excess powder and set
it in place in your lifecast. Latex pieces can deform if not kept
in the proper shape on a lifecast. You can repair any visible
air bubbles with a little latex and a toothpick, letting it dry
while sitting on the lifecast.
Note - If your mold is still good, you may notice after a few
days that it has grown mold of it's own. Don't worry, it happens
sometime when using these super-cheap materials. Simply clean
off the mold with a soft cloth or Q-tip and some alcohol and it
should be fine.
Painting
If you decide to paint your lifecast and don't have specialty latex paints, then this technique will work (but may create a gravelly look, usually not noticable though). Take whatever color of acrylic paint that you chose for your piece and put some out on a tray or piece of paper. Mix in some rubber cement or contact cement and paint this mixture onto your piece. You have to work fairly quickly, only mixing small amounts at a time, because the rubber cement dries quickly. This paint mixture works fairly well, but don't use expensive brushes with it because it will destroy the brush you use. after the surface is painted you can use normal make-up and paint to finish it off exact. For a good gory look, paint your bloody areas with rubber cement paint in red and then when it's dry paint on some corn syrup blood. It will dry shiny red (but stay a little sticky) and looks really good.
Finished
Now your appliance is done! You can use any adhesive, including
spirit gum, to attach it to your subject. Latex pieces can be
reused over and over if cared for properly. Keep these guidelines
in mind:
Good luck with your projects!
