making a prosthetic-some questions

[Elm Nehmara]

I am interested in making a forehead prosthetic similar to B'Elanna Torres however I have some problems

1. I am on a very tight budget and can't afford the more expensive stuff such as plaster.

2. I live in a very small house with no basement, only two small bedrooms, 1 living room, kitchen and bathroom. I am living with my father at this time and I am sure that he wouldn't appreciate the mess made by using plaster.

3. I do not have any friends or assistants that would help me.

So I am wondering if I can use air dry clay to mold my face and either use plaster of paris or engrave the ridges into the clay to create a negative and then fill it with latex. Now if I use plaster of paris to create a positive what agents can I use to keep the two pieces from sticking together. Same thing if I just do an engraving, what can I use to prevent the latex from sticking to the clay ( It will be dry before I put it in.) Also what would be the best latex to use?

I appreciate any help.

Elm

[Klythe]

   You really can't do a life cast by yourself.  Even if you only cast the forehead you will be covering the bulk of your face in plaster.   Even if somehow you cast so your eyes aren't covered in plaster they'd be covered in some sort of shield to keep the plaster out of them.  Most likely you should be getting a full face or head cast, and whenever you do this you definitely want someone else there to make sure you are good and should your airways become blocked they can do something about it without ruining the whole cast.  You will won't have a good way of looking at your clay ridges while sculpting them on your own forehead, and every time you move a muscle you'll have to stuggle with the clay shifting with you.  Preferably someone experienced should be present, but for safety someone else has to be present, lifecasting yourself if it's even possible is just not a good idea at all.

    If you can find some friends or a local costuming or theater group, you should be able to trade favours.  "I'll plaster your head if you plaster mine, wink wink nudge nudge"   I'm trying to work out the same kind of deal here... 

    Alternatively, since latex is very stretchy, the appliance doesn't have to fit your head perfectly, and honestly your forehead moves enough that it actually matters less than you might think.   You should be able to start with a styrofoam headform (say from a wig store) and build it up with clay until it's at the same diameter as your head, then add the ridges onto that, and then cast that with the plaster to form your negative mold for the latex.  I really don't think you'll be saving much by trying to jump over the first two molds to the final one...   

   Plaster can just be cast over clay and latex an be cast over plaster without any mold release agent.  The rule of thumb is to cast hard to soft and soft to hard...  Once the plaster solidifies and hardens, you can peel away the soft clay, and you can use balls of clay to pull out any remaining globs of clay out from the inside of the plaster, since lay will stick better to more clay than the plaster.  Similarly with the latex, once the last layer has dried and fully set, it can be carefully pulled right out of the plaster.  There are some materials that need a mold release, but not these.   The two mold releases I'm most familiar with are waxes (which can add thickness which can slightly distort the interface between the two surfaces, or polyvinyl alcohol.  But as hard as plaster is, flexible materials are pretty easy to pry off of it without any of that.