How To Sculpt & Mould Silicone Prosthetics

Hello again Varlings, I've had a lot of requests to do a quick tutorial on how to make full-face silicone pieces.

The products and equipment I'm listing below are what I used, and there are other options available, but please keep in mind that sulphur (a la ammonia) will stop silicone from curing ever (i.e., it will be a sticky, gooey mass for all of time), so if you elect to use silicone you will need to avoid any products containing sulphur, any equipment or moulds that may have been contaminated, and rooms that have latex or latex fumes in them.

PRODUCTS

  1. Sulphur-free clay or plasteline. I used Chavant La Beau Touché.
  2. Solvent for your clay. For La Beau Touché I use Zippo lighter fluid.
  3. Dental separating medium
  4. Isopropyl alcohol (ideally 99% proof)
  5. Beeswax
  6. Moulding cement or plaster. I used UltraCal 30 with Cast-Aide fibres (optional).
  7. Platinum silicone. I used MouldLife PlatSil Gel 10.
  8. Paints. I used Skin Illustrator inks.

EQUIPMENT | TOOLS

  1. Clothes that are protective but that you don't love
  2. Sketchbook and stationery
  3. Sculpting tools
  4. Various paintbrushes that you're willing to part with
  5. A sacrificial toothbrush
  6. A chip brush
  7. A tub (to be filled with warm water)

How To Sculpt & Mould Silicone Prosthetics

METHOD

I start by sketching my concept out in 2D before beginning my 3D sculpt to help me visualise the forms I want to create when the piece is photographed, and knock out where any flat areas might be once it's in that medium. It's worth doing a lot of sketches of different ideas and from different angles to discover new things and see what does or doesn't work.

How To Sculpt & Mould Silicone Prosthetics

If you're sculpting for a face it's very beneficial to have a positive head-cast or face-cast to sculpt on. It really helps if the cast you have is of your actor/model/self, but generic ones can be purchased if that's not an option for you.
The positive I used is made of Ultracal, and the negative was made with alginate and plaster of paris off my live model, Amy. I plan to do a tutorial on this in the future, but if you elect this option, PLEASE ensure this is done with utmost care and consideration, and with the present instruction and guidance of an experienced professional. Youtube videos are often lacking vital safety information and the last thing you want to do is hurt yourself or another. And please don't put plaster or cement on yourself or anybody else, as they heat up scarily when curing!

How To Sculpt & Mould Silicone Prosthetics

If you have your cast, you can begin sculpting. Since this piece was going to be cast in silicone, I used a sulphur-free plasteline, La Beau Touché from Chavant, which is my preferred clay for soft organic sculpts. I'm also a big fan of Monster Clay by Monster Makers, particularly for more rigid sculpts like scales, horns, et al. I would encourage you to experiment and find your own favourite.
I was taught to sculpt by using lots of little pieces of clay to build my shapes, which works brilliantly for me. Remember to tilt and rotate your sculpt often see how the shapes are forming. This is a 3D object, so there's no use in it only having one good angle.
You can get all sorts of textures by layering different tools, different ways of using tools, and even using solvent. It can be a fun experiment.
If you need to smooth edges down nice and thin (especially on pieces like this where we will want to blend seamlessly into the skin), use your solvent with a victimised paint-brush to blend it out.
Be aware of areas that might be overhangs (such as pointed noses), as this can affect or even break your moulds!

Once your sculpt is done, it's time to make your negative mould. Start by very gently coating your sculpt with a release agent so your moulds don't cement themselves together. For good measure I used dental separating solution, followed by bees wax thinned with alcohol. Time to put on some gloves and an apron if you haven't already!

My negative mould is made from UltraCal 30, but please follow the safety instructions and method of use for your particular stone or plaster, and coat your sculpt gently with it, being sure to try and remove any air bubbles or hollows. I used a chip brush to manipulate the stone and keen it tidy, making a flat edge on top so that the mould could comfortably sit on a table. This mould also has handles added to make it a little bit easier to open.
Leave it to cure per the instructions.

Now we have a two piece mould: one piece is the positive of the face; one is a negative of the sculpt. When the clay is removed they will have a gap between them, which is where the silicone will go later.

How To Sculpt & Mould Silicone Prosthetics

How To Sculpt & Mould Silicone Prosthetics

If you used dental separating medium, which is water soluble, leave your mould to soak in a tub of warm water. It should float off, but sometimes they need a little longer or a bit of encouragement.

Once you have your mould open, remove the clay, and check for any bubbles, cracks, or other flaws you need to repair. Once it's done, you can start running your silicone. You'll need to follow the instructions for whichever silicone you elect to use, and vary to suit your needs. This particular pull was done with Mouldlife's Platsil Gel-10, tinted with silicone tints for a milky skintone, and with a good deal of silicone deadener (50a:50b:130d ratio) added to the mix to keep it soft, fleshy, and weighty (rather than stiff and skull-like).

How To Sculpt & Mould Silicone Prosthetics

Once your silicone has cured and been pulled from the mould, it's painting time! I used Skin Illustrator's alcohol-soluble inks in an airbrush for this, for its translucency and longevity. It has a really lovely, natural look about it and layers well. Personally I find it most natural to paint using thin layers of primaries to layer colours, rather than pre-made skintone products. It gives you lots of subtle variations and imperfections that keep it looking more realistic. Don't be afraid to add spots, freckles, pores, rosacea, and other "flaws" that make your skin more believable.

How To Sculpt & Mould Silicone Prosthetics

I haven't covered the application process in this tutorial (it gets pretty long), but this is how the piece looked when applied, completely un-retouched (not even cropped or toned). Unfortunately my model had a localised reaction to the adhesive used, and it had to be lifted off under her right eye before these photos for her comfort and safety. Big thanks to my lovely model, Amy, and to Alastair and Scott (who taught me) for the photos. If you want to develop your sculpting and moulding skills more, don't hesitate to take some classes and practise! I studied at ACMUSE and have never looked back.

How To Sculpt & Mould Silicone Prosthetics

How To Sculpt & Mould Silicone Prosthetics

How To Sculpt & Mould Silicone Prosthetics

Got a Question? Want me to cover a certain topic? Leave me a reply below.

Until next time, SEW SAY WE ALL!