Injection Casting Idea

So guys, from what I have gathered I seem to have an idea as to how I am going to go about injection casting a full head/part bust silicone mask. I am just looking for somebody to review my idea, to see if it would be the correct method. I also would like to be able to add some burlap or elastic mesh into it and from the way I have drawn this method out I am not quite how I would add it.
Here is my sloppy paint idea, I apologize for my novice attempt.
Is this sort of along the right lines?

You're going to need some vent holes added to your mold, or if you go the silicone, with a fiberglass jacket mold, you'll have to add some to your resin core some how. What will you be casting this out of? If it's something soft like silicone, going with just a fiberglass mold does the trick.

I would be using silicone. So if I am using silicone I wouldn't need a core? As opposed to the injecting idea, my other idea was to pour silicone in the mold and roll the mold around so that an even layer gets on all surface areas, and dump and repeat until it is thick enough.

What pitchforknumb was saying is that the silicone used to mold with is unnecessary.


Silicone molds and injection is a big NO. Silicone is very soft and if you put pressure upon it (while injecting for example) even with a fiberglass mother mold the fine details can and will shift. I know from first hand experience.

Brushing the silicone in, or trying to slush cast it, also isn't ideal. Getting an even thickness isn't as easy as it seems.


Here is a quick run through of what I'd do. I've got quite a bit of first hand experience with silicone mask making and prosthetic work myself and this is how I go about it.

I would start by making the core out of epoxy and glass, hollow of course.

Sculpt your design and then mold with epoxy and glass just like the core, being sure to bolt the mold and core together for a perfect fit every time.

Demold and remove the clay. You should have negative space between the core and mold. This void is where the silicone will eventually live.

Examine your mold and core, and determine the best injection location. I always go in through the core for silicone pieces. I normally inject with the mold upside down and the spout coming out at the top of the head. I like to drill the bleeders into the core but some designs you just can't. Doing a test run will show you where you need them.

Once its all sorted just inject your silicone, let it cure, and you should have a perfect piece.

SlipKnot said it perfectly. You never want to inject into a soft material. Just to add on SlipKnot, make sure to make some touch down spots on your core, so your core and mold will be aligned perfectly.