Silicone injection two part mould

Hi guys I'm just starting out and have been scratching my head over where to drill for my injection point. My piece is of a typical zombie brow but the design stretches over the nose and stops at the top lip. The sculpt was quite thin around the nose area, it's moulded in grp. I'm just unsure wether I should drill it for the nose area or at the lip? Or wether it matters? Will the silicone still flow to these areas?

Thanks in advance 


  • Ideally you want the injection point away from any important details.  It's hard to say where you should put an injection point or bleeder holes without seeing the mold.

    The silicone will flow where gravity allows it, and your main challenge there is preventing pockets of air from building up that prevent the silicone from flowing into sections of the mold.  This is why small bleeder holes are often used to allow air (and some silicone) to escape until they are plugged.

    Also keep in mind that the sprues from the injection point and bleeder holes will need to be trimmed away from the cast piece.


Sign In or Register to comment.