Silicone Setting Issue

Hey all!
I am fairly new when it comes to working with encapsulated silicone so I decided to watch the Character Makeup- How to Run Silicone Prosthetic Appliances video with Cory Czekaj, which I highly recommend!

Before watching the video I had always added slacker to my AB mixture and never had any setting issues. Cory mentions to add everything (color, flocking, softener) to A to prevent any setting issues. This was new to me so I decided to try it out! I added slacker to A, added my color then mixed in B. I'm using Smooth-On's Dragon Skin FX Pro and unfortunately by mixing this product this way the silicone does not set. To make sure I didn't do something else that could have affected the set I did a second test and came up with the same result. I went back to mixing the way I have been (AB + slacker)  and everything sets fine. Has anyone else had this issue?


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    Hi Sara,

    Mixing everything into part A should not cause any curing issues.  Normally the pigment and other additives are mixed into only one of the two part mixture (the thinner part) so you can save on stir time once you add A and B together.

    It's possible the mixture got contaminated somehow. Common culprits are latex gloves, latex sponges, containers or tools that are contaminated with latex residue, older material that has sat for too long, or overspray getting into the mold from other projects.

    I can't think of why it might work only when you add the slacker after mixing A and B, and not when the slacker is mixed into one component before the final mix.


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