First Latex Run Ever.

Well as the title says. I just ran a first ever batch of foam latex. What a perfect disaster that was. I would like to ask of you seasoned professionals what advice can you give looking at these pictures...
First. I think I over whipped the latex a bit. It didn't flow but was more like egg whites foam, so there is that. I baked the foam for 4 hours at 75°C. It was a standard batch of Monster Makers latex. I used composite molds. Plaster/Silicone.
At first I baked it for 2 hours and had to restart for another 2 more since it was still too "raw". However, I got water in my molds after taking out the piece. I suspect condensation and steam problems. Is there any way to prevent this with the silicone jacket, or do I have to go for all plaster molds?
Here is the result. I will be grateful for any advice.


  • Steam buildup can be a problem.  One option may be to bake it at a lower temperature for longer (monster makers suggests around 71C in their instructions).

    I also found this suggestion for addressing steam collapse in composite molds:
    "In non-porous material used to make a mold, foam does not stick well to the side of the mold and often results in shrinkage or ‘steam-collapse’ of the foam. Use permanent spray glue to make the foam hook on temporarily to the inside of the mold. The glue will not remain in the mold or on the foam piece."
    Anyone else have advice for baking foam in composite molds when steam is an issue?


  • Hey Chris, thanks for the advice. It helped me a lot. I kind of messed up the second run myself by adding the gelling agent the wrong way, and my foam didn't gel properly. Still, I baked it just for educational purposes, and it turned out much better. Just in sake of those who will stumble upon this when learning like me, here are the pictures. I used a hairspray for the silicon parts of the mold and mold release for the plaster parts. It seems to have worked like a charm. I drastically lowered the temperature to 55°C and baked for 5 hours. I might bake for 8 the next batch slashing it further down to 50 or even 45°C. The longer and lower seems to do the trick for silicone. I also adjusted the whipping schedule a bit and got runny foam instead of the fluff I had last time. I guess third time will be the charm.
  • Glad you are getting better results!  Hopefully the 3rd run turns out perfect!

  • Hello everyone!!!
    Do you have any detailed tutorials for using latex? I’m also interested in making large scale sculptures, so do have any idea what materials I can use without using mold?
    A lot of gratings from Montenegro,
  • edited August 2021
    If you mean regular liquid latex we would need more information about what you want to do.  

    If you mean foam latex, we have a great course on running foam latex which should help get you started!

    For making large-scale sculptures you have a lot of sculpting material options.  Everything from clays to foam.  I assume by "without using a mold" you mean you would like whatever sculpting medium you make the sculpture in to also be its final material?   So that would rule out clay.    I would need more information about what you would like to do to provide anything more detailed.

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