Sculpting Head Core in Silicon Mask Making Part 2: Finishing the Epoxy & Fiberglass Mold

Brian LeBrian Le
edited October 2021 in Fabrication
I've finished part 1 and right now I'm taking Silicon Mask Making Part 2: Finishing the Epoxy & Fiberglass Mold. In these photos seen here (Removing the Core from Side B ) part of course, there's a head that appears to have clay sculpted over it. Do I need to use a clay that will remain soft throughout the mold making process? Or can I use WED clay that has been completely dry, set, and rock hard? Does the WED clay need to be rock hard for this course? Do colors of clays matter? I don't think I can find a WED clay the same color as the salmon hue the instructor is using.

 At the bottom of the neck there's an opening where you can fit a 2x4 block in as well as some around the neck to help give the C-clamp leverage. What is that head covered in clay called? In the course, the instructor just calls it a "core". Is the exact kind of "core" he's using absolutely needed for completion of course? Or can it be made with WED clay?

I worry that clay will be too brittle for the C-clamp and will crumble or crack. If it is too brittle, can the WED clay's neck opening be fiberglassed or something so that it can withstand the pressure of the C-clamp? 

Post edited by Brian Le on


  • Chris EllerbyChris Ellerby Los Angeles Admin
    edited October 2021
    You can use WED clay, but if it has firmed up it may be more difficult to remove the mold from around it, so you may need to soak the mold to soften things up after you have made both sides.  The color of the clay does not matter.  Different clays have different colors, sometimes the color can help identify which formula or firmness the clay is.

    The sculpt is done on a core.  It's called the core because it will also be the core of your mold.  It is specially created and designed to help the finished cast silicone mask fit properly.  The core is usually fiberglass and epoxy/resin.

    The pressure is not applied to the clay, but to the mold core and shell.

    The rest of the course series should help clarify the core's role in casting.

  • I've finished all 3 courses now and I've decided to buy The Monster Maker's The Ed Head 2.0 core seen here: It looks like they don't have a very big opening for you to reach in and put bolts, washers, and wingnuts in because of the funnel hole seen in the photos here. 

    Will I have to cut the bottom out to reach the bolts, washers, and wingnuts added on the neck or bib like in these photos? What about the C-clamp as mentioned in the original post? When using this core, will I have to cut out the bottom to make room for the C-clamp?

    Also, what salmon colored clay was used on top of the core in this course seen in the original post? In the list of needed materials it says the only ones needed are EM210 white clay and the soft modeling clay from Reynolds which are both white. I know Chris stated that the color doesn't matter but I'd imagine using a white clay on a white mold would make it harder to see what clay residue is still on there when cleaning the mold as seen in the part 2 course.


  • Chris EllerbyChris Ellerby Los Angeles Admin
    The clays listed were for the mold-making process, since this lesson did not focus on creating the sculpture its self.  For the primary sculpt clay you could use something like Chavant NSP or Monster Makers clay.  Both are good options.

    The Ed Head is a fantastic sculpting armature, but it is not really designed to work as a mold core for silicone masks.  You might be able to modify it to get it to work as a core, but you would be on your own there since that is not a standard practice.  It would likely involve cutting away sections in the base as you mentioned and possibly finding a way to add a fiberglass flange around its base so it can socket into the outer mold.

    Has anyone here modified an Ed Head to use it as a core?

  • Brian LeBrian Le
    edited October 2021
    What if modifying the Ed Head doesn't work out? What core can I use? Any near Orange County or LA? Using the search engine I cant really find any other kinds of cores period except when I found a core from Immortal Masks it said they're back ordered a month or 2 or something that long. All I could find was the backordered core and the Ed Head.

    "It would likely involve cutting away sections in the base as you mentioned and possibly finding a way to add a fiberglass flange around its base so it can socket into the outer mold."

    Could the red circles seen here on the Ed Head be used as a flange? Will the flange under pressure? Does the flange need to be fiberglass or can it be made of other materials? I was thinking wood and maybe some sort of putty. What is the purpose of socketing the outer mold? If I modify the Ed Head could I risk failing to make the mold?

    "This lesson did not focus on creating the sculpture its self."  

    I've taken Human Head Anatomy & Sculpture course because that's the closest one I can find where I can make a human face like the one in the Silicon Mask Making course. Is there any others I should take when trying to make realistic silicon human masks?

    Post edited by Brian Le on
  • Chris EllerbyChris Ellerby Los Angeles Admin
    Hi Brian,

    Cores for silicone masks are normally purpose-built by the artist and not an off-the-shelf product.  Just as you design your mold based on your sculpture, the sculpture and the mold are both designed based on your core.

    In the first image you have a red circle on, the flange is the flat lip that goes around the base of the core.  That sockets into your outer mold, centering and holding the core in place.  The Ed Head has no flange, so you would have to add one.  The flange needs to be very solid so it can support the weight of the core and keep everything perfectly aligned.

    The core is very specifically designed so the outer mold, once it's created, will lock into it and support it.   It is also designed so the masks created on it will fit snugly and blend into the eyes/mouth properly.

    A big challenge here is that normally a very specific set of steps (as outlined in the video) is taken to create a silicone mask, and once you fully understand that process you are freed up to make changes or do things differently.  If you are first starting out and making big changes to the process, like not making a standard core, the chances of having successful results start to drop quickly.

    I created the image below to help illustrate how a generic silicone mask mold could be designed.  You can see how the core sockets into the outer mold, keeping it perfectly centered to allow even space between the core and the outer mold, which is where the silicone will be added.  And everything is bolted together to hold things securely in place.

    Hope that helps!

  • Chris..i am looking at that image...and wondering..what is the "usual" rule for the thickness of clay between the core and the mothermold? In the taxidermy business we do matrix molds with about an inch between the two but the details of the foam impression made in them is on the INSIDE of the poured urethane rubber which is poured like this..the urethane rubber is a "sleeve" inside the fiberglass shell....

    I do know fiberglass directly on the sculpt itself is how the impression is made for the mask but the density dimension between the core and the fiberglass is what i am wondering...that way there is not a thicker mass of silicone in one area and not even all the way around..if this makes sense?

  • Chris EllerbyChris Ellerby Los Angeles Admin
    The thickness of the silicone depends on your character's design.  Some areas may need to be thicker if they have large sculpted details, others may be thinner to help with flexibility. 

    The illustration above is simplified to help visualize the process, but the void where the silicone is would be where you have added clay to the core for your character sculpture.   What is clay in the initial sculpture becomes silicone in the casting process.

    So if your character had a heavy brow, protruding cheekbones, a large chin, etc. those areas could be quite thick, but areas like the blending edge around the eyes could be quite thin.

  • "Cores for silicone masks are normally purpose-built by the artist and not an off-the-shelf product."

    Do you know any courses or guides on here or elsewhere about cores and making them? I cant find much information on them when looking them up. Also, how long does it normally take someone to make a core?
  • Chris EllerbyChris Ellerby Los Angeles Admin
    Hi Brian,

    I was able to find one location in the UK that sells an armature/core for silicone mask making.

    The price looks reasonable, considering the expense of making your own.  With a bit more searching you may be able to find others.

    We don't have a course on silicone mask cores at the moment.  The silicone mask-making course does cover a lot of information about the core, so with a bit of research, you should be able to make your own from a lifecast.  I don't know of any resources that cover the full design and construction of a silicone mask core.  But with a bit of google/youtube research, and possibly watching this course again, you should be able to design and build your own.

    The basic process (as I might approach it) is as follows:
    • Make a silicone or alginate life cast from the shoulders up, with a plaster bandage shell.
    • Pour melted clay into the mold to create a positive bust
    • Simplify/remove the ears, leaving a small mound where the ears were to provide some space for the wearer's ears.
    • Smooth out and simplify the surface, and remove clay in areas where you want the fit to be snugger.
    • Simplify the area around the eyes so your final mask can blend properly
    • Sculpt the mouth in a slightly open position with a small shallow cavity between the lips
    • Sculpt in some keys and a flange so the core could socket into and be centered/supported by the final outer mold
    • Mold and cast in epoxy and fiberglass. 
    That's just a quick outline to cover the basics.

    Hope that helps!

Sign In or Register to comment.