So, last year I got a few of these skully beauties at Walgreens, (also at BigLots, but more expensive) and used them to make my zombies. As we all know, even cheap skulls add up in cost fast. At $10 a pop, I could only budget for a couple. And as you all also know, that just cause I could find these last year, doesn't mean I'll find them this year, or ever again for that matter. Below be the skull.



So, ever since I've wanted to attempt to make a mold of one. I've made rubber molds a bunch of times before, but on a really small scale. (war minis) So I researched, and I basically followed the methods from these two tutorials, especially because I wanted to use Smooth-on's Dragon Skin, as I still had some laying around.

Smooth-on Tutorial

After brushing on about 4 layers of Dragon Skin onto the skull, I applied some Smooth Om Shell Shock to create a support mold. That was the hard part, I'd not do it again. I can see that stuff having a ton of uses, but not for making molds! It starts out thin like paint (and running off the mold everywhere) only to quickly thicken and turn tacky like chewing gum lol And in the process, I broke one of the halves and had to glue it back together. lol

Anyhow, after it was all done, in went a small cup ( about 4 ounces) of Smooth-On Foam it 3, a two part liquid expanding foam. That stuff is epic! Twenty minutes later, I had a very light weight replica!!

So, I spent about $30 for the Dragon Skin, and about that for the Shell Shock, (which I still have most of) and about $25 for the Foam-it 3. So the up front cost of this is kinda high, but I bet I can get at least 12-15 skulls out of a trial size of Foam-it. That's like $1.60 a skull. How ever, when that runs out, I can get more Foam-it by bulk, a LOT cheaper per weight than the trial sizes. I can cast these for next to nothing.

As you can see in the pics below, this stuff can be carved pretty well. I cut the jaw away from one skull, and can re-articulate it. These casts are going to be an excellent base for the ground-breakers I want to start on next.

Here is the original next to a cast.




Here is the one I carved the jaw out.




The mold and outer shell. I will add that this sucks as an outer shell, and I will be making a new one. One that is square, or at least flat on the top so it will sit up side down, will work much better.




And one painted. Kind of a rush job. Spray painted white, the washed with thinned wood stain. forgot the wood stain was thinned as it was trying to left the spray paint, as I was too impatient to let it dry completely, lol! and it still looks like I just dug it up. lol




Here is the mold in a box, it is just open on the bottom, no cuts or seams. Here I got some pics of the casting process, a little foam goes quite a ways. Poured into mold, and tilted it around so that it coats all the inside surface before I set it in the box to keep it upright and somewhat level. I have to do this all very quickly, I have about 1 minute to do this before it expands to the point it won't flow around the inside of the mold anymore. I sit the board on top to help create back-pressure for the expanding foam, the hole to let excess escape.


cast skull01


After about twenty minutes, I pop it out. take off the support mold, then starting at the back of the skull, turn it inside out over the front, then carefully pull out the mold from the eyes and nose. Last image is the cast with the inside out mold. Weird thing is, once out of the mold, the casting crackles like Rice Krispies cereal for about the next ten minutes. lol


demold skull01


I will also update since the time of this writing, after around 20 pulls from this mold, the foam started sticking to it, and peeling away the outer layer of foam leaving it in the mold. I had a time having to clean it each time it was used. I had not been using the correct kind (if any) mold release. After getting the right kind of release agent for foam from smooth-on, results improved.  Depending on the usage, I now pour a small amount of smooth-on 300 resin in the mold first and coat the inside with that. It sets in about 3 minutes, then I pour the foam in as usual.  The produces a foam filled skull with a rigid, durable plastic surface.