40–49cm Dolls GIGI - first-time-sculptor's Mature Mini girl!

Hello all! I've been lurking here for longer than I'd care to admit, but now I finally have something to share.

This semester I started taking Fab-Lab at my university, which covers plastics fabrication and moldmaking! I've toyed with the idea of sculpting my own doll for years, and I figured now was the right time to do it. I don't really have much experience with sculpting, but I've been collecting dollmaking tutorials for a long time, and was lucky enough to attend Mr. YG's head sculpting course at KBJD this past April.

Our first assignment was to make a two-part silicone mold, so I sculpted the head rather quickly (it's still rough around the edges in these photos, as you can see) and documented the moldmaking process with it.



In this photo, I've already cut off the back of the head to turn into the headcap. The head is lying flat and flush against the clay.
Instead of building a mold box, my instructor taught us that using PVC pipe cut to size is a lot easier and uses less silicone (in most cases).
I chose pipe that would leave about an inch of free space around the head, and cut it into two pieces that were each about 1.5x the height of the head. These were hot-glued together during the moldmaking process to ensure that both parts of the mold would be the proper height.
I laid down a thick base of clay and set the head into it. I also pressed alignment keys into the clay with the end of a pen.
My instructor's advice is that tapered/conical keys are the most effective in creating a tight seal, and the bigger the better. It's also easier on you later on if you set the keys in an asymmetrical pattern, so you don't get confused with alignment later on- you can see I've made a tight cluster of keys at the top of the head.

I was lucky enough to be the instructor's guinea pig for the silicone degassing and pressure casting demos (which I sadly didn't get photos of). We degassed the silicone in a vacuum chamber, poured it into the mold, and let it set up in a pressure pot at 80psi. The silicone is Smooth-On Mold Max 30, for reference.
Degassing AND pressurizing is a bit of overkill, but it led to a really lovely end product with absolutely no bubbles.



Once the silicone was cured, I flipped the PVC pipe structure over and cleaned out all the clay that the head had been resting on.
For the second part of the mold, I glued in bamboo skewers around the edge of the head to act as vents, and a funnel to use as a pour spout.
Incorporating the funnel into the mold is great because it keeps things a lot neater and allows you to overpour resin into the mold later on, which can help prevent accidents with bubbles and air pockets.
Remember to use mold release before pouring the second mold! Here I've just brushed on petroleum jelly.



The mold was put back into the pressure pot for the second round.
Unfortunately, either the petroleum jelly or the pressurizing process knocked over some of my skewers, so I've only got three working vents They've been sufficient, but it's a little embarrassing because now the two remaining skewers are trapped in the mold...!
The funnel was fine, I just removed it from the mold before I had the presence of mind to snap a photo.

You can also see that I didn't do a perfect job of gluing the seam between the two pieces of pipe- silicone leaked out, and the second mold piece isn't quite as thick as I'd hoped. It's fine otherwise, though.



And here are the mold pieces together! Funny-looking, but successful.
Since I made them so thick, they're firm enough to withstand the pressure pot on their own without needing the PVC pipes for support. That's not completely necessary, but makes things a little more convenient.



When the two mold pieces are locked together, the "pegs" in the eye sockets and neck socket are flush together, which makes it so that resin won't gather in those spots, and thus retain the holes.



Poured resin (clear, because the grad students were giving it away for free and this is just a junk cast). Spilled a little, oh well.



Hello, world! It's Gigi's alien clone!



There's still a bit of flash around the edges of the eyes, and an annoying black speck that got caught in the resin, but otherwise it turned out about as well as I could've hoped!

This was just a test run- I've refined the head more and will be making a better mold in the coming weeks- but I'm going to be sticking to this process. I hope it'll be of some use to anyone who's been considering casting a head of their own!

 

Gigi's body has come along quickly enough. As with the head, it's all Apoxie Sculpt- the torso pieces are molded around styrofoam cores, and the limbs are all sculpted around drinking straws to create smooth stringing channels. I bought a bag of assorted-size plastic beads to use as joints.



Here you can see the styrofoam inside the upper torso...



...and the lower torso.



Sculpting on the styrofoam was great because once I was done, I was able to dissolve it all away with some acetone!



Once again with the lower torso. It's just fun to watch.

I've spent the past few weeks sculpting and refining and sanding (and sanding, and sanding... it's tedious but I actually enjoy it) all of the parts, including the head, and this weekend I finally had it finished enough for a test stringing with some spare wire.



Hands and feet were still in progress, but I'm proud of how far she's come.



The head looks super huge here, but I promise it's all perspective distortion! I have to take these photos with my phone because it's such a hassle to bring my camera kit to the sculpting lab.



And one from behind. I personally love the slouch, but I can tell it'll be corrected once I get some proper elastic to string her with- the wire is terribly slack.

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That's all I have for now, but I'll be sure to post more soon. This week I'm going to start making the molds for the body, and hopefully remember to document that process as well.

 

Started on the molds today!

Headcap:



I'm trying out something my instructor suggested- if it works, I'll be able to cast the magnets directly into the head pieces, instead of having to glue them in. I'll write more about it if it's successful!
Unfortunately, while pouring the silicone for this mold, I knocked over the funnel :dead I think I managed to set it back in place... we'll see. It shouldn't be too bad.

And the thighs:



I'm being ambitious with this mold in an attempt to save time and silicone.
The pour spout forks into two so that I can (theoretically) cast both thighs at once, instead of having to make and use separate molds. I also added a vent on the other side of each ball joint after taking this photo.

You can see that there are skewers pushed through each thigh piece, and a bead in each knee socket. There are also drinking straws shoved in the interior of the thigh pieces, with the skewers running through those.
The skewers and drinking straws and beads are all glued together so that they function as one piece that can easily be slid out from the bottom of the thigh piece.
Right now, that inner piece fills the voids of the stringing channel and socket of the thigh. I anchored the inner pieces in the mold in such a way that, when both sides of the mold are finished and the thigh pieces are removed, the inner pieces can be fitted back into the mold in the void that the thigh pieces occupied.
The inner pieces will be positioned in such a way that when resin is cast in the mold, it will form around these inner pieces, and when the casts are removed from the mold, the inner pieces can be removed from the casts- thus preserving the stringing channels and sockets, and saving me a whole lot of work.

All in theory, of course! On Wednesday I'll be finishing these particular molds, and hopefully making some initial casts on Friday? We'll see how it all goes.

 

Thank you!

I believe it's Smooth-On Crystal Clear, it's definitely a polyurethane. Unfortunately, it's extremely difficult to cast clear resin without pressurizing- you'd have to be incredibly smooth and careful while mixing and pouring, and even then, there would still be opportunities for air pockets to form.
The only alternatives I know of would be heating the resin (some urethane eye makers use a heat gun to draw bubbles up and out of the resin) or vibration, i.e. steadily tapping the mold to dislodge air pockets and bubbles. The former is tricky because some silicones and resins react badly to heat, and the latter is also tricky because too much vibration can actually create new air pockets.

 

I'm glad it could be of use! I'm a visual learner too- I've read dozens of casting tutorials over the years, but it's so much harder to absorb information verbally than visually (and I'm sure I've demonstrated how crap I am at verbal descriptions, haha).
This course has been perfect since I get to watch all the demos, so I hope by documenting it all it can help others like us who need photos to go by!

I didn't have the feet prepared in time, but I did test her standing while she was strung with the wire, and she was fairly steady. The elastic I ordered should be in soon, and that'll help a lot..