To starting making the Krogan head I needed to make a base/foot om my face cast, and since I knew that the weight of sculpting and mold making could reach up to 50 kg, I added some wheels om my sculpting table so turning my work would be easier. I had to make my face cast steady so I made a plaster wall on the bottom part (as shown in the picture to the right), and I sprayed the plaster and wood board with clear lack for sealing it to not soak up the water from my water clay.
I was now ready to start my sculpting. I used 50 kg water clay and sculpted it in 3 days, during which I took over 50 pictures compiled in a short video (see the sculpting video in the menu).
I sculpted with blanks of the eyeballs in it (shown further down). I followed reference pictures, to help get an overview while blocking out the big shape of the head, and to keep track of where my (the model) mouth and eyes are I used some wood sticks (shown in the pictures in the video). After finishing up the sculpting, I sealed the clay with clear spray paint (shown in the 3 pictures below).
Silicone and fiberglass outershell
All silicone and fiberglass processes for this project are done the same way, I will describe all of it here and refer to this paragraph when I'm explaining other parts of the build further down in this tutorial.
First I had to make dividing walls with keys (made in clay, look at first pictures on the right).
I used an addition cured silicone with 22 hardness for the mold making. The mixing ratio is one to one by weight. I covered my mold, starting with the face, so the silicone layer was roughly 1-1,5 cm thick. I then added silicone keys which were made from pre-cured silicone cubes (see reference photo). The edges were then trimmed and I had to make another dividing wall on the middle of the face to get a total of 4 part fiberglass jacket.
Fiberglass jacket is made by first mixing a polyester layer with 2% hardener and Cab-O-Sil filler which is then brushed on the surface of where the mold is going to be. Wait until it is tacky and then add fiberglass chopping on and it is ready to dry. When dry add polyester, 2% hardener and cover the whole surface again and might put more fiberglass chopping mixed with polyester and hardener around the silicone-keys and places the fiberglass-tissue have problems of getting contact. This it to minimize delamination (air-pockets in the fiberglass). Then proceed to mix polyester and hardener to wet the fiberglass tissue and cover the mold, 2 layers of fiberglass tissue and 1 layer of fine tissue (for the beauty coat) to get a clean surface and not sharp and pointy mold in the end. (you'll find a timelaps of this further down.)
When the front of the face was finished, I did the same on the back of the head.
All fiberglass needed to be trimmed with a Dremmel tool, and drill key holes before opening it.
After opening it, then it was time to clean away all clay and the jacket was done.
To make the skin that will be the thickness of the foamlatex, I laid water clay in the thickness I wanted for the foam. Them I made a new fiberglass mold of that. First with the mold open, then I closed the mold and sealed it together.
When this was done I had a core for my mold.
I had to fill all gaps with fiberglass filler to make the core as smooth as possible so the foamlatex wouldn't stuck or rip.
I had to make a master-mold of the core so I can remake it for as a "helmet" for the foam-latex skin. I made a little video of the process of making the master-mold and core. with the same procedure as above, silicone and fiberglass. (see the fiberglass and core video)
Skin and hacks
When i closed my mold the first time I noticed that it was impossible to push the silicone keys in their spot in the fiberglass jacket. To solve this problem I made a hack that would help me pull the keys in the right spot from the outside. By carving an opening where the keys are in the jacket mold and sew two strong threads through the silicone keys I could now pull them to the right spot from the outside.
For making the skin I had to inject foamlatex with a big syringe, and I had to just guess the amount of foam I would need. I did the filling twice and here is why;
My first round of foam I used 3 big batches of foamlatex with some brown and black pigments in the hopes of getting god dark brown base color in the foam.
- One big batch of foamlatex contains
375g latex base
80g foaming agent
38g curing agent
15g of gelling agent
Mixing at speed 1 for 1:00
Foaming at speed 12 for 6:00
Refining at speed 4 for 2:00
Ultra refining at speed 1 for 3:00
gettling addition at speed 1 for 0:30
Three rounds of this batch would have filled the mold, but I had a problem with the syringe which were leaking more than I thought. Also I need to add more bleeders (see description of what bleeders are in the paragraph below) so the foam would fill up in the more tricky places like the chine or the eyelids, see picture on the right. I also did not like the base color of the first batches, it turned out gray.
The video on the right show a time laps of the filling of the mold with the gray batch of foam-latex with the help from another student and our teacher.
Bleeders are small funnels that will indicate when the mold is filled in several sports by leaking "bleeding" out the foam. They also help steam from the foam-latex to escape.
If foam-latex get too wet it can have steam leaks, it will deform the result and lose the softness of foam. As you can see in the pictures there are quite a lot of small tubes in the inside of the mold, that's the bleeders and you can see the injection tube. Also note that I have blocked out the mouth with a blue silicone piece and clay.
To fix the chin I ended up drilling a lot of hoes for the air to escape. And for the problem with the eyelids I made bleeders on the outer jacket by connecting a hypodermic needle through the silicone and fiberglass mold.
After I fixed everything that needed to be fixed I run another round of 3 latex batches, but this time I wanted a red brown color to match the color of flesh. It turned out as a fabulous pink instead as flesh toned, but the cast was whole and the foam perfectly baked, so this is a piece I can work on.
Here is a little time laps of how to open the mold where you can clearly see how the mold was put together. (see the filling opening pink foam video)
I decided to make the inner helmet of my fiberglass core out of worbla. This is to that the huge fiberglass skull would sit securely to the model. TO make the pattern for the inner helmet I used aluminium foil and tape).
To make the worbla helmet comfortable to wear I started making the base out of a layer of 2 mm craft foam, I didn't want worbla seams to touch my head so i glued the foam pieces together first.
Then I added worbla and some metal plates to distribute the pressure of the fiberglass helmet.
I had to carve away the unnecessary bits of fiberglass to fit the shape I needed to be able to move my own head. To attach the worbla helmet to the fiberglass core I used bolts through the fiberglass and attached it with worbla on the worbla helmet. Worbla stick to itself perfectly so no necessary for sharp screws that might have been sharp or uncomfortable against my head.
The jaw was attached with bolts and in between my (the models) jaw and fiberglass jaw I connected it with more worbla so eventually when I open my mouth I also open Krogans mouth.
Then I made gums for the teeth. The gums are made with poly-morph that is kneaded together with acrylic paint to achieve the redness I needed.
The teeth were sculpted with paper clay which air dries and then was sealed with wood glue before paint. I painted with alcohol colors.
For a protective shield to keep them from get knocked out too quickly I sealed teeth and gum with transparent polyester-resin, that also made them glossy and look like spit.
Eyes and servos
I took a round object and casted a silicone bucket mold of it. I made a plastic F1 sample to find the center, made a foot to connect to with bleeding wholes, fixing point and keys.
I made a new bucket mold of that (this will be the finish mold for the transparent layer of the eye).
For making the the inner mold I had to sand away a layer of the dummy eye and sculpt the pupil back on it. This will help me getting both eye pieces with the pupil on the exact same place. Then I had to make a mold of this and that will be the eye-core mold.
I casted two eye cores for paint, painted them and then casted them in the bigger mold for transparent resin coat. This is the blue eyes you see in the photo-slider on the right.
I also casted two plastic eyes in the big mold for blanks in my sculpting, you can see the white eyeballs in the sculpting pictures on the beginning of this page.
Look through the first slider for pictures of this process.
The animation parts were very tricky to attach, but you just have to try until you make them fit in the right spot and then secure the pivot points. I had adjust the shape of the eye to make room for all joints. Eyelids are casted as a plastic ring that is shaped and fitted the eye and skull.
To create the eye movement animations I added a line of metal wire between eyes, eyelids and servos. On the left side, one servo for up and down movement and one servo for sideways view on the eye, and another servo to control the eyelids to close and open. The same was duplicated for the left side, using 6 servos in total for these movements.
I made eyebrow muscle animation too. Two servos where one control the inner eyebrow and one servo control the highest point of the eyebrow.
All servos will be controlled by either a controller for demo and then an arduino that will be programmed to do facial movements in a pre set sequence.
First I had to clean the foam to stop it from aging. This is done by sub merge it in a bucket of water and soap, then rinse it 10 times (until it don't bleed out yellow color).
Preparation before paint also include patching all holes with bondo and reinforce weakpints with fabric so it won't rip apart.
For the paint I started with the base color, pigments mixed with liquid latex to make a PAX. This will keep the paint from cracking.
Blending colors to mach a Krogan color palette, applied using a brush on technique. a lot of cotton heads, sponge and airbrush.
Then work myself to a finish product.
At last, it is just gluing the skin on where the servos moves and the mouth.