Moulding & Casting - Head

In this Post I'll be continuing the process of creating the head for the Actress (Elle) Puppet. In my previous post I completed the master sculpt of the head and facial masks. I will now be moulding those parts and casting out plastic copies.
You can see Josh's post about Moulding and Casting the Mail Man's heads HERE. I will be using the same process.
A general rule for mould making is -
When casting hard objects, a soft mould is needed. When casting soft objects, a hard mould is needed.

As my head sculpt is hard and I will be casting copies in solid plastic, I will be moulding the heads in soft silicone.

Firstly I decided where the 'pour spout' will be located. The pour spout is the cone shaped hole in the mould where the resin will poured in later. I start by making a small cone of baked sculpey and gluing it the the sculpture using a glue gun. The hot glue holds onto the sculpt securely but can be removed easily later without damaging the head. In the picture above you can see the pour spout located under the head. The second function of the pour spout is to suspend the sculpture up off the surface.

Locating where to put the spout is very important. When it is cut off later it might leave a visible mark. Therefore its best to put it somewhere where there's no detail and it won't be seen. I've chosen to put it on the top of the head where it will be covered by hair.

Another important consideration is air bubbles. If the spout is incorrectly placed then air can get trapped in the mould causing voids in the castings. If the pour spout is positioned in the 'highest point' then air will be able to flow out of the mould without getting trapped.

I built a box around the sculpture made from foam board. The sides are glued together with hot glue to create a water tight seal. I left a gap of about 1cm around the head so that the silicone mould will have sturdy sides.

The silicone I'm using is white in colour and cures in 24 hours with 5% catalyst. When mixing the two parts together small air bubbles are introduced. These annoying bubbles can cause problems later and without a vacuum chamber they are difficult to get rid of. My solution is to paint a layer of silicone onto the sculpture and let that set. This helps to capture all the details and reduces bubbles on the surface. I then top up the mould box with silicone. I pour it in a thin stream into a corner of the box (not directly onto the sculpt).

Using this method means any bubbles that are in the mould won't touch the surface of the sculpture and therefore shouldn't cause any problems.

Once them silicone has set I removed it from the foam board box. Using a scalpel I now have to remove the master sculpt from the silicone. I cut along the back edge in a zig zag pattern and then bend the mould open to remove the sculpt. Cutting only the back edge reduces the amount of visible seam lines on the castings. The zig zag pattern will help the mould line up when it closes back up. 

To cast the head I used Polyurethane (Fast Cast) Resin. This is a two part resin that mixes together in equal parts and cures in 30 mins. No mould release is needed. The resin is most fluid and viscous in the first minuet of mixing so I had to work fast and get the resin mixed and poured into the mould as quickly as I could. (There was no time to take a picture). I gently shake, rotate and tap the mould to coax any bubbles out. After about 3 minuets the resin starts to thicken up.

Above is my first casting next to the master sculpture. I cut the pour spout off the top of the head and lightly sanded away the seam line. The fast cast copy of the head is much lighter than the original. Weight is always an issue for stop motion puppets in the fight against gravity. Another positive is that  fast cast is much stronger than the sculpey original meaning it is much less likely to break during filming.

Above you can see that the silicone eye socket and eyes fit snugly into place, just as they did in the original head. I repeated this method to mould and cast the brow and mouth masks. I've cast 10 copies of the mouth and 3 brows that I will use to make all the different facial expressions required for the film.

The masks fit into place neatly but I will be adding a magnet system to hold them in place.

In by next post I will be doing more mould making, only this time they will be hard Polyurethane moulds for casting flexible silicone body parts.



Puppet Head Sculpt - Actress Part 2

Today's post is part 2 of the puppet head construction for 'Elle'. This is the part I really enjoy as it mostly consists of sculpting. Sculpting is a hobby of mine and you can see some of my work on my website Sculpt-Double.co.uk.

Tools

Above is a picture of the tools I use for sculpting. Firstly on the left are some different clays. Super Sculpey Firm is a grey polymer clay that can be baked hard in an oven. I use this most often and it's great for capturing detail. Next is Milliput epoxy putty. It comes in two parts and cures hard in about 5 hours when mixed together. I use this because its really strong and good for strengthening and sticking together armatures. The ball of grey clay is Plastiline. It's a non drying clay very similar to plasticine.

I've collected a lot of different tools for sculpting, but pictured above are the only four tools I ever seem to use. On the left is a scalpel used for cutting and carving the clay. Next is a playing dart without it's flight ( my favourite and most used tool). The tapered point works great for sculpting in details. The red plastic tool I use for roughing out shapes and smoothing surfaces. Finally the last tool is a pin with a home made Milliput handle. This is used for really small, fine details.

I wouldn't recommend spending lots of money on expensive sculpting tools. Often found items and home-made tools do the job. To smooth out clay I often just use my thumb and fine brushes but it requires a lot of time and patience.

Sculpting the face

In the picture above you can see I have roughed out the face onto the Milliput masks. For this I used Sculpey Firm. I've added features like the ears and nose and marked where the mouth will be.

In this profile shot you can see the seem lines where the different parts of the face will separate. Below are the two mask pieces away from the head core.

Above are all the different head components so far. Rather than sculpting multiple replacement mouths from scratch, I will be moulding and casting out copies of one mouth and sculpting alterations onto the casts. This way the shape of the nose and cheeks will stay consistent and only the mouth shapes and jaw will change.

The 'master' face above has no lips sculpted so that they can be added to the casts later. I have added a set of upper teeth because whenever they are visible they should stay constant in a fixed position.

At this point the head and masks have been baked hard. Above you can see the rough sculpt for her hair. This is made from Plastiline and slots onto the head with K&S. The hair (once finished) will be moulded and cast in silicone.

Because part of the hair covers the upper half of the face, the brow mask is reshaped to follow the hair line. This allows it to be removed from the face more easily.

Finally here is the finished (master) head sculpt ready to be moulded. My next post will show the molding and casting process.

Puppet Head Sculpt - Actress

Today's post is dedicated to the process of making the head for the character 'Elle'. I feel this is the most important part of a stop motion puppet and the hardest to make. A characters face will be under the most scrutiny from the audience and manufacturing it to express a wide range of expressions requires a lot of problem solving.

Both Josh and I made the decision to make solid, plastic heads that will use a system of replaceable masks to allow us to change the characters expression. We were inspired by the stop mo film 'Coraline' which used a similar technique to make the title characters faces. Unlike 'Coraline' we will be sculpting each facial expressions by hand. (we can't afford fancy 3d printers)

I enjoy using the replacement animation technique as it speeds up the animation process. adjusting a plasticine face between shots can lead to the characters face going 'off model' and the clay tends to get dirty.

I will be using the same process as Josh used to create the Mail Man Puppets head. You can see his pictures on his blog here.http://joshua-flynn.blogspot.com/2011/03/puppet-head-sculpt-mail-man.html

Head Core.

I started by making a solid core for the rest of the head to be built around. Above you can see a Milliput cap that slots over the neck and into K&S. I will want the head to slide on and off the neck in order to change face expressions while filming. The K&S locates the head to the correct position.

Eyes and Eye Sockets

Earlier in this blog I explained how I moulded various sized eye balls to be cast out and used in this film.Link Below you can see some of the eyes I cast. At this point they still had the excess pour spouts attached. They will be cut off and smoothed away later.

To keep the eyes securely in place I have made silicone eye sockets. I was worried that the fast cast eyes would slide around or fall out of the fast cast head. The silicone socket grips the eyes and holds them in the head nicely. To make the socket, I sculpted the shape in plasticine with the eyes in place. I then poured a plaster mould trapping the eyes inside. When i flipped the mould and removed the plasticine it left the correct size negative space for the silicone to be cast.

Above is the silicone eyes sockets that will slot into the head core. The eyes still roll in the sockets and they are unlikely to slip during filming.

Sculpting the Head Core.

Next I started to sculpt the characters head around the Milliput head core. I'm using Sculpey firm. Usually I would need to keep the weight down by blocking out the head with balsa wood. As I will be casting this head in fast cast resin (Polyurethane), I don't have to worry about using heavy clay.

As you can see I have added a space for the eye socket to slot into. Also I have added a K&S rig point and gap at the back of the head for the hair to slot into. The hair will be a separate silicone component.

Above is the head with the eye socket. You can also see the circular space where the neck slots in.

The shape and finish of this is not too important as the facial details and overall shape of the head will be sculpted into the removable face masks.

After baking the head I roughly sculpted a thin layer of Milliput over the face. These act as a solid base for me to sculpt the face onto. The faces will be divided into two parts. Brows and Mouths.

I applied Vasaline between the two materials to top them from sticking. Once the Milliput was cured I removed them from the head.

That enough for now.

My next post will continue with the puppet head construction. More pictures soon.