Tuesday, 12 April 2011

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.


101 comments:

  1. Bravo! I was fascinated with the character, the personality of the drawing, with the finish that give the materials and colors you used, and the precision with which you work.
    Congratulations. I invite you to meet my channel on youtube, where I uploaded some videos of my tests and a tutorial I did on principles of animation: http://www.youtube.com/user/Labudinera

    ReplyDelete
  2. Hi Nathan, I'm so glad I have recently discovered this blog (and your brothers) they have been a big help. The only thing Im still not that clear on is once you have the polyurethane copy of the mouth, do you sculpt the lips for each expression and then make another silicone mould? so you effectively end up with 11 moulds, one master and 10 expressions?
    Thanks

    ReplyDelete
  3. Andrew - Glad you find my blog useful :)
    Ideally I would have liked to remould the mouths after sculpting lips and cast polyurethane copies, but we chose not to. It was just a matter of time and cost.
    After sculpting facial expressions onto th faces we justed painted over the baked clay and plastic and used them on our puppets. You can see more in this post-

    http://nathan-flynn.blogspot.com/2011/04/replacement-puppet-faces.html

    we have 1 mould, 1 master and 10 unique expressions :)
    Hope this answers your question.

    ReplyDelete
    Replies
    1. Thanks Nathan- that helps a lot. I have a much clearer idea of how to tackle my own puppet now ^_^

      Delete
  4. and why did you put the frame in hand made ​​firm

    ReplyDelete
    Replies
    1. Hi Flo
      Im sorry but I don't think I understand your question.

      Delete
  5. how did you color the eyes mold

    ReplyDelete
  6. why did you put the clay to make the hand and foot

    ReplyDelete
    Replies
    1. Flo
      The polyurethane resin I used to cast the eyes is naturaly an ivory colour. The pupils were painted on later.
      _

      Do you mean the terracotta clay?
      Half submerging a sculpture in clay is a necesarry part of making a 2 part mold.

      Delete
  7. Hey Nathan,

    I was just wondering what brand of silicone did you use for your moulds?

    ReplyDelete
    Replies
    1. Hi Lee,

      For mould making I use T28 Silicone Rubber from Tiranti.co.uk
      Here's a link -
      http://www.tiranti.co.uk/subdivision_product_list.asp?Content=Silicone+Rubber&Subcategory=51&Subdivision=

      Delete
    2. Thanks! helps a lot and is much cheaper than most brands I found.

      Delete
  8. hello nathan
    What is that you used as catalyst

    ReplyDelete
    Replies
    1. FLO-
      The catalyst is a chemical that triggers the silicone to turn from liquid to solid.
      Silicone often comes supplied with the correct catalist.
      :)

      Delete
  9. ok this is a small bottle but how should he put gout

    ReplyDelete
    Replies
    1. I think this question didn't translate correctly, but I'll try to answer.

      The silicone should come with mixing instructions that tell you the mixing ratio for the catalyst.
      The silicone I use has a ratio of 20:1 (5%).
      To use a digital weighing scales to weigh the silicone and catalyst so I know I've poured the correct amounts.

      I hope this helps.

      Delete
  10. hello
    When I mix the part A with part B in the mold
    you will like it hard or soft latex

    ReplyDelete
    Replies
    1. Hi FLO,

      Sorry I don't understand your question.
      Could you give me some more information?

      If your refering to the polyurathane resin, mixing part A and B will creat a hard, solid plastic.

      Delete
  11. hello
    and What should I take as to the latex arm and hand

    ReplyDelete
    Replies
    1. Hi Flo,

      I'm having a bit of trouble understanding your questions.
      Are you asking about casting puppet parts in latex?

      If your casting latex arms and hands you will need a 2 part mold made from something rigid like plaster or resin.

      Delete
  12. How do I put liquid into the mold to make the arms, leg, hand
    I'm sorry you do not understand me

    ReplyDelete
    Replies
    1. Hi FLO,

      Ah, I understand you now :)
      The liquid silicone is simply poured into each half of the mold. Then I insert the armature and quickly joint the two mold halves together.

      This post shows some images of the process-

      http://nathan-flynn.blogspot.co.uk/2011/02/hands-part-3.html

      Sometimes I paint in the first layer of silicone to avoid getting air bubbles on the surface. After the mold is joined and clamped together, some excess silicome will squeeze out the sides. This can be cut off later after the silicone has cured.

      I hope that helps :)

      Delete
  13. ok thank you for the link but what is the name of the silicone

    ReplyDelete
    Replies
    1. I can Highly recommend this Silicone Kit from AnimationToolKit.co.uk
      Its called Silicone Skin and comes with everything you need.
      AnimationToolKit.co.uk Silicone Skin

      Delete
  14. thank you very much for your help
    you have really helped me

    ReplyDelete
  15. excuse me I have one last question how do I mix catalyst with silicone skin

    ReplyDelete
  16. hello nathan
    how many drops of catalyst should I mix with the silicone skin

    ReplyDelete
    Replies
    1. Silicone Skin needs 5% catalyst.
      The silicone to catalyst ratio is 20:1
      For example, if you had 100g of silicone you would need to add 5g of catalyst.
      :)

      Delete
  17. ok ok ok
    thank you very much
    :)

    ReplyDelete
  18. Hi Nathan, how did you end up placing the magnet system?

    ReplyDelete
    Replies
    1. Hi Ben,
      I believe this post should answer your question-

      http://nathan-flynn.blogspot.co.uk/2011/04/replacement-puppet-faces.html

      :)

      Delete
    2. Oh thank you! You and your brothers posts have helped me so much!

      Delete
  19. hello nathan
    I called Tiranti for T28 Silicone Rubber + T6 Catalyst 1.05kg kit but he did not respond or could I find then that product

    ReplyDelete
    Replies
    1. Hi FLO,

      Tiranti might not be able to ship outside of the UK.
      The catalyst is considered a Hazardous item.

      Are you located in France?
      You might have to search some local websites.
      Don't search for 'T28' because that's just a name that Tiranti uses. Instead I suggest you search 'mold making silicone' or 'molding silicone'.

      I hope that helps :)

      Delete
  20. yes I am French but I found thank you

    ReplyDelete
  21. this product it is well
    http://www.ventes-internet.com/index2.php?track=g&url_principal=peche/leurres-souples/silicone/chrissvi_RTVBLANC.php

    ReplyDelete
    Replies
    1. That looks great FLO.
      Im glad you found some :)

      Delete
  22. hello nathan I would like to make real hair with hair goat
    it's good or not

    ReplyDelete
    Replies
    1. Hi FLO,

      I've no experience using real hair on puppets before so i can't really offer any advice.

      Using goat hair can look great (for example 'Fantastic Mr Fox') But its very challenging to work with.

      Delete
  23. ok I'll put hair as in paranormal

    ReplyDelete
  24. Hi nathant
      I know you was not but hair specialist hair paranorman are made of goat hair product but what I can add hair to animate?

    ReplyDelete
    Replies
    1. Hi FLO,
      I wish I knew how they achieved the hair control in 'Paranorman' and 'Coraline' but I haven't got a clue.

      I would guess the hair is held together with lots of styling products (spray / wax) and has thin wire incorperated into it.

      Sorry I can't be more help.

      Delete
  25. I still have a question about hair how I can keep the hair on my head puppet

    ReplyDelete
    Replies
    1. I think hair can be individually punched into silicone or latex.
      I've never done it myself so i'm not sure how it works.
      Check out this video -
      http://www.youtube.com/watch?v=1y-UG-ZNTDM

      Could you maybe attempt to transplant hair from a toy doll? (Barbie)

      Delete
  26. thank you very much for your help

    ReplyDelete
  27. it is normal that when I sink my two-part silicone to make the mold when he puts glue and silicone skin in the molds that I do think it sticks as you think it is normal or is it you that I moulles make my plaster: (

    ReplyDelete
    Replies
    1. Hi FLO,

      Let me just clarify.
      -You have a plaster mold.
      -You mixed the 'Silicone Skin' and poured it into the mold.
      -The silicone has now set but is stuck to the plaster?

      The silicone should pull away from the mold without tearing.
      If the silicone has fused with the surface of the paster then you have a problem. Did you use any release agent before casting?

      Delete
  28. I sink my silicone into a silicone mold but I do not agent release but what is

    ReplyDelete
    Replies
    1. I think I understand now.
      -You have a silicone mold.
      -You are pouring silicone into the mold to cast something?

      I don't think that will work. Silicone loves to stick to itself. If you're trying to cast silicone you will need to use a mold made of something hard like polyurethane or plaster.

      The general rule is-
      If you want to cast something hard, you use a soft mold.
      If you want to cast something soft, you use a hard mold.

      What is it you are trying to make?

      Delete
  29. I did wrong can be made ​​clear
    I was sunk my silicone into a silicone mold but I do not agent release but what is

    ReplyDelete
  30. I would make the body soft and hard head and face

    ReplyDelete
    Replies
    1. Ok, Thats great.
      So for the body you'll need a plaster/polyurethane mold to cast silicone body parts.

      And the for the head you will need a silicone mold to cast Polyurethane parts.

      Delete
  31. this is perfect thank you very much and when I will finish my film in one year I would put your name in the generic because you help me a lot

    ReplyDelete
  32. what do you guys do for eye lids?

    ReplyDelete
    Replies
    1. Hi aortiz.

      We use a few different methods for eye lids or 'Blinks' as we like to call them.

      For Roy the Mailman, we used plasticine to sculpt blinks. They're quick and easy to make but the drawback is, they remain soft and can easily get damaged.

      Elle the Actresses blinks are more complicated because she has lashes and make-up on.
      Her's are made from a thin shell of milliput that was cut a into shape and then painted. They're harder to make but they last longer.

      I hope that answers your question :)

      Delete
  33. hi nathant
    what is the plasticine do you use for sculpt hair ?

    ReplyDelete
    Replies
    1. Hi FLO,

      The hair is sculpted in Plastiline.
      'Plastiline' is very similar to 'Plasticine' but they have slightly different properties.

      I'm not sure what the name of the brand is but here's a link so you can see. -
      http://www.greatart.co.uk/Ceramics-Moulding-Sculpture/Other-techniques/Play-doughs/White-Plastiline-Air-Drying-Clay.html?utm_source=antidot&utm_campaign=02

      It comes in White or Grey and 5 different hardnesses. 40 = very soft. 70 = very hard.
      I'd recommend 55 or 60 (medium).

      Delete
  34. hi nathant the site that you gave dosen't ship in france have you other site please :)

    ReplyDelete
    Replies
    1. Hi FLO,

      I'm having trouble finding french websites here in the UK.
      Try doing a google search for 'plastiline' or maybe you can use another brand like 'Chavant NSP'.

      Delete
  35. Thank you Nathan I found

    ReplyDelete
  36. Hi Nathan!

    How did you get that matte finish on the resine casting?
    Have you sanded the piece or it just came out like that?
    My resine casting comes out glossy and I don´t get how to avoid that.

    Thank you for sharing all this valuable information!
    Congrats!
    Luciana.

    ReplyDelete
    Replies
    1. Hi Luciana,

      Thanks for the compliment.

      I didn't plan on getting the matte finish, it just kinda happened. The surafce of the casting wasn't an issue for me as they were primed and painted later on.

      It could just be the type of resin you're using. I find that Polyurethane resin usualy gives a matte surface, whereas Polyester is often glossy.

      Did your sculpted master have a very smooth surface? That also could cause the glossiness.

      If you're not going to paint your cast and you need it to have a matte surface, you could try spraying it with a clear matte spray. (Testors Dullcote)or gentely sanding as you suggested.

      I hope that helps :)

      Delete
    2. Thank you very much for answering!
      It helps me a lot!

      Luciana.

      Delete
  37. This comment has been removed by the author.

    ReplyDelete
  38. Hey Nathan, thank you for creating this wonderful blog. You and your brother both do excellent work, the quality is really impressive. I have one question though, what brand/make of polyurethane or fast cast resin do you use?

    ReplyDelete
  39. So after reading through the comments on some of the other posts, I realized you already kind of touched on my previous question. Since I'm in the US, it seems like smooth-on is my best bet for supplies. In terms of moulding/casting the head, do you think Smooth-On's Oomoo would work for the mould, and that the Smooth-Cast 305 would work for the casting? Also, I think I am going to go with the Shore 10A Dragon Skin for casting the body, but what resin would you recommend using to mould the body? Thanks again, your blog has been extremely helpful. Cheers.

    ReplyDelete
  40. Sorry, one last question. Do you use oven baker or air dry terracotta when making the moulds for the body parts?

    ReplyDelete
    Replies
    1. Hi,

      First of all, thanks for the compliments.

      I'm glad my blog has been helpful. :)

      Oomoo, Smooth-cast 350 and Dragon skin sound like good choices to me.

      For the body mould you're going to want to use a polyurethane resin. I used the same stuff that I cast the puppets head with. If you’ve got enough smooth-cast 350 then that will work.

      (remember to build up the mould in layers rather than all at once. Polyurethane heats up when it's curing and you don't want it to melt your sculpt.)

      The Terracotta clay I buy is intended to be fired in a kiln but thats irrelevant. You'll want to keep the clay wet for the whole moulding process. If it dries then it will shrink, crack and ruin the mould.

      I hope that answers your questions.
      Good luck with your project.

      Delete
  41. Thanks for the advice and the quick reply!

    ReplyDelete
  42. Hello Nathan
    I love the animation film since 9 years and now I would like to do an internship to the aardman studio.
    Do you know somebody who can me take to do an internship
    Thank you
    Cordialy
    Florian

    ReplyDelete
  43. This comment has been removed by the author.

    ReplyDelete
  44. Excuse me i made a mistake
    I'll let you know

    ReplyDelete
  45. I Nathan
    I sent you an email :)

    ReplyDelete
  46. hello
    i sent you an email yet :D

    ReplyDelete
  47. Thanks Nathan for your message I hope it will work

    ReplyDelete
  48. hello Nathan
    During the summer holiday I would like watching your film "opening night" but on this web site there is just the behind the scene where may I see this movie?
    Thanks :)

    ReplyDelete
    Replies
    1. FLO

      Our Film 'Opening Night' isn't finished yet.
      We had to take a break from working on it.
      I'll be updating the blog with more progress soon.

      Delete
  49. Hi
    Oh ok me too i have to take a break because of financier level
    Thanks
    bye :)

    ReplyDelete
  50. Dear Nathan ,

    you have a great blog that really have help every one who are interested in making a stop motion movie .
    i have a question , where i can get the smooth cast 30 that you used to cast the body ( link ) and it will be great if you have a store name and address that is located in London for all the supplies i can get supper sclupy , rubber silicon and the rest because shipping to Egypt is to expensive and may be i could make a friend buy them for me.

    one last request what about shooting some learning videos it will really help .

    thanks

    ReplyDelete
    Replies
    1. Hi Haytham,

      Glad you like my blog :)
      I don't buy Smooth-on products because you're expensive and harder to get here in the UK.
      Smooth-Cast is a brand name for Polyurethane resin. (also know as 'fast cast' resin.)

      Here are some website links-

      http://www.animationtoolkit.co.uk/
      They sell loads of stop motion model making materials including, resins, silicones, armatures etc.

      http://www.tiranti.co.uk/index.php
      Great for silicones, resins, tools and clays (sculpey)

      Both stores are located in the UK.
      If you try searching for Polyurethane resin online, you might find a supplier closer to you.

      I hope that helps.
      All the best
      Nathan.

      Delete
  51. Hi Nathan,
    Thanks for your reply

    i need you to clarify something about the foot and hand casting , do we use silicon or latex foam and which is better in the way of using and also for the final result ? one last thing is rubber silicon that we use for molding is different from the one we use for casting

    thank you

    please could you shoot a video for the whole puppet process it really will make us happy plzzzzzzzzzzzzz.

    ReplyDelete
    Replies
    1. Hi Haytham,

      You can use silicone or latex to make puppets, but silicone gives better results, especially for hands and feet.
      In my opinion silicone is easier to use and will last longer.

      Yes the silicones used for molding & casting will be different.
      Silicone for molding is commonly found online.
      The silicone needed to cast puppets is a specialist item because it's softer and more elastic.

      Maybe one day I'll film some puppet making videos. But no promises. :)

      Delete
    2. Thank you for you reply . could you please post a link or the name for a similar silicon brand in USA.

      by the way what is the best size for the puppet we use for stop motion


      thanks

      Delete
    3. You could try Dragon Skin 10 from Smooth-On.
      I haven't ever used it myself but I hear it pretty good.
      ( I'd pick the medium speed catalyst)
      http://www.smooth-on.com/Silicone-Rubber-an/c2_1115_1129/index.html

      My puppets are around 12 inchs tall.
      The height of your puppets will be dictated my the amount
      of space you have for sets and the design of your characters.
      I hope that helps.

      Delete
  52. hello Nathan
    It's good or not to make :body. hand. foot. etc with this

    http://www.tiranti.co.uk/EdgeImpactShop/product.php?Product=1259&Content=T20+Silicone+Rubber+%2B+T6+Catalyst+1.05kg+kit+Mouldmaking+Silicone+Rubber+T20+Silicone+Rubber+

    and what is the Polyurethane resine do you use ?
    Thank you
    Florian

    ReplyDelete
    Replies
    1. Hi FLO,

      Yes that Silicone will work.
      Tiranti also sell Polyurethane resin here -
      http://www.tiranti.co.uk/EdgeImpactShop/subcatdivision.php?Division=228&Content=Biresin+G26+Urethane+Resin+

      Delete
  53. Hi
    What is the silicone do you use for the skin ,foot etc
    thank you
    Flo :)

    ReplyDelete
    Replies
    1. because on the web site they said that it's just for mold
      I doont understand !! :)

      Delete
    2. Hi FLO,

      Yes on the website it says it's for mold making,
      But I used it for puppets with no issues.

      Delete
  54. ha ok thank you nathan !! :)

    ReplyDelete
  55. hey ! Nathant
    when you are ready to make your mold did you put some glue spray on the puppet's face ?

    ReplyDelete
    Replies
    1. Hi FLO,
      I hope i'm understanding your question correctly.
      I didn't apply any glues or sprays to the sculpey faces before pouring the silicone mold.

      Delete
  56. yes you are understand my question ok thank you :)

    ReplyDelete
  57. Hi Nathan,

    I'm a huge fan of your blog, and of Josh's blog too. I must have read all the posts about a hundred times now. Thank you for sharing such amazing information. I'd second calls for online lesson videos or a book - I'd buy either the day they came out! Anyway, I am slavishly trying to follow the process for the replaceable faces, and have a couple of questions, as I see you are still around to answer questions, despite how busy you must be!

    1) by molding and casting the master head, you are using a resin cast of the K&S tubing, instead of the actual thing. Is that right? I assume that still works OK for attaching the hair? If you were attaching the hair permanently, rather than having it detachable, would you bother with the square tubing? I can't think of another reason for it.
    2) I have been having trouble using polyurethane resin for casting. I tried to create an eye-holder as you have used here, but the square tubing ended up completely embedded and unable to be removed. Is that why you used plaster? Instead of trying again, I was going to make one of out sculpey ultralight and bake it. Do you think that would achieve the same results?
    3) the milliput cap, for the neck to go in. Does the neck just push in and stay there? Or do you need to glue it/attach it some other way?

    I'm sorry for the length of the post, and really appreciate this great resource you've created. I see you and your brother have been making great strides with other projects since this one, so it's really generous of you to spare the time to help us amateurs!

    ReplyDelete
    Replies
    1. argh! rereading Josh's answer to the question I put on his blog, I see the K&S is there for the neck to go in as well! That makes so much sense. So when you make the clay neck shape, you put a thin even layer of milliput over it, then push the K&S through it, into the clay? Then when you remove it later, the K&S is inside the neck spout, so the neck can fit inside?

      I'm slow on the uptake, but I think this has answered my questions 1 and 3. Sorry!

      Delete
    2. Howdy Dave,
      Thank you for the nice comments and apologies for the slow reply.

      regarding question 2, yeah I guess you could use something like sculpey to make the eye socket mould. I used plaster because it's the cheapest option.
      It's possible that your fast cast idea will work too. Adding a little bit of release ajent like vasaline will stop the resin from sticking to the K&S.

      I hope that helps and good luck with your project. ;)

      Delete
  58. Excellent blog. If you are looking for steel fibre for precast then contact only at Precision Drawell.

    ReplyDelete