Ear Casting

For our first full lesson back for creature design, we had to create a cast of an ear. The ear, once it is cast will then is used to create a prosthetic for our creatures we will be designing. Before we can make the positive of the ear out of plaster, we first had to use alginate to make a negative of the ear. To make the negative of the ear we had to plug the ear using cotton wool, the pour the alginate in to the ear using the top of a paper cup to hold the mould of the alginate ear.  Once the alginate is set you can then make a positive of the ear out of plaster. After the plaster is set the ear is then ready to be sculpted on to, so that a desired effect can be created. The process of this a cast can be used in the film and television industry, to make a bespoke prosthetic for an actor.  Below are some pictures of the ear cast being made and the method.

 

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Products/Tools needed

  • Cotton wool
  • Paper cups x2
  • Vaseline
  • Clingfilm
  • Bowl
  • Water
  • Alginate
  • Mixer
  • Modrock
  • Clay
  • Plaster

 

Method

Making the alginate negative

  1. Lie model down on one side a flat surface
  2. Put ear through cling film
  3. Vaseline the edges of the cling film down
  4. Put cotton wool in the ear, to block the alginate from going in the ear
  5. Make a wall around the ear with the large end of a paper cup
  6. Put tepped/room temperature water into a large bowl, (As alginate only has a short working time, around 3 minutes, you have to work fast when using it.)
  7. Pour the alginate into the bowl of water (this is probably a two man job,  so get a friend to pour the alginate while you mix) and mix together with an electric mixer, until it’s at a watery porridge consistency, this is when it is ready and you will have to be fast pouring it in to the ear.
  8. Pour alginate into ear, start by pouring behind the ear, until the ear is full submerged by the alginate. Make sure to put paper towels around the bottom of the cup to stop any leakage.
  9. Put a finger in the ear and move it around to remove any bubbles in the alginate
  10.  Leave the alginate for about 5 minutes, until the alginate goes solid.
  11. Remove the paper towel, the cup from the ear. ( to remove, pull the cup gently push it towards the back of the head, and then wiggle upwards to remove).

Making the plaster positive

  1. Cut another paper cup in half and place on top of the other cup.
  2. Use a couple of pieces of Modrock to hold the two cups together, and use clay to re-enforce the join of the cups and to stop the plaster from leaking out.
  3. Mix up plaster
  4. Pour the plaster into the new mould with the alginate ear in. Pour the plaster to the side of the ear  and move around to get the plaster into the ear, remove any air bubbles by gently shaking the mould, then continue to pour plaster into the mould, to give it a good base.
  5. Once the plaster is set, remove the clay and modrock from the outside of the cup and then cut away the remaining of the cups.  Once the cups have been removed, gently pull away the alginate, which will then reveal the plaster casting of an ear.

 

Thanks for reading

Hannah xoxo

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