EAR CASTING USING ALGINATE

Hi everyone . So over the next few special effects lessons in uni I am going to be casting my ear and hand for this semesters prosthetic finial assessment and Fiberglas mound making . So let’s start with ear casting this is all new to me as i will be using a new method and new products so it’s very exciting
So to cast the ear we used alginate that is originally from brown seaweed that grows in cold water . The natural function of alginate is to give flexibility to the seaweed, which made perfect sense as it’s a very flexible casting medium.
Casting the ear was loads of fun to do and really wasn’t as difficult as anticipated if you’d like to.
Things to remember when been in a workshop and using these materials :
• Take note of the health and safety regulations of each product used.
• Make sure the model is comfortable throughout the process. – Ask if they’re okay and talk them through the process while you are doing it.
• Be fully prepared with all products and object you will need to
• It helps to have an assistant as you can’t do this process on your own , one set of hands are not enough.
• Must wear overalls whenever in the workshop to prevent any products getting on any outdoor clothing.
Products you will need :
x2 plastic mixing bowls
x2 paper cups
Paper towels
Cotton wool
cling film
Petroleum Jelly
Alginate
water
Plaster
An extractor fan (for health and safety reasons)
x2 long strips of mod rock that fit round the circumference of the cup
Method :
• cut the paper cups in half in preparation.

• Ask your model to plug up her ear with cotton wool to prevent the products seeping down into the ear canal. Then asked your model to lay down on the desk top -making sure their head is supported and lying as flat as possible.It is vital that the model is comfortable in the position they are laying in as the Alginate needs to be left to cure for up to 5 minutes, which requires the model to sit still.

• moved any stray hairs away from the ear, then smoothing it down by applying a small amount of petroleum jelly with your fingertips.

GOOD TO KNOW : If any point of the ear is touching or very close to the head, insert a small amount of cotton wool under the fold to prop up the ear slightly. This will allow the alginate to manoeuvre around the ear better giving you a clearer cast of the entire ear. Make sure you don’t distort the ear shape by putting too much cotton wool under as this will cause problems later on with your prosthetic .

• cut a section off the cling film out to act as a protective layer between the skin and hair around the ear and the Alginate. then cut a split in middle of the plastic to expose the ear. If needed add a little more petroleum jelly to stick it down on the skin around the ear.
• Once the plastic Is secure place the to top half of a paper cup around the ear to prevent the alginate from leaking. This is when you will need an assistant to hold the cup in place to prevent the alginate from leaking out of the top half of the cup . Remember keep asking if your model is okay to ensure you are not applying too much pressure. As another precaution also wrap a paper towel around the lip of the cup.
• mix up the alginate! Alginate comes in a powdered form which you need to mix with water to begin the vulcanization process (setting/curing). To mix up a batch of alginate it is always best to use only tepid/room temperature. When the alginate is mixed you only will have around 3 minutes of working time before it begins to set. First we poured a cup of tepid water into a plastic bowl. then began to sprinkle in the Alginate directly into the water using your hand to mix it until it is a ‘runny/lumpy porridge’ consistency.
• Before pouring the alginate make sure someone is holding the cup firmly onto the head to prevent any alginate running under the lip of the cup and onto the models head and hair. When pouring it is always best to pour it either behind or in front of the ear making sure it fills up gradually and doesn’t create air bubbles. Once you have poured in the alginate you then need to use your finger to move it around the ear. This is to makes sure there are no air pockets preventing the alginate from reaching the surface of the skin.
• Once poured a the cup must still be held firm until the alginate has set a significant amount. The curing time may differ depending on the type/brand of alginate you are using. Our casts took around 5 minutes to cure completely.
GOOD TO KNOW :If you are unsure if the alginate has set take a look at the alginate left over in your bowl and see if that is completely set. If unsure leave it for another minute. Better leaving it on for too long rather than taking it off too soon.

• Once cured the next step is to remove the mould from the model. To do this you need to follow the direction of the ear and gradually peel away the edges , reaching your fingers gently underneath the mould. Then once lifted from the face, gently pull and lift it towards the back of the head following the ears natural shape. Then remove the plastic bag from the surface of the mould once removed from the head .
• Now you have made a negative it is time to make the plaster positive. To do this you will have to cut another paper cup in half and placed it directly on top of the cup you negative ear cast is in .
• Next step is to go around the edge of the cups joinery with clay to0 act ad s barrier so the plaster will not pour out. Once the joint is completely covered with clay you then need to use Modroc to completely seal the joint .
• Gather a bowl of warm water so you can then dipped each strip of Modroc and removed any excess water. Quickly, then applied the Modroc directly over the top of the clay and smoothed it out to further prevent any plaster spillage. then leave it for a few minutes to harden and set .
• Once dry, mixed up a batch of plaster under the extractor fan (to prevent any plaster dust floating around the work room as this is not good to inhale.
• To do this we began by adding a cup of cold water to a plastic (easy bendable) mixing bowl then gradually sieved handfuls of plaster on top of the water until the surface looked like wet cracked sand. We then left it to stand for a few seconds and then mixed it with our hands to make sure there were no lumps or air bubbles as this will affect the quality of the positive. (The plaster should be of a similar consistency to double cream).
• Then poured the plaster directly into the mould. Make sure the cast is completely full and then continue pouring to create a good base for the positive to stand on. Once poured give the mould a few short sharp taps on the table to encourage the air bubbles to rise to the surface. Then leave the plaster to set for 1-2hrs .
• Once the plaster set remove the plaster bandage ,clay and plastic cups .
• Begin chipping away at the Alginate with a wooden tool to reveal the plaster positive underneath.
• Once all the Alginate is cleared you can then see how well cast come out. Here is what my ear positive looked like!

Evaluation :
Overall I felt the process ran quite smoothly. The final cast of my ear is strong without any air bubbles in the ear which means i can safely sculpt onto it without it braking . I was impressed by the amount of detail the Alginate picked up for example; the holes where I have had my ears pierced and all the skin texture on my ear .
Thanks for reading
Bex 🙂

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