Hi everyone! So, I thought I’d share with you what we have been taught this week during the Special Make-up Effects lesson. This week was very exciting as I got to work with a product I have hear a lot about but unfortunately haven’t had the opportunity to work with yet. Alginate. From my research I found out that Alginate originates from a brown seaweed that grows in cold waters. Sodium Alginate is a natural polysaccharide product that is extracted from the cell wall of the seaweed. The natural function of alginate is to give flexibility to the seaweed, which made perfect sense as I have read that is is a very flexible casting medium.
Casting an the ear was loads of fun to do and really wasn’t as difficult as anticipated if you’d like to see how we did it please continue reading, If you have any questions I will try and answer them ASAP!
So here goes!
Things to remember:
-Abide by the health and safety regulations over 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 so they know what to expect (cold fluids etc).
-Be fully prepared with all products and object you will need to
-It helps to have someone to help you (I will explain why later)
You will need:
x2 plastic mixing bowls
x2 paper cups
Clear plastic bag / clear plastic / cling film
Petroleum Jelly (Vaseline)
Access to water
An extractor fan (for health and safety reasons)
x2 long strips of plaster bandage (Modroc) Roughly 30cms in length
Before starting the casting process we split into groups of three to make sure we all had someone at hand to assist when needed. We also cut the paper cups in half in preparation. During the casting process we made sure to wear overalls to prevent our clothes from being damaged (old clothes will do just fine).
First we asked our model to plug up her ear with cotton wool to prevent the products seeping down into the ear canal. We then asked our model to lay down on the desk top -making sure their head was 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.
Next we then moved any stray hairs away from the ear – smoothing it down by applying a small amount of petroleum jelly with our finger tips.
Tip! If the top of the ear is touching or very close to the head – push 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. For example, when it comes to sculpting on top of the ear cast you will not be sculpting on a replica that is true to the natural shape of the models ear. Possibly resulting in an ill-fitting prosthetic.
Next we cut a section off the plastic bag out to act as a protective layer between the skin and hair around the ear and the Alginate. We then cut a split in middle of the plastic to expose the ear. We then used a little more petroleum jelly to stick it down on the skin around the ear. Always keep health and safety in mind so don’t place the plastic over the models face as this could obstruct her airways. You do not need to add any releasing agent when using Alginate as it has a watery feeling exterior once cured which prevents it sticking to surfaces. It is also really flexible so you can easily bend the product away from what ever you are casting.
Once the plastic was secure we then were able to use to top half of a paper cup as a wall around the ear to prevent the alginate from leaking. This is when you may need a little help! To prevent the alginate from leaking down onto our models head one of us held onto the cup tight, slightly pressing it down onto our models head. Remember keep asking if your model is okay to ensure you are not applying too much pressure. As another precaution we also wrapped paper towel around the lip of the cup.
The next step was to 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 water as the warmer the water the quicker the alginate will solidify. 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. We then began to sprinkle in the Alginate directly into the water using our hand to mix it until it was at a ‘runny/lumpy porridge’ consistency. Once we were happy with the consistency we were ready to cast!
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 makes sure there are no air bubbles preventing the alginate from reaching the surface of the skin. Again, remember to constantly reassure your model and tell then what is going on.
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.
Tip! 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, chances are it has vulcanized enough ready to be removed. If unsure I’d recommend leaving it for another minute. Better leaving it on for too long rather than taking it off too soon!
Although alginate is a flexible product once dry it is still susceptible to tears if not removed correctly. Once cured the next step is to remove the mould from the model. To do this you need to follow the direction of the each and gradually peel away the edges – reaching your fingers gently underneath the mold. Then once lifted from the face, gently swipe it towards the back of the head following the ears natural shape. Then remove the plastic bag from the surface of the mold.
Once the ear is free from the mold you can then sit your model up and prepare for the next step. Now we have made a negative it is time to make the plaster positive. To do this we cut another paper cup in half and placed it directly on top of the cup the mold was in. We then used clay to attach the two cups together.
Tip! This can be quite difficult as the cups are flimsy and may bend when you try to blend the clay out. To help attach the two I found it easier to create 3 or 4 anchor points rather than rolling out a long strip of clay and trying to blend it on. I then filled in the gaps.
Another reason for using the clay is prevent the plaster from leaking out of the joining of the cups as that could be messy! Once the joins are completely covered with clay we went on to using plaster bandage (Modroc). Gathering a bowl of warm water we then dipped each strip of Modroc and removed any excess water. Quickly, we then applied the Modroc directly over the top of the clay and smoothed it out to further prevent any plaster spillage. Once I was happy with the joining of the two cups we then left it for a few minutes to solidify.
Once dry, we 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).
We then poured the plaster directly into the mould. (This is why a bendy bowl is handy as it allows you to use to funnel the plaster in with little or no spillage) 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 mold a few short sharp taps on the table to encourage the air bubbles to rise to the surface – as this will give you a smoother effect. We then left it until next lesson because we ran out of time however if you have the time to run through the full process leave it for around an hour to cure completely before moving onto the next step.
As we had left our ear casts for a long period of time we soaked them in a bucket of water for around half an hour to soften the cup, plaster bandage and Alginate to make the removal process that much easier. You may not need to do this depending on how long you leave the plaster to set for. You may get away with soaking it only for 10 minutes or less.
Once we had soaked the casts we then removed them and began to peel away the cups, plaster bandage (mod-roc) and clay to reveal the the Alginate and plaster underneath.
Once that is done I then began chipping away at the Alginate with a wooden tool to reveal the plaster positive underneath. I had to be extremely careful during this stage as the plaster is also damp making it more susceptible to damage.
Once all the Alginate is cleared we can then see how well cast come out. Here is what my ear positive looked like!
Evaluation / Reflection:
Overall I felt the process ran quite smoothly however we did unfortunately get a small amount of the Alginate in one of our models hair however once it was dry it combed straight out due to it’s flexibility.
Unfortunately there was some air bubbles that restricted the Alginate from getting a clear cast of my ear however the general outline is still there. I would not feel comfortable sculpting on top of this cast as it isn’t strong enough as I think the top of the ear (the scapha) would easily break with minimal pressure. If I had the time I would do the cast again making sure the to move my finger around the entire ear making sure to eliminate any possible air bubbles.
However I was impressed by the amount of detail the Alginate picked up for example; the holes where I have had my ears pierced.
Overall I was a little disappointed about how my cast turned out however, I now feel confident in making a second attempt to try and perfect this skill.
Thanks so much for visiting my blog! I will also be going through the next few steps such as sculpting casting, colouring and applying the appliance at a later date.
Next week we are going to casting our hand too, so stay tuned!
Thanks again, Katy x