CASTING HANDS IN ALGINATE

Products and equipment needed :
– x1 empty 2 litter bottle
– Scissors
– Vaseline (Not a necessity)
– Access to water
– Power drill
– Squirrel piece to fit onto drill
– x2 Flexible bucket
– Alginate (roughly one and a half bags)
– Plaster
– Flexible bowl
– Metal filing tool

Method :

• First cut the top off a 2 litter bottle using a pair of shape scissors. Make sure there is no sharp pointy bits as this could scratch our models arm during casting.
• Next mix a batch of alginate. As this is a large batch use a flexible bucket and a power drill with a squirrel mechanism attached to the end to mix it better you must mix it this way as you only have three minutes working time before the mix goes off. To make sure you dont make too much alginate measure the amount by filling up the cut bottle leaving 1-2 inches for the plaster .
• Make sure the water is tepid and not hot as this would boost the curing time giving us a shorter working time. Added the water to the bucket and gradually sprinkled in the alginate whilst drilling. Once the mixture is similar to a lumpy custard texture it is ready to pour.
• Asked your model to dangle her hand comfortably into the bottle so you are able to pour it down one side to eliminate bubbles. Get them to wriggled their hand ever so slightly to get rid of any air bubbles attached to their hands. The alginate set pretty quickly however we left it for a further 5 minutes to ensure it was completely vulcanized.

GOOD TO KNOW : If your model has dry skin or suffers from eczema you can add a light layer of petroleum jelly to the hand and wrist prior to mixing the alginate, this may trap extra air bubbles however.

• Once cured, ask your model to wriggle their fingers to allow air into the mould. This is a really important stage as the air needs to gradually work its way down the cast, If you didn’t do this the fingers would suction together resulting in tears in the alginate.
Know mix up a batch of plaster to pour into the hand cast (the negative) to make the positive. To do this 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).
• Don’t pour all the plaster in at first as you want to do a light coating first to make sure we got as much of the detail caught by the alginate. To do this we poured plaster into the finger tips only and then picked up the mould and rolled the plaster around to make sure all the edges we covered .Once you have done that slowly filled up the rest of the mould. continue to fill the mould up to the top to create a base so the hand could stand up once set.
• then leave the plaster to cure for around half an hour. (If possible leave for longer as the plaster was still a little damp and fragile when we took it out). Once set then began to remove the negative.
gently cut away the cup being careful not to dig the scissors into the alginate underneath.
• Once the plastic bottle has been removed then begin to chip away at the alginate piece by piece with a wooden tool. make sure your really careful when doing this as we don’t want to damage the plaster as this will eliminate vital details if scratched .
• Once all the alginate it removed you then have your positive! If there is any air bubbles or imperfections they can easily be filed down gently with a metal tool. When filing away imperfections it is important that you try to follow the natural lines in the skin

Evaluation / Reflection:
Overall I thought the process was quite straight forward . If I was to do this process again I would perhaps make sure our model has all her fingers separated as my model little finger was touching her ring finger. However it is hard to judge the positioning of your hand when you cannot see it whilst it is submerged . A way of overcoming this problem is to use a larger container so our model doesn’t have to be so careful not to touch the edges of the bottle.
Thanks for reading
Bex

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