This article is an extract of a detailed body casting instruction manual explaining in details how to make a realistic, life size and very elegant plaster sculpture of someone’s torso (or any other bodypart.)
Although this article provides you with enough information to complete a simple body casting project, The full manual is available for download from htpp://www.bodyscape.net.nz and includes much more information than provided here.
The resulting sculpture will be an amazingly detailed reproduction of someone’s body, a durable, faithful and elegant memento. This is an easy, safe, fun and inexpensive project. The manual’s detailed and complete instructions and illustrations will ensure that your project is a success.
Materials and equipment.
This is the list of tools and materials you will need to complete the project.
- One plastic bucket.
- One bag of 1 kg of Alginate
- 5 rolls of plaster bandage
- A few pairs of latex gloves.
- 10 kg of Plaster of Paris.
- 2 or 3 empty soft drink bottles.
- A plastic bowl.
- A power drill and a paint mixer attachment.
- One chip
ush of medium size.
- Cotton balls
- A kitchen scale
Alginate is a natural compound made from seaweed. It is sold as a fine powder which when mixed with water makes a paste that will set and harden in a few minutes. Dentists traditionally use alginate to take tooth impression. It is organic and skin safe.
The manual provides a list of over 100 online shops selling Alginate in the USA, UK, Canada, South Africa, Australia, New Zealand, France and other countries. Download it from htpp://www.bodyscape.net.nz
This section describes the body casting process in
There are two major steps in the process.
• The first step consists of making a mold of the live model.
• The second, casting plaster into that mold.
This is not unlike photography where you first record an image and then print it on paper.
The mold is made of two separate layers. A first layer, which I call the “alginate skin”, captures the skin texture but is too flexible to remember the pose and too fragile to receive liquid plaster. A second layer of plaster bandages must be applied over the alginate to set its position and give the mold enough strength to receive the liquid plaster. This second layer is called the “plaster shell” or “mother mold”.
You will apply a layer of alginate directly on your model’s skin. You will then cover this alginate skin with several layers of plaster bandages to encase the alginate skin in a plaster shell. These are the same kind of bandages that a doctor would use to cast a
oken arm. When the plaster bandages have set, the entire mold is removed from the model and set on the floor, open side up. The whole operation takes no more than half an hour.
A batch of liquid plaster is then mixed and painted or poured inside the alginate mold. After a few hours, the plaster has set and the alginate and bandage mold can be removed to reveal a solid plaster replicate of your model’s body. The rest of this article describes in more detail this simple procedure.
The full manual available from htpp://www.bodyscape.net.nz includes useful tips and hints, safety precautions, measurement expressed in US customary unit, illustrations and photos, an important trouble shooting section and a list of over 100 shops around the world supplying alginate and other necessary tools and materials.
Applying the alginate skin.
This is the most difficult part of the casting process and much of the success of your casting will depend on how well you have done this part.
Mixing the Alginate
Bring the water bottles from the fridge and empty them in your clean plastic bucket. There must be 2.5 litres of cold water. Put on your latex gloves. Cut open the bag of alginate and pour its entire contents in the water. You now need to act quickly and decisively. Your model is ready and waiting.
Plunge the power drill mixing blade into the bucket to mix the alginate to a thick creamy texture. This should be achieved in less than 1 minute.
Applying the alginate
Scoop a bit of the alginate paste in each hand and apply it firmly on your model’s skin. Start from the top of the casting area and work your way down. Do not be shy as you want to push out any air bubble out of the alginate, massage it in firmly in a wiping motion to push out any air. Repeat to construct a thin layer over the entire casting area.
After this first thin layer, apply the rest of the alginate to build up thickness all over the casting area. Expect to build an alginate skin about 1 cm thick or more. Make sure not to leave any thin spots. You do not want to see any skin, showing through the alginate.
You do not have to use all the alginate mix. Apply just enough to construct a layer 1cm thick all over the casting area. Be careful not to set too much alginate on top of the
east as the weight of too much alginate may distort the
east soft tissues which will result in
east looking flatten in the final sculpture.
Constructing the plaster shell.
This is done by applying the wet plaster gauzes over the alginate skin. Three layers are sufficient.
Remove your latex gloves. Pour some water to fill a third of the bucket where you mixed the alginate. It does not matter if there are still bits of leftover alginate in the bucket. This water can be warm.
Soak one roll of plaster gauze by holding it for one second or less in the water, squeeze out excess water and unroll it carefully over the alginate making sure it adheres closely to the alginate as you do not want to create gaps between the soft alginate and the hard plaster shell. Tap gently, do not press it in too strongly or it may distort the underlying alginate. If a strip is too long, you can fold it back onto itself. Repeat with another roll until you have covered the entire casting area, each strip slightly overlapping its neighbour.
You may slightly overlap the alginate skin and have some ends of the plaster gauze applied directly on the model’s skin around the alginate.
Start again for a second layer and then a third if there is enough gauze. If you have some gauze left after the third layer, use it for a fourth layer, reinforcing the edge of the mold.
Releasing the mold.
When the plaster has set, after 5 to 10 minutes, the mold is ready to be released and the model set free. This must not be rushed or you’ll risk ripping off the fragile alginate.
First slide the tip of one or two fingers between the mold and the model’s skin all around the edge of the mold to slowly set it free. Then grab hold of the mold with both hands and ask your model to gently wriggle. It should come free fairly easily. If the model feels that the mold is getting stuck somewhere, reach underneath with one hand and try to free it delicately.
When free, set the mold on a pile of old clothes on the floor, open side up as show on the picture next page. Prop the side walls of the mold with some old clothes to prevent the shell’s walls from opening up and distorting the shape of the mold.
Casting the plaster.
This must be done shortly after the mold has been made. By all means do not wait overnight as the alginate will dry very quickly and become
ittle and fragile.
Mixing the Plaster
Carefully clean the plastic bucket completely free of alginate bits and fill it with 3.5 litres of water Using the plastic bowl, sprinkle 5 kg of plaster powder in the water, do not simply dump it in. You may have weighted the plaster beforehand or weigh each bowl as you go until you have used the required quantity. When you have added all the plaster, it should form a small island at the surface of the water; if not, sprinkle a bit more until it does. Let the plaster soak for a few minutes then stir it gently. Let it rest 5 minutes.
With a paint
ush, paint a thin layer of plaster on the inside of the mold. At first it will be very liquid, run down the walls and puddle at the bottom of the mold. It will soon become creamier and heavier.
You will not be filling up your mold to the
im with plaster. You will construct instead a layer 3 cm thick on the entire inside surface of the mold. You can use the plastic bowl to pour large amounts and then spread it around and push it against the walls with the
If the edges of the plaster cast are untidy, you can smooth them with a wet sponge but I recommend that you do not interfere with freshly poured plaster. Let it set and do any cleaning and finishing required afterwards. Let it set for 3 to 4 hours or more before attempting to unmold, preferably overnight.
To unmold your casting, turn it over and gently peel the plaster gauzes and alginate off the plaster casting. Both plaster shell and alginate skin will be ripped and destroyed in the process. It is therefore a one-off mold that cannot be reused. Pieces of alginate may get stuck in narrow spaces such as skin fold. Delicately pick them up with a small tool, being careful not to scratch the fresh plaster.
A fresh cast is still full of water and very heavy. It is set but wet. You would normally let it dry for several weeks before attempting any sort of finishing. However there are a few things you can do on your wet plaster.
Cleaning the contour.
Care and maintenance.
These supplementary instructions are included in the full manual available for download from htpp://www.bodyscape.net.nz
About the author.
A New Zealander since 1987, French born Olivier Duhamel lives on Waiheke Island near Auckland, New Zealand with his wife Marie-France and their 3 children.
He is a sculptor specialising in the female human form and makes delicately crafted small
Olivier Duhamel’ s creations do not convey any particular message, do not attempt any conceptual or symbolist exploration, nor do they search to be innovative at all cost. They are rather trying to simply capture the beauty and sensuality of his subject of study.
onze works are sold in art galleries across New Zealand and also in Australia, China, France and Belgium.