Bodycasting
Bodycasting, also known as life casting, is a process used to create a three-dimensional replica of a person’s body or specific body parts. It involves making a mould directly from the subject’s body using materials such as alginate, silicone or plaster.
Alginate is a popular choice because it is safe and easy to use. It starts as a powder that is mixed with water to form a viscous substance. Once the alginate sets, it captures an exact impression of the hand, foot or other body part. As a casting material, Acrylic One (A1) is easy to process and works very well with alginate. Because A1 expands slightly while curing, it creates a very detailed copy of the original. A1 can be coloured or painted afterwards to create the desired look.
Bodycasting is used for many purposes, including art, sculpture, special effects and medical prosthetics. It is also a personal way to preserve the shape of someone’s body, for example during pregnancy, or as a keepsake of a loved one.
1.0 Pour a small amount of A1 (about 1/3 of the mould) slowly into the mould and gently rotate it. Let the A1 flow through the shape in all directions to reduce trapped air. Repeat this twice.
While mixing, air bubbles can get into the A1. These can become trapped in the mould during pouring, because in some places the air cannot escape.
The best way to mix A1 is with a high-shear mixer. It is available in two sizes: a small mixer for up to 1.5 kg and a large mixer for 1.5 kg or more.
First, start stirring the A1 Liquid and gradually add the A1 Powder. Try to mix in as few air bubbles as possible by keeping the mixer head at an angle and below the surface.
Mix until the A1 mixture is smooth (avoid lumps). Stop mixing, carefully remove the mixer from the A1, and gently stir the A1 a few times with a spatula.
Pour a small amount of A1 (about 1/3 of the mould) slowly into the mould and gently rotate it. Watch closely where the A1 flows. You may immediately see larger bubbles rising, for example at the fingers. For small air bubbles, you can tap gently against the bucket. The walls will now be nicely covered with a thin layer of A1, and the air can escape along the sides. Pour in another 1/3 of the A1 and rotate again. Then pour the remaining A1 into the mould. For the best result, you can pour all the A1 back into the bucket and repeat this twice.
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2.0 I want to paint my object. Which paint can I use?
For indoor use, the A1 object can be finished with acrylic paint, oil paint or lacquer, provided that the adhesion of the paint has been tested beforehand.
If you choose such a paint and a final lacquer (matt or high gloss), we recommend testing first and following these steps:
- make the object indoors,
- let the object dry and cure,
- paint the object (follow the paint supplier’s advice on drying time),
- apply varnish if needed (follow the supplier’s advice on drying time),
- do not use A1 Sealer PLUS.
For outdoor applications, these coating systems can interfere with the breathability of A1, which can cause the coating layer to flake.
3.0 After demoulding, I noticed some lines in my object. What are these?
We call these lines water lines. Water lines in your object can be a sign that you added too much water to your alginate, or that your mould has been standing too long and is already releasing its water.
If there is water in your alginate, you can pour the A1 in and out to mix the water with the A1, then pour it back into the mould.
4.0 Can I colour A1?
Yes, it is possible to colour A1. The base colour of A1 is ivory white. If desired, we have suitable A1 pigments in 10 colours to colour A1 all the way through.
These pigments are highly concentrated and can be added up to a maximum of 2% of the A1. A lower dose is often enough to achieve the desired result.
5.0 Can I paint an A1 object afterwards?
Yes, you can paint your object afterwards. If your object stays indoors, you can use almost any paint, as long as it adheres well to A1 (do a small test first).
Outdoors, only use vapour-permeable wall paint.
6.0 Do I have to use a sealer after I have painted the A1 object?
Do not use a sealer over paint systems, as it will reduce the breathability of the paint.
7.0 What is the drying time, for example for a baby’s hand or foot?
Although A1 seems to cure within a day, final curing takes several days. During this process, moisture is released from the A1 object. The larger the object, the longer this takes. We recommend a curing time of at least 7 days for small objects. For larger objects, it can take 2 weeks or more. The curing time of A1 also depends on the environment and humidity. Because A1 is a breathable material, it constantly absorbs or releases moisture. For objects that will be placed outdoors, we advise using a vapour-permeable paint, coating or sealer system.
8.0 What is the difference between A1 and porcelain gypsum?
We are often asked about the difference between A1 and porcelain gypsum. That’s why we did some tests to compare the two as casting materials for bodycasting.
The first obvious difference is that A1 powder is mixed with our A1 Liquid, while porcelain gypsum is mixed with water. This is reflected in the price, as porcelain gypsum is cheaper per kg.
Mixing both materials is easy. Both can be mixed by hand or with an electric tool, resulting in relatively few air bubbles compared to other materials. A1 feels slightly more viscous.
The working time differs. Porcelain gypsum starts to cure after approx. 6 minutes, while A1 has a working time of approx. 20 minutes. If needed, this can be slowed down or sped up using the A1 additives.
Casting with both materials is very easy because of their viscosity, so both will pick up all the details in your mould. Thanks to its longer working time, A1 gives you a better chance to remove as much trapped air as possible. See our video on how to cast your mould with A1.
The demoulding time is 30 minutes for porcelain gypsum and 60 minutes for A1. You will notice very few air bubbles with both materials. Although A1 can be demoulded after 60 minutes, handle it carefully, as A1 will continue to cure for a few days. Right after demoulding is also the best time to work on your casting, for example to remove bumps caused by air bubbles in your alginate, as the A1 is still soft enough to scrape.
The hardness of both materials is comparable: porcelain gypsum has a Shore hardness of 90 and A1 a Shore hardness of 80.
The base colour of A1 (ivory white) and porcelain gypsum (white) are comparable. A range of colours is available to pigment A1, so you can give your casting a base colour. This makes colouring your casting afterwards easier.
A1 can be laminated with our A1 Triaxial Fibre, which makes A1 perfectly suited for creating lightweight and very strong torso castings.
Even if you work as neatly as possible, no bodycast will be perfect straight after demoulding. Some finishing is always necessary. We noticed that the working time of A1, combined with its adjustable viscosity, even makes it possible to recreate details such as fingernails. Mixing small batches, adding layers on top of each other, sanding and cutting are all possible with A1, which we found to be an advantage over porcelain gypsum.
9.0 There is a milky white substance in my A1. What is this?
After a while, the alginate releases its moisture, which collects in the mould. When you pour the prepared A1 into the mould and then pour it back into the bucket, you may see some moisture in the A1 mixture. Gently mix the A1 again with a spatula and repeat the process (for the best method, see 1.0).
10.0 Some fingertips are missing
Some hand positions cannot be cast properly. This is because air gets trapped in the alginate when casting the A1, which causes fingertips to be missing.
Make sure the air can always escape upwards (diagonally). If a finger is bent, that is not possible. The fingertip should touch the palm, so that the air can still escape upwards through the palm.
See the picture for the correct position of the fingers. The red spots show where air gets trapped and cannot escape. This often results in missing fingertips.
11.0 How to repair an air bubble, for example under a finger
In some cases, air bubbles will appear under a finger. This is because air gets trapped in the alginate when casting the A1. In this case, you can fill the air bubble with A1. Mix a small amount of A1 (possibly with a little Thix A) and apply it into the air bubble with a thin brush. Depending on the size of the air bubble, build up the A1 in small layers. Let the A1 cure a little and then apply more. As the A1 stands a little longer, it becomes thicker, so you can, for example, give the finger a nice rounded shape.
Instruction sheet
