Getting Your Alginate Mix Right
Alginate is simple to use. But the effectiveness lies in correctly following the mix ratio and then applying the mixture properly on the model. Be particularly careful about the measurements.
Alginate is the material of choice for making body molds for life casting. This is an organic material that is derived from naturally occurring seaweed. It is considered safe for the human skin and will not harm the model or the artist in any manner.
It is easy to mix and apply as well. All you have to do is mix the alginate powder with water to get a smooth paste. The mixing ratio will be specified in the instruction manual and can vary from 3:1 to even 7:1 (water to powder) depending on the formulation, set rate and other factors.
But be careful with the water quality. Hard water will cause lumpiness like cottage cheese. If the water has too much mineral content the alginate may not set at all. When in doubt about the water quality use distilled water (available from most grocery stores) or at the very least bottled water.
However, care is required when measuring the alginate for the mix. The powder is compressible in nature which can cause the density to vary when measuring by volume. Therefore, mixing 3 cups of water to 1 cup of alginate can play havoc with the consistency of the alginate mix – it may turn out too runny or even too thick which in turn affects the application and quality of the body mold.
If you want to get the proportions right, you have to weigh the alginate prior to adding it to the mixing container. This will be accurate and when mixed properly, will yield the right texture and consistency.
Once mixed, the alginate has to be applied quickly as it comes with a short set time. However, you cannot rush the application when working on a living and breathing human being. Special care is needed when working on the model’s face. This is why artists usually mix the powder in small batches that they can handle before the mix starts to set in the container itself.
You can easily source your choice of alginates online from the EnvironMolds website, www.artmolds.com. Along with the varied art materials, tools and supplies you need, you will also find helpful instructions and learning aids to assist you in your mold making and life casting.