Accu-Cast 880 Blue is an easily mixed alginate that sets in 5–10 minutes. If kept in a sealed container and treated carefully, it can last a few weeks.
Mixing Accu-Cast 880 Blue
The manufacturer recommends mixing it 4 parts water to 1 part Accu-Cast 880 by weight. We have had success mixing it 7 parts water to 1 part Accu-Cast 880 by weight. We prefer mixing this alginate with a kitchen whisk in a bowl, starting at 1 beat per second until the dry powder incorporates into the water. When it does, we increase mixing speed to approximately 3 beats per second for 1–2 minutes (until the mixture is smooth but before it begins to set up). Work in a well-ventilated area and wear a NIOSH-approved respirator whenever working with powdered materials.
Pouring the Aliginate
To begin, be certain that you are working on a flat and level surface. Also, be aware that poured molds typically involve a model that is attached to a work surface surrounded by walls or coddles to contain the mold material during pouring (often referred to as a “flask”). Pour a steady, uniform stream of alginate into the flask to one side of the model (not directly on it) so that the alginate rises up and around the model before covering its top. By enveloping the model in this manner, you help prevent air from getting trapped on its surface. Vibrating the worktable by drumming on it with the bottom of your fists will also help eliminate air bubbles.
Allow the remaining alginate to dry completely in the container; then immerse the container in a bucket of water. This will make it possible to remove the alginate in one large piece rather than peeling it out in chunks. Check local regulations for proper disposal.
Never pour alginate down a drain as it will clog your pipes!