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The Great Iron Pour | The Molding Process

March 13, 2018

The Molding Process for Iron Pour The first week of ECS we focused on making our artworks, working towards getting all of our pieces into wax. For many of the students, the molding process started out as working with water-based clay instead of going straight into working with wax. Using clay makes much better pieces of artwork in the end. Clay is a much easier medium to work with compared to wax and because of this, we can get more detail on our art before we cast it in wax. We are using a petroleum-based microcrystalline wax which is very difficult to work with because it is very brittle when cold, burns skin when it is hot and gets mealy/grainy if you work with it in your hands too much. After each artwork was completed, we made plaster molds of the clay to create a negative image ready to be transferred into wax. There are two main types of plaster molds that we have been making: two-part molds and reliefs. A two-part mold consists of a clay work sandwiched in-between two plaster molds, each taking an imprint of either side. After the plaster sets, the clay is scraped out giving two plaster negatives. The two halves are then put back together using a register to make sure they are aligned properly and held together using inner tubes from bike tires. Wax is then poured in from a sprue (a pathway through which the wax can flow) giving an exact replica of the original artwork that was made in clay. A relief is a mold taken of something that has a flat side. The piece is laid in a bucket, flat side down, and plaster is poured in making a mold. After the plaster sets, we take it from the bucket and scrape out the clay leaving a perfect impression of what we want to make in the wax. After pouring wax into our molds often the only way to extract it is to use a chisel and break the plaster, leaving artworks in wax. Most plaster molds were used only one time. In a process called “Wax Chasing”, we finished the wax surfaces using tools such as soldering irons, hot plates, dental molding tools, and clay tools. Although tedious, this process makes impeccable artwork if done right. We finished almost all our wax artworks and are ready to attach them to sprue systems, which will allow the molten iron flow into our artworks.

The Molding Process for Iron Pour