A Lesson on Process: Casting Aluminum

“The manner of doing things is often as important as their result” – David Pye

This is especially true in the makeLab where the process of making is celebrated. This semester, makeLab students were asked to focus on dissecting the “making process”. The students engaged in a series of three exercises, each one using a different fabrication process: forming, removing, or joining. The exercises also required a different performance criterion for each process: the ability to bend, provide transparency, or reflect light. One of the groups, made up of Laura Saler, Nate Jemison, and Rob Gurchie, set out to demonstrate and document the forming process of casting aluminum. The group chose aluminum for its performative ability to reflect light, its low melting point as well as its rapid availability in the Metro Detroit area.

The group first rendered the formwork for the aluminum casting in the digital modeling program 3Ds Max, then translated the file to PartWorks and milled the formwork from extruded polystyrene (this was the easy part).  

Then it was time to melt the aluminum. In order to do this, the group needed a Kush head pressure tool to aid in pouring the molten aluminum into the formwork, a kiln to heat and melt the aluminum, and a crucible to fit inside the kiln and hold the aluminum. After researching these tools, the group found that it was uneconomical to purchase any of them. Just two day shipping on the crucible alone would have been $70.  And there was a time factor. The project had to be completed within the week. So the group set out to make their own tools.

 

Laura: “There was definitely value in making our own tools. We were able to customize the tools to meet the needs of the project, and we achieved the same results we would have expected from more expensive commercially made tools.”

For the group, tool making was a constant trial and error process. In order to make their own tools, the group members used other tools, mainly the CNC machine and TIG welder, which they had never used before. This added more uncertainty to the project, but the group accepted that failures would occur before any successes. Each failure pushed them to keep experimenting. As Nate put it, “we failed until we found a way to make it work.”

For example, one issue the group ran into was with the kiln’s insufficient heat production. In order to heat the kiln, the group initially inserted a pipe into the side of the kiln and connected this to a propane torch. Before actually melting the aluminum, the group performed a dry run to remove any impurities from the crucible and to further cure the kiln. During this test, the group discovered that the heat source was unevenly distributed within the kiln. The single propane tank was not strong enough to fuel the kiln. With only two days left to complete the project, the group added an additional tank on the opposite side to provide sufficient heat. After making this and a few other adjustments, the group was successful in melting their scrap aluminum pieces in the kiln. The molten aluminum was then poured into the plaster-covered sprue, connected to the top of the foam formwork. As the aluminum solidified, the foam melted, leaving behind the finished result.

During our interview, the group mentioned possible ways to improve on their process if they were to attempt something similar again, which made me realize the most important part of this exercise was not the outcome, but the process building up to it. It was a learning process, a trial and error process, an inventing process, a hands-on making process. And it all came from the simple idea to cast aluminum.

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