DIY Foundry: Lost foam + Petrobond Casting (Part 1)

Another casting session. This time, I'm trying out a super-easy lost foam technique: bury the foam pattern in Petrobond sand. After ramming, the petrobond should maintain its shape, even as the molten aluminum is vaporizing the foam pattern.

Investment casting typically involves coating the pattern with layers of ceramic slurry, waiting for it to dry, burning out the pattern and finally pouring. This technique allows me to skip most of these steps.

Patterns were drawn in Inkscape, converted to gcode with MeshCAM, built by my homemade CNC foam cutter. Gating and vents were attached by hotglue. My attempts to use was to attach foam gating to foam patterns failed. Hotglue seemed to work pretty well, although I will be experimenting to find a better alternative.

Disclaimer: This is dangerous. If you've worked in a foundry for 25 years, I respect your experience and value your suggestions... but please don't imagine that I am putting myself forward as the picture of safety.. or industry standard practice.
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