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Step 3: Building the Support for the Paper Mold

Picture of Building the Support for the Paper Mold

Using cardstock paper will lead to a very nice smooth concrete surface, but when I did my first test pouring with just the paper mold, I encountered two problems. The first was that while in general, the paper held the concrete really nice with nothing leaking, the damp paper expanded a bit and this caused the triangular planes to bend outwards.

An outer layer of cardboard fixes this problem. The second problem was that even with the cardboard added, the mold was still flexible. The image below shows how it can be squished.