The problem here is a fun one: a plastic quartz clock, found broken at the roadside during a run, had a wrecked face but was otherwise worth saving. The maker decided to replace the face entirely by casting a replica in metal, turning a bit of desert litter into a working clock again.
The path to a good casting was not short. An early mold collapsed for lack of parting powder, and a copper attempt came out incomplete because not enough metal was melted. For the successful run, the clock was disassembled first, with the hands, mounting hardware and battery movement set aside for reuse. Petrobond served as the casting sand, and scrap aluminum went into a crucible in a Devil-Forge furnace. A shallower wooden flask was built for this pour, with steel angle rails bounding the open mold and towels and gloves pressed into service to make up the flask volume. Release powder went on generously, molten aluminum was poured across the open mold, and the casting was water quenched once it had cooled.
The finishing work is what impresses me. A wire brush cup on a cordless drill scrubbed the face, an angle grinder smoothed the edges, and a rotary tool with a carving bit hollowed a square pocket on the rear to seat the clockwork casing. The center hole was drilled through, then the movement, mounting nut, hands and battery went back in. The finished silver face carries raised stylized Arabic numerals one through twelve in a scalloped border, with QUARTZ embossed below the center.
It is not flawless. A crack runs across the face toward the nine, and the maker admits the whole thing took a very long time. Even so, a timelapse shows the clock running, and I agree it came out better than expected.
Project by TheGrowingStack. Watch it on their YouTube channel: