Concrete watch

Fashion

This is a Casio G-Shock with a concrete housing. The concrete is cast onto a 3D printed plastic frame that has a snug fit to the digital module, and fixed lugs for a NATO style strap. With this plastic frame as the interface, there is no direct contact between the digital module and the concrete, and the loads through the strap can be supported entirely by the plastic.

The fit is snug with no rattling, like a very light press-fit, and the lugs are set slightly in from the case back so the strap holds the module in, and the whole assembly feels solid. On the plastic frame, I added some bars like rebar to give the concrete something to flow around and grasp.

I 3D printed the cast with an extra plug to make it easier to de-mold. Of the in-house mold release agents I tried, vaseline worked better than extra virgin olive oil, and beeswax didn’t work well. I let the concrete cure wet in a plastic bag for a couple days.

Modeling was in Rhino, and the music was in Ableton.