This is a simple lamp project consisting of a standard lightbulb socket cast into a concrete cube, with the optional addition of a 3D printed lampshade on top.
- Concrete powder: I used Shapecrete, which had clear instructions on the package for mixing and casting and turned out great. This material is really cool because it can have a claylike consistency then harden into concrete, but at the higher water ratio I used to get a pourable consistency, it acts a lot like regular concrete.
- Concrete mixing materials: Cover your workspace in something like a tarp or brown paper to take care of drips, and have a bowl, stirrer and measuring devices ready for mixing, as well as a water source handy.
- Mold making materials: I used foam board, a hot glue gun, a ruler, a triangle, a pen, double sided carpet tape, and a utility knife.
- Lightbulb socket with cord and switch: This is available in hardware stores - make sure you get the kind that has the cord on the switch, not the side of the socket, because the socket will be totally encased in concrete.
- 3D printer and FDM material
The lamp shown here is 3.5" x 3.5" x 2.5", so you'll need to build a rectangular mold with those inside dimensions. Sheets of foam are great for creating a casting mold, because they don't absorb water, demold easily and leave a smooth surface on the face of the concrete. They can be cut easily with a utility blade - use a triangle or measure carefully to make sure the pieces are square, and don't forget to account for material thickness in your dimensions. Stick the panels together with hot glue - it's okay if the joints aren't perfect, any extra concrete that gets in there can be broken off after demolding. I attempted to seal them with hot glue and it just created a melty mess, but if you want a super clean result you could try using silicone or some other sealant.