Translucent Cement DIY (+ Constellation Installation)

After discovering the cool-ness that is translucent cement and finding nepheron's Instructable, I started dreaming up ways to use this material combination.

I started playing around with nature-based themes and ended up making 56 cement panels embedded with monofilament. Each panel represents one constellation – the sum represents all constellations found in all seasons in the Northern Hemisphere.

I hung each panel on galvanized steel mesh spread taut across a metal pipe frame that rests 4 feet above a layer of sod. The final piece was set up at night on a city sidewalk under a street light as part of an art show. People could then lay on the sod and look up to see the stars :)

Materials for each cement panel:

IKEA tupperware (for the mold)
Fishing line and/or plastic rods (to transmit light)
Armature wire (to hang the pieces)
Oil-based clay
Portland cement or high quality concrete

Step 1: Prepare a Flat Layer of Oil-based Clay

After a few experiments, I found that the best way to secure the monofilament in a pattern was to use a very flat layer of oil-based clay. To make the layer very flat, I used a marble rolling pin to create a layer slightly larger than my piece of tupperware and about .25 inches thick.

Step 2: Place Layer of Clay Inside Tupperware

Place the flat layer of clay into your tupperware container. Make sure that the clay fits snugly and hugs each side (otherwise the cement will find its way below the clay and can potentially ruin your mold).

I cut the clay layer based on the size of the tupperware opening, which is larger than the bottom, and then slid it into the tupperware so that it came up a bit on each edge. I then used a small knife to cut the clay closer to the bottom and used my finger to smooth out the sides.

Step 3: Transfer Pattern to Clay

To transfer my pattern to the clay, I copied the constellation onto a piece of paper and placed it onto the clay. I then used a pin to make a little hole in the clay. After removing the paper, I used the larger plastic rods, cut into 1-inch segments, to represent the constellation.

Step 4: Add Wire Hooks to Hang the Panel (optional)

Because I was planning to hang each panel, I added hooks to the mold.

Step 5: Fill the Remainder of the Mold With Monofilament

Fill the remainder of your mold with strands of monofilament. I used fishing line cut into 1-2 inch segments.

Step 6: Mix Cement and Pour Into Mold

Mix your cement with water into a slightly fluid consistency and pour it into your mold about 1/2 inch from the clay layer. Make sure to jiggle the mold a little bit to remove air bubbles.

Step 7: Let Dry (ideally Overnight)

Let the cement dry, ideally overnight, though you can get away with as little as 20 minutes depending on your cement manufacturer.

Step 8: Remove From Mold and Clean Up the Panel

Remove your panel from the mold after it has dried. It usually comes out pretty easily if you loosen the sides of the tupperware. The clay should also peal off relatively easily once out of the mold.

I then used nail clippers to clip each strand so that it lays relatively flush with the cement on both sides.

Feel free to also sand all the side (I didn't do this though).