Hot glue pennies to the inside of each copper coupler; this will form the holder for the candle so cement does not seep thorugh.
Make a mark 3/4 inches high on the inside of the round cardboard container. In the plastic container, mix water and cement with rubber spatula spoon until the consistency is like soft serve ice cream.
Take the first color of spray paint and spray onto the surface of the cement in your container; we used a metallic paint for a touch of shine. After you've sprayed the surface of the cement, use the spatula to swirl the top of the cement with the paint to create the marbled look; be careful not to swirl too much, or the paint color will blend in to the cement and lose the marbled look. Repeat with second paint color.
Spoon cement into cardboard container up to the marked 3/4-inch line. The way to get the best marble effect is to lift cement out of the plastic container and place it in the cardboard container with the bottom of the spoon facing the bottom of the container so that the paint color stays on top. Lift and tap the cardboard container to settle the cement and eliminate air bubbles.
Wait a few minutes for the cement to slightly set. Then press the copper fittings partially into the cement in a triangle arrangement. Let dry for 2-3 hours. Once the cement is fully set, cut away the cardboard box and sand any rough edges. Add candles to complete the display.