Concrete is a wonderfully adaptable medium. It can be formed in a variety of shapes with varying textures and colors. In fact you can make concrete tiles and achieve more varied colors and textures than can be purchased. If you have several molds, you can practice several ornamental techniques at once, since the basic concrete mix is the same.
Instructions
Mix, pour, and level the concrete.
1. Mix the concrete according to package directions. Follow the manufacturer's directions to add the color pigment of your choice into the mix.
2. Spray the inside of the mold with cooking oil. This will help the concrete remove from the mold smoothly when it has dried.
3. Fill the mold half way. Tap on the outside of the mold with a hammer in several spots to remove air pockets. Be sure to tap on the bottom as well as the sides.
4. Fill the mold the rest of the way and remove air pockets. The mold should look full when done.
5. Level the surface by pulling the 2 by 4 board across the top of the mold. Move the board back and fourth slightly as you go, to help compress the concrete. If you have a low spot, toss the extra bits of wet concrete into that place and level the surface again.
6. Smooth the surface with a hand trowel. Let the concrete set until the surface water disappears and the concrete loses its sheen. The time will vary depending on weather conditions.
Add a broom finish to one concrete tile.
7. Draw the stiff whisk broom across the surface of the concrete. It will leave fine lines in the surface. You can make a pattern with the lines or apply them randomly.
Use a broom with thick bristles to create a rough surface; this is great for steps and ramps. Or use a fine-bristled broom for a smoother surface.
8. Rinse the broom bristles frequently as you work. Shake out the extra water completely before you return the broom to the concrete surface.
9. Use a trowel or putty knife to smooth and shape the edges.
Add swirls of color to a second concrete tile.
10. Mix dry pigment, cement, and fine sand in a 1:6:6 ratio. Mix completely.
11. Scatter the pigment mixture onto the concrete. You can let it fall randomly or distribute it in a swirling pattern.
12. Wait until the pigment moistens from the water in the concrete.
13. Trowel the surface, working the pigment into the concrete. Smooth the surface as you work.
14. Use a trowel or putty knife to smooth and shape the edges.
Cure the concrete.
15. Place a polyurethane sheet over the mold to lock in moisture.
16. Leave the concrete in the mold in a warm, dry spot for at least three days.
17.Gently tap the exterior of the mold to loosen the concrete. Remove the concrete tile from the mold.
The concrete will continue to cure and become stronger for 28 days, so handle it gently at first.
