How to Make a Blue Fire Pit

Drive a stake into the ground where you want the center of the fire pit to be. Tie a string that is half the diameter of the pit in length to the post and pull it in a taut circle around the post to mark the outer edge of the pit. Remove the stake and dig out the ground within the circle to a level of 6 inches.

Put the stake back into the center of the circle and shorten the string by 12 inches. Pull the string toward the outer edge then drive another stake at the end of the string. Do this three more times so that you have five stakes in the pit that form a cross pattern. Pull out the center stake.

Place a piece of sheet metal around the outside of the four stakes to form a circle within the larger circle of the fire pit. The wider the sheet, the higher the pit sides will be. Staple the sheet to the stakes so that it doesn't move. Place a second section of sheet metal around the outer perimeter of the fire pit against the ground. Both sheets should be snug against the ground at the base of the pit. This is the form in which you'll pour the concrete to make a donut-shaped fire pit.

Set a carpenter's level across the two sheets to ensure the sides are even with one another. Do this every 12 inches around the circle and adjust the soil underneath, as necessary, to ensure the two sections are completely level. Apply a light coat of motor oil on the inside of the sheets so that they pull off easily once the concrete has cured.

Mix up a batch of concrete in a wheelbarrow per the manufacturer's instructions. Add a bag of blue coloring powder as you are mixing the water and concrete. The bag is made to self-dissolve into the mix.

Pour the concrete in between the two metal circles. Use a shovel to work the concrete completely into the form and remove any air bubbles. Smooth the concrete with a trowel when you reach the top of the form. While the concrete is wet, you can customize the top of it with hand prints, colored pieces of stone or river rocks.

Wait 24 hours then pull the sheet metal away from both sides of the concrete. Cover the pit loosely with a tarp and wait an additional six to seven days before using your new fire pit.